Exploding Galaxies and other Catastrophysics

CDMS-2's 1-sigma dark matter result.

2009-12-18T12:48:00.003-05:00

After much speculation the CDMS-2 "dark matter detection result" announced yesterday turns out to be 2 events with an expected background rate of 0.8 events in the 2007-2008 time frame of the experiment (SciAm news piece).

Exactly two events would happen by chance ~14% of the time (>=2 events would happen 20% of the time), so we're basically talking about a ~1 sigma result. Meh. Hardly impressive. It'd take 10 events under a 0.8 count background rate to get me excited.

Interesting Astrophysics: Dec 07 to 18

2009-12-18T10:18:00.002-05:00

Not a white christmas but a windy one: Razoumov, Westmoquette et al, Rubin et al, Vanzella et al, Crenshaw et al, and Kobulnicky et al are all wind-related papers or preprints (and mainly on galactic winds). Another paper of particular note is Welsh et al's amazing 3-D mapping of the local neutral ISM (within 300 pc) using NaI and CaII absorption line spectroscopy toward 1857 nearby early-type stars.

Galaxies and Starbursts

Damped Lyα Absorber Kinematics and Outflows from Starburst Galaxies
Razoumov, Alexei O., 2009, The Astrophysical Journal, Volume 707, Issue 1, pp. 738-749.
PDF (1.84 MB) | HTML

VLT/FLAMES-ARGUS observations of stellar wind-ISM cloud interactions in NGC 6357
Westmoquette, M. S.; Slavin, J. D.; Smith, L. J.; Gallagher, J. S., III, 2009, MNRAS, in press
Full Text: HTML, PDF (Size: 2563K)

PAH processing in a hot gas
E. R. Micelotta, A. P. Jones, A. G. G. M. Tielens, arXiv:0912.1595 [ps, pdf, other]
Comments: 16 pages, 11 figures, accepted for publication in Astronomy and Astrophysics

From their abstract: "The PAH lifetime in a tenuous hot gas (n_H ~ 0.01 cm^-3, T ~ 10^7 K), typical of the coronal gas in galactic outflows, is found to be about thousand years, orders of magnitude shorter than the typical lifetime of such objects. Conclusions: In a hot gas, PAHs are principally destroyed by electron collisions and not by the absorption of X-ray photons from the hot gas. The resulting erosion of PAHs occurs via C_2 loss from the periphery of the molecule, thus preserving the aromatic structure. The observation of PAH emission from a million degree, or more, gas is only possible if the emitting PAHs are ablated from dense, entrained clumps that have not yet been exposed to the full effect of the hot gas."

The Persistence of Cool Galactic Winds in High Stellar Mass Galaxies Between z~1.4 and ~1
Kate H. R. Rubin, Benjamin J. Weiner, David C. Koo, Crystal L. Martin, J. Xavier Prochaska, Alison L. Coil, Jeffrey A. Newman, arXiv:0912.2343 [ps, pdf, other]
Comments: Submitted to ApJ. 25 pages, 19 figures, Figure 2 reduced in resolution. Uses emulateapj format

From their abstract: "We present an analysis of the MgII 2796, 2803 and FeII 2586, 2600 absorption line profiles in coadded spectra of 468 galaxies at 0.7 < z < 1.5. ... The outflows
have hydrogen column densities N(H) > 10^19.3 cm^-2, and extend to velocities
of ~500 km/s. While galaxies with SFR > 10 Msun/yr host strong outflows in both
this and the W09 sample, we do not detect outflows in lower-SFR (i.e., log
M_*/Msun < 10.5) galaxies at lower redshifts. Using a simple galaxy evolution
model which assumes exponentially declining SFRs, we infer that strong outflows
persist in galaxies with log M_*/Msun > 10.5 as they age between z=1.4 and z~1,
presumably because of their high absolute SFRs. Finally, using high resolution
HST/ACS imaging in tandem with our spectral analysis, we find evidence for a
weak trend (at 1 sigma significance) of increasing outflow absorption strength
with increasing galaxy SFR surface density."

The unusual NIV]-emitter galaxy GDS J033218.92-275302.7: star formation or AGN-driven winds from a massive galaxy at z=5.56
E. Vanzella, A. Grazian, M. Hayes, L. Pentericci, D. Schaerer, M. Dickinson, S. Cristiani, M. Giavalisco, A. Verhamme, M. Nonino, P. Rosati, arXiv:0912.3007 [ps, pdf, other]
Comments: 13 pages, 9 figures. Accepted for publication in Astronomy and Astrophysics

The central energy source of 70micron-selected galaxies: Starburst or AGN?
M. Symeonidis, D. Rosario, A. Georgakakis, J. Harker, E. S. Laird, M. J. Page
Comments: 20 pages, 14 figures, accepted for publication in MNRAS

It is starbursts.

Model analysis of the very high energy detections of the starburst galaxies M82 and NGC 253

E. de Cea del Pozo, D. F. Torres, A. Y. Rodriguez, O. Reimer, arXiv:0912.3497 [ps, pdf, other]
Comments: 6 pages, 3 figures, 2 tables, 2009 Fermi Symposium, eConf Proceedings C091122

Black Holes and AGN

The Geometry of Mass Outflows and Fueling Flows in the Seyfert 2 Galaxy Mrk 3
D.M. Crenshaw, S.B. Kraemer, H.R. Schmitt, Y.L. Jaffe, R.P. Deo, N.R. Collins, T.C. Fischer, arXiv:0912.2420 [ps, pdf, other]
Comments: 22 page, 7 figures, accepted for publication in the Astronomical Journal

Their abstract: We present a study of the resolved emission-line regions and an inner dust/gas disk in the Seyfert 2 galaxy Mrk 3, based on Hubble Space Telescope observations. We show that the extended narrow-line region (ENLR), spanning ~4 kpc, is defined by the intersection of the ionizing bicone of radiation from the AGN and the inner disk, which is not coplanar with the large-scale stellar disk. This intersection leads to different position and opening angles of the ENLR compared to the narrow-line region (NLR). A number of emission-line arcs in the ENLR appear to be continuations of dust lanes in the disk, supporting this geometry. The NLR, which consists of outflowing emission-line knots spanning the central ~650 pc, is in the shape of a backwards S. This shape may arise from rotation of the gas, or it may trace the original fueling flow close to the nucleus that was ionized after the AGN turned on."

Stars, Supernovae and Planets

OB Stars & Stellar Bowshocks in Cygnus-X: A Novel Laboratory Estimating Stellar Mass Loss Rates
Henry A. Kobulnicky, Ian J. Gilbert, Daniel C. Kiminki, arXiv:0912.1314 [ps, pdf, other]
Comments: 49 pages, 19 figures; Accepted for publication in ApJ; full-resolution color figure version available at this http URL; comments invited

CoRoT-7 b: Super-Earth or Super-Io?
Rory Barnes, Sean N. Raymond, Richard Greenberg, Brian Jackson, Nathan A. Kaib, arXiv:0912.1337 [ps, pdf, other]
Comments: 13 pages, 3 figures, accepted to ApJ Letters

The simultaneous formation of massive stars and stellar clusters
Rowan J. Smith, Steven Longmore and Ian Bonnell, 2009, MNRAS, 400, 1775
Full Text: HTML, PDF (Size: 20619K)

Updated stellar yields from Asymptotic Giant Branch models
Amanda I. Karakas, arXiv:0912.2142 [ps, pdf, other]
Comments: Accepted for publication in MNRAS; 15 pages

New 3-D gas density maps of NaI and CaII interstellar absorption within 300pc
Barry Y. Welsh, Rosine Lallement, Jean-Luc Vergely, Severine Raimond, arXiv:0912.3040 [ps, pdf, other]
Comments: A&A accepted

The NaI and CaII distributions are quite different. A very impressive piece of work.

Numerical Methods and Theoretical Astrophysics

Astrophysical turbulence
Axel Brandenburg, Aake Nordlund, arXiv:0912.1340 [ps, pdf, other]

Comments: 80 pages, 24 figures, submitted to Reports on Progress in Physics. For higher figure quality and more frequent revisions see this http URL

Detailed Decomposition of Galaxy Images. II. Beyond Axisymmetric Models
Chien Y. Peng, Luis C. Ho, Chris D. Impey, Hans-Walter Rix, arXiv:0912.0731 [ps, pdf, other]

Comments: 41 pages, 22 figures, AJ submitted. Comments welcomed. Full resolution version of this paper is available at: this http URL

Dynamical Models for the Formation of Elephant Trunks in H II Regions
Jonathan Mackey, Andrew J. Lim, arXiv:0912.1499 [ps, pdf, other]

Comments: 19 pages, 11 figures, accepted for publication in MNRAS. Version with high resolution figures available at this http URL

XMM-Newton AO-9 accepted proposals announced

2009-12-15T09:54:00.002-05:00

Speaking of XMM-Newton, the results of AO-9 observing proposal round have just been made available.

The list of XMM-Newton proposals accepted by the AO-9 Observing Time
Allocation Committee (OTAC) and associated proposal abstracts are
available at:

http://xmm.esac.esa.int/external/xmm_news/otac_results/ao9_results/

The Principal Investigators of submitted proposals have been informed
about the results of the OTAC evaluation by e-mail. The e-mail
contains the details about the second phase proposal submission for
successful observations, which will need to be done via the XMM-Newton
Remote Proposal Submission System (XRPS). The XRPS will be closed on
the 5th of February 2010 at 13:00 UT.

AO-9 observations will start to be routinely performed in May 2010.

Happy 10th birthday, XMM-Newton

2009-12-10T09:37:00.003-05:00

From the XMM-Newton mailing list:

10 Years in Orbit: HAPPY BIRTHDAY, XMM-Newton!

Today, XMM-Newton is celebrating its 10th anniversary. On the 10th of
December 1999 at 14:32 GMT the European Space Agency's XMM-Newton
observatory was launched and started exploring the wonders of the
X-ray universe.

During its first decade of operations, XMM-Newton has supplied new
data to every aspect of astronomy, improving our understanding from
nearby comets to the most distant quasars and gamma-ray bursts.

A dedicated web site celebrating this event is available at:

http://xmm.esac.esa.int/external/xmm_news/items/10th_Anniversary/

We wish all the best to XMM-Newton for the years to come.

We take this opportunity to thank you all for your continued support
and interest in the mission.

The ESA website for XMM-Newton produced the highlights poster shown above (higher resolution versions available here). Of course M82, everyone's favorite starburst galaxy with a galactic wind, features prominently.

Interesting Astrophysics: Nov 23 to Dec 04, 2009

2009-12-04T09:31:00.002-05:00

In honor of the Thanksgiving Day Holiday here in the US the preprint server has produced a veritable feast of interesting papers over the last two weeks.

Of particular note are the following.

Radio spectra of everyone's favorite starbursts galaxies: M82, NGC 253 and Arp 220 (Williams & Bower). Cosmological N-body/SPH simulations affirming the importance of galactic winds, only not quite in the normal way (Oppenheimer et al).

An apparently physically large (6+ kpc) and powerful wind in the AGN SDSS J0318-0600 (Dunn et al), but note that... Krug et al find that AGN probably do not play a significant role in driving the outflows from most Seyfert galaxies, except possibly the high velocity outflows in some Seyfert 1s. Camus et al and Falceta-Goncalves et al have interesting, but very different, simulations of filamentary structures in the Crab Nebula and NGC 1275 respectively (The HST press release image of NGC 1275 [Fabian et al] is shown above).

Sadakane et al find high velocity narrow Na I absorption lines in the spectrum of Nova V1280 Sco. Bowler et al find that massive planets appear significantly more common around A stars than G stars.

Galaxies and Starbursts

The properties of the stellar populations in ULIRGs II: the star formation histories and evolution
Javier Rodriguez-Zaurin, C.N. Tadhunter, R.M. Gonzalez-Delgado, arXiv:0911.4052 [ps, pdf, other]
Comments: Accepted for publication in MNRAS. The paper contains 16 pages, 6 figures and 7 tables

GALEX Ultraviolet Imaging of Dwarf Galaxies and Star Formation
Deidre A. Hunter, Bruce G. Elmegreen, Bonnie C. Ludka, arXiv:0911.4319 [ps, pdf, other]
Comments: 28 pages, 22 figures, 7 tables, to be published in Astronomical Journal

Forty Years of Research on Isolated Galaxies
J. W. Sulentic, arXiv:0911.5663 [ps, pdf, other]
Comments: 8 pages - to appear in the proceedings of 'Galaxies in Isolation: Exploring Nature vs. Nurture', held in Granada, Spain 12-15 May 2009. Editors: L. Verdes-Montenegro, A. del Olmo and J. Sulentic. PASP Conference Series

Evaluating the Calorimeter Model with Broadband, Continuous Spectra of Starburst Galaxies Observed with the Allen Telescope Array
Peter K. G. Williams, Geoffrey C. Bower, arXiv:0912.0014 [ps, pdf, other]
Comments: 44 pages, 15 figures, ApJ accepted

Their abstract: "Although the relationship between the far-infrared and cm-wave radio luminosities of normal galaxies is one of the most striking correlations in astronomy, a solid understanding of its physical basis is lacking. In one interpretation, the "calorimeter model," rapid synchrotron cooling of cosmic ray electrons is essential in reproducing the observed linear relationship. Observed radio spectra, however, are shallower than what is expected of cooled synchrotron emission. In Thompson et al. (2006), a simple parameterized model is presented to explain how relatively shallow observed spectra might arise even in the presence of rapid synchrotron cooling by accounting for ionization losses and other cooling mechanisms. During the commissioning of the 42-element Allen Telescope Array, we observed the starburst galaxies M82, NGC 253, and Arp 220 at frequencies ranging from 1 to 7 GHz, obtaining unprecedented broadband continuous radio spectra of these sources. We combine our observations with high-frequency data from the literature to separate the spectra into thermal and nonthermal components. The nonthermal components all steepen in the cm-wave regime and cannot be well-modeled as simple power laws. The model of Thompson et al. is consistent with our M82 results when plausible parameters are chosen, and our results in fact significantly shrink the space of allowed model parameters. The model is only marginally consistent with our NGC 253 data. Assuming the Thompson et al. model, a steep electron energy injection index of p = -2.5 is ruled out in M82 and NGC 253 to >99% confidence. We describe in detail the observing procedures, calibration methods, analysis, and consistency checks used for broadband spectral observations with the Allen Telescope Array."

Feedback and Recycled Wind Accretion: Assembling the z=0 Galaxy Mass Function
Benjamin D. Oppenheimer, Romeel Davé, Dušan Kereš, Mark Fardal, Neal Katz, Juna A. Kollmeier, David H. Weinberg, arXiv:0912.0519 [ps, pdf, other]
Comments: 15 pages, 6 figures, submitted to MNRAS

Black Holes & AGN

The Quasar Outflow Contribution to AGN Feedback: VLT Measurements of SDSS J0318-0600
Jay P. Dunn, Manuel A. Bautista, Nahum Arav, Maxwell Moe, Kirk T. Korista, Elisa Costantini, Chris Benn, Sara Ellison, Doug Edmonds, arXiv:0911.3896 [ps, pdf, other]
Comments: Accepted for publication in ApJ, 57 pages, 14 figures

From their abstract: "Due to the uncertainty in the location of the dust extinction, we arrive at two viable distances for the main ouflow component from the central source, 6 and 18 kpc, where we consider the 6 kpc location as somewhat more physically plausable. Assuming the canonical global covering of 20% for the outflow and a distance of 6 kpc, our analysis yields a mass flux of 120 M_sun yr^-1 and a kinetic luminosity that is ~0.1% of the bolometric luminosity of the object. Should the dust be part of the outflow, then these values are ~4x larger. The large mass flux and kinetic luminosity make this outflow a significant contributor to AGN feedback processes."

Neutral Gas Outflows and Inflows in Infrared-Faint Seyfert Galaxies
Hannah B. Krug, David S. N. Rupke, Sylvain Veilleux, arXiv:0911.3897 [ps, pdf, other]
Comments: 50 pages, 12 figures, accepted for publication in ApJ

From their abstract: "The present paper describes the results from a search for outflows in 35 infrared-faint Seyferts with 10^9.9 < L_IR/L_sun < 10^11, or, equivalently, star formation rates (SFR) of ~0.4 -- 9 solar masses per year, to attempt to isolate the source of the outflow. We find that the outflow detection rates for the infrared-faint Seyfert 1s (6%) and Seyfert 2s (18%) are lower than previously reported for infrared-luminous Seyfert 1s (50%) and Seyfert 2s (45%). The outflow kinematics of infrared-faint and infrared-bright Seyfert 2 galaxies resemble those of starburst galaxies, while the outflow velocities in Seyfert 1 galaxies are significantly larger. Taken together, these results suggest that the AGN does not play a significant role in driving the outflows in most infrared-faint and infrared-bright systems, except the high-velocity outflows seen in Seyfert 1 galaxies."

Radiation-Driven Outflows in Active Galactic Nuclei
Daniel Proga, Ryuichi Kurosawa, arXiv:0912.0565 [ps, pdf, other]
Comments: 9 pages, 5 figures, in Recent Directions In Astrophysical Quantitative Spectroscopy And Radiation Hydrodynamics: Proceedings of the International Conference in Honor of Dimitri Mihalas for His Lifetime Scientific Contributions on the Occasion of His 70th Birthday (AIP Conference Proceedings 1171)

Interstellar Medium / Hydrodynamics

Flows along cometary tails in the Helix planetary nebula NGC 7293
John Meaburn, Panos Boumis, arXiv:0911.4843 [ps, pdf, other]
Comments: 8 pages, 4 figures, accepted for publication in MNRAS

Properties of extra-planar HI clouds in the outer part of the Milky Way
L. Dedes, P.W.M Kalberla, arXiv:0911.4839 [ps, pdf, other]
Comments: 9 pages, 5 figures, 3 tables, Accepted for publication in A&A

Observations of 'wisps' in magnetohydrodynamic simulations of the Crab Nebula
N. F. Camus, S. S. Komissarov, N. Bucciantini and P. A. Hughes, 2009, MNRAS, 400, 1241
Full Text: HTML, PDF (Size: 7435K)

Turbulence and the formation of filaments, loops and shock fronts in NGC 1275 in the Perseus Galaxy Cluster
D. Falceta-Goncalves, E. M. de Gouveia Dal Pino, J. S. Gallagher, A. Lazarian, arXiv:0912.0545 [ps, pdf, other]
Comments: accepted by ApJ Letters

X-ray Astronomy

Methods for Estimating Fluxes and Absorptions of Faint X-ray Sources
Konstantin V. Getman, Eric D. Feigelson, Patrick S. Broos, Leisa K. Townsley, Gordon P. Garmire, arXiv:0912.0202 [ps, pdf, other]
Comments: Accepted for publication in The Astrophysical Journal. 39 pages, 15 figures

Stars, Supernovae and Planets

Introduction to nuclear astrophysics
Christian Iliadis, arXiv:0911.3965 [ps, pdf, other]
Comments: Proceedings of the 5th European Summer School on Experimental Nuclear Astrophysics, Santa Tecla, Italy, 2009, 20 pages, 4 figures, 1 table

Molecular Clouds as a Probe of Cosmic-Ray Acceleration in a Supernova Remnant
Yutaka Fujita, Yutaka Ohira, Shuta J. Tanaka, Fumio Takahara, arXiv:0911.4482 [ps, pdf, other]
Comments: Accepted for publication in ApJ Letters

Discovery of Multiple High-Velocity Narrow Circumstellar Na I D Lines in Nova V1280 Sco
Kozo Sadakane, Akito Tajitsu, Sahori Mizoguchi, Akira Arai, Hiroyuki Naito, arXiv:0911.5229 [ps, pdf, other]
Comments: Accepted for PASJ letter, 5 pages, 8 figures

Retired A Stars and Their Companions. III. Comparing the Mass-Period Distributions of Planets Around A-Type Stars and Sun-Like Stars
Brendan P. Bowler, John Asher Johnson, Geoffrey W. Marcy, Gregory W. Henry, Kathryn M. G. Peek, Debra A. Fischer, Kelsey I. Clubb, Michael C. Liu, Sabine Reffert, Christian Schwab, Thomas B. Lowe, arXiv:0912.0518 [ps, pdf, other]
Comments: Accepted by the Astrophysical Journal; 15 pages, 15 figures

From their abstract: "Thus, the properties of planets around A stars are markedly different than those around Sun-like stars, suggesting that only a small (~ 50%) increase in stellar mass has a large influence on the formation and orbital evolution of planets."

Other

A Multilingual on-line Dictionary of Astronomical Concepts
M. Heydari-Malayeri, arXiv:0911.4687 [pdf]

Comments: 3 pages, Interactive dictionary of Astronomy and Astrophysics, see: this http URL

BBC discusses costs of ESA Cosmic Vision contenders

2009-12-02T08:53:00.003-05:00

An article on the BBC by Jonathan Amos discusses the contenders for the two slots in ESA's Cosmic Visions program for 2017-2018 launches. Interestingly the article's focus is on the costs (see graph taken from article), but it also has a nice description of each mission (many of which I hadn't heard of).

The missions, and my shorter summary of their nature and aims, are:

SPICA: Joint ESA/JAXA infrared space telescope (5 to 210 micron wavelength range) with a 3.5m primary mirror.
Euclid: Map mass distributions using baryonic acoustic oscillations and weak lensing.
PLATO: A planet hunter with a particular emphasis on finding Earth-like and super-earth terrestrial planets using milli-magnitude accuracy photometry.
Solar Orbiter: Study the Sun and Solar wind from a relatively close-in orbit (as close as 48 Solar radii, it claims).
Marco Polo: Joint ESA/JAXA sample return mission from a near-earth asteroid. Note the high cost!
Cross-Scale: Study MHD plasma properties in the terrestrial magnetosphere and bow shock. 7 ESA spacecraft forming 2 nested tetrahedra with a shard corner. (International collaboration will produce the optimum fleet of 12 spacecraft in 3 nested tetrahedra.) High cost!

Interesting Astrophysics: Nov 16 to 20

2009-11-20T08:55:00.002-05:00

Its a quiet week in terms of interesting papers and preprints. Given the small number of papers no added introduction to them is necessary.

Galaxies and Starbursts

On the interstellar medium and star formation demographics of galaxies in the local universe
Matthew S. Bothwell, Robert C. Kennicutt Jr, and Janice C. Lee, 2090, MNRAS, 400, 154
Full Text: HTML, PDF (Size: 1632K)

Photodissociation chemistry footprints in the Starburst galaxy NGC 253
Sergio Martin, J. Martin-Pintado, S. Viti, arXiv:0911.2673 [ps, pdf, other]
Comments: 32 pages, 4 figures, Published in ApJ
Journal-ref: 2009 ApJ 706 1323-1330

Origin(s) of the Highly Ionized High-Velocity Clouds Based on Their Distances
N. Lehner, J. C. Howk, arXiv:0911.2732 [ps, pdf, other]
Comments: Submitted to the ApJ Letters

Black Holes and AGN

Quasar Outflow Contribution to AGN Feedback: Observations of QSO SDSS J0838+2955
Maxwell Moe, Nahum Arav, Manuel A. Bautista, Kirk T. Korista, arXiv:0911.3332 [ps, pdf, other]
Comments: 28 pages, 7 figures, 4 tables, published in Astrophysical Journal
Journal-ref: 2009 ApJ 706 525-534

Their full abstract: "We present a detailed analysis of the Astrophysical Research Consortium 3.5 m telescope spectrum of QSO SDSS J0838+2955. The object shows three broad absorption line (BAL) systems at 22,000, 13,000, and 4900 km s^-1 blueshifted from the systemic redshift of z=2.043. Of particular interest is the lowest velocity system that displays absorption from low-ionization species such as Mg II, Al II, Si II, Si II*, Fe II and Fe II*. Accurate column densities were measured for all transitions in this lowest velocity BAL using an inhomogeneous absorber model. The ratio of column densities of Si II* and Fe II* with respect to their ground states gave an electron number density of log n_e (cm^-3) = 3.75 +/- 0.22 for the outflow. Photoionization modeling with careful regards to chemical abundances and the incident spectral energy distribution predicts an ionization parameter of log U_H = -1.93 +/- 0.21 and a hydrogen column density of log N_H (cm^-2) = 20.80 +/- 0.28. This places the outflow at 3.3+1.5-1.0 kpc from the central AGN. Assuming that the fraction of solid angle subtended by the outflow is 0.2, these values yield a kinetic luminosity of (4.5+3.1-1.8) x 10^45 erg s^-1, which is (1.4+1.1-0.6)% the bolometric luminosity of the QSO itself. Such large kinetic luminosity suggests that QSO outflows are a major contributor to AGN feedback mechanisms."

Numerical Astrophysics and Hydrodynamics

Turbulence modeling and the physics of the intra-cluster medium
L. Iapichino, A. Maier, W. Schmidt, J. C. Niemeyer, arXiv:0911.2629 [ps, pdf, other]
Comments: To appear in the proceedings of the "Invisible Universe International Conference"

Characterizing Magnetohydrodynamic Turbulence in the Small Magellanic Cloud
Blakesley Burkhart, Snezana Stanimirovic, Alex Lazarian, Grzegorz Kowal, arXiv:0911.3652 [ps, pdf, other]

Stars, Supernovae and Planets

A Feature Movie of SiO Emission 20-100 AU from the Massive Young Stellar Object Orion Source I
L. D. Matthews, L. J. Greenhill, C. Goddi, C. J. Chandler, E. M. L. Humphreys, M. Kunz, rXiv:0911.2473 [pdf, other]

Comments: Accepted to ApJ (January 2010); a full resolution version along with two accompanying GIF movies may be found at this http URL

An Unusually Fast-Evolving Supernova
Dovi Poznanski, Ryan Chornock, Peter E. Nugent, Joshua S. Bloom, Mohan Ganeshalingam, Douglas C. Leonard, Weidong Li, Rollin C. Thomas, arXiv:0911.2699 [pdf, other]
Comments: Science in press, first published online on Nov 5, 2009 in Science Express. Includes supporting online materia

The low-mass Initial Mass Function in the 30 Doradus starburst cluster
M. Andersen, H. Zinnecker, A. Moneti, M. J. McCaughrean, B. Brandl, W. Brandner, G. Meylan, D. Hunter, arXiv:0911.2755 [ps, pdf, other]
Comments: Accepted in ApJ. Abstract abridged

How Common are Extrasolar, Late Heavy Bombardments?
Mark Booth, Mark C. Wyatt, Alessandro Morbidelli, Amaya Moro-Martín, Harold F. Levison, arXiv:0911.3271 [ps, pdf, other]
Comments: 2 pages, 1 figure. Contribution to the conference proceedings for 'Pathways towards habitable planets'

Other

A Vigorous Explorer Program
Martin Elvis, et al, arXiv:0911.3383 [pdf]
Comments: 18 pages, no figures. An Activities/Program White Paper submitted to the Astro2010 NAS/NRC Decadal Review of Astronomy and Astrophysics

Interesting Astrophysics: Nov 09 to 13

2009-11-13T08:56:00.002-05:00

A mixed set of interesting preprints this week, with a strong emphasis on winds, either supernova-driven winds starbursts at high redshift (Kornei et al) or possibly from the center of our own galaxy (Law), and even outflows driven by black holes (King).

A second theme with a strong showing of interesting papers is astrobiology: the biological effects of radiation from "normal" stellar processes on the main sequence (Cuntz et al) or from Gamma ray bursts (Martin et al).

Galaxies and Starbursts

Morphologies of local Lyman break galaxy analogs II: A Comparison with galaxies at z=2-4 in ACS and WFC3 images of the Hubble Ultra Deep Field
R.A. Overzier, T.M. Heckman, D. Schiminovich, A. Basu-Zych, T. Goncalves, D.C. Martin, R.M. Rich, arXiv:0911.1279 [ps, pdf, other]

Comments: Submitted to ApJ (14 pages, 7 figures). For a high-resolution colour version and background material, see this http URL

The Relationship Between Stellar Populations and Lyman Alpha Emission in Lyman Break Galaxies
Katherine A. Kornei, Alice E. Shapley, Dawn K. Erb, Charles C. Steidel, Naveen A. Reddy, Max Pettini, Milan Bogosavljevic, arXiv:0911.2000 [ps, pdf, other]
Comments: 24 pages, 15 figures, submitted to ApJ

From their abstract: "We accordingly conclude that, within the LBG sample, objects with strong Lya emission represent a later stage of galaxy evolution in which supernovae-induced outflows have reduced the dust covering fraction. We also examined the hypothesis that the attenuation of Lya photons is lower than that of the continuum, as proposed by some, but found no evidence to support this picture."

A Multiwavelength View of a Mass Outflow from the Galactic Center
C. J. Law, arXiv:0911.2061 [pdf, other]
Comments: Accepted to ApJ. 15 pages, 8 (compressed) figures

From the abstract: "I compare the physical conditions of the GC lobe to several models and find best agreement with the canonical starburst outflow model. The formation of the GC lobe is consistent with the currently observed pressure and star formation rate in the central tens of parsecs of our Galaxy. Outflows of this scale are more typical of dwarf galaxies and would not be easily detected in nearby spiral galaxies. Thus, the existence of such an outflow in our own Galaxy may indicate that it is relatively common phenomenon in the nuclei of spiral galaxies."

Black Holes and AGN

Discovery of a 115 Day Orbital Period in the Ultraluminous X-ray Source NGC 5408 X-1
Tod E. Strohmayer, arXiv:0911.1339 [ps, pdf, other]
Comments: Accepted for Publication in the Astrophysical Journal Letters

Black Hole Outflows
A.R. King, arXiv:0911.1639 [ps, pdf, other]
Comments: MNRAS, to appear

Numerical Astrophyics

Generating on-the-fly large samples of theoretical spectra through N-dimensional grid
Ching-Wa Yip, arXiv:0911.1280 [ps, pdf, other]
Comments: 7 pages, 5 figures, 1 table. Accepted for publication in AJ

Stars, Supernovae and Planets

Biological Damage due to Photospheric, Chromospheric and Flare Radiation in the Environments of Main-Sequence Stars
M. Cuntz, E. F. Guinan, R. L. Kurucz, arXiv:0911.1982 [ps, pdf, other]
Comments: 8 pages, 4 figues, Planetary Systems as Potential Sites for Life, Invited Paper, IAU Symposium 264, eds. A. Kosovichev et al. (San Francisco: Astr. Soc. Pac.), in press

Effects of Gamma Ray Bursts in Earth Biosphere
Osmel Martin, Rolando Cardenas, Mayrene Guimaraes, Liuba Penate, Jorge Horvath, Douglas Galante, arXiv:0911.2196 [pdf, other]
Comments: Accepted for publication in Astrophysics & Space Science

Interesting Astrophysics: Nov 02 to Nov 06

2009-11-06T09:05:00.002-05:00

Of particular note this week are Crighton et al (who suggest a particular case of intergalactic metal line absorption can be associated with a z=0.2272 galaxy polluting a region ~200 kpc in radius), Bertone et al (metal line cooling from the IGM predicted in the OWLS simulations) Risaliti & Elvis (a line driven model for AGN winds), and Bond et al (terrestrial planet formation models that correctly predict the observed elemental abundances also predict that terrestrial planets form wet and do not need significant water delivery from comets).

Galaxies and Starbursts

Searching for Evidence of Energetic Feedback in Distant Galaxies: A Galaxy Wide Outflow in a z~2 Ultraluminous Infrared Galaxy
D.M. Alexander, A.M. Swinbank, I. Smail, R. McDermid, N. Nesvadba, arXiv:0911.0014 [ps, pdf, other]
Comments: 10 pages, 5 figures, 1 table. Resubmitted to MNRAS after taking account of referees feedback

Galaxies at Redshift ~0.5 Around Three Closely Spaced Quasar Sightlines
Neil H. M. Crighton, Simon L. Morris, Jill Bechtold, Robert A. Crain, Buell T. Jannuzi, Allen Shone, Tom Theuns, arXiv:0911.0368 [pdf, other]
Comments: 45 pages, 21 figures. Accepted by MNRAS

From their abstract: "We identify a galaxy at z=0.2272 with associated metal absorption in two sightlines, each 200 kpc away. By constraining the star formation history of the galaxy, we show the gas causing this metal absorption may have been enriched and ejected by the galaxy during a burst of star formation 2 Gyr ago."

Enhanced Dense Gas Fraction in Ultra-Luminous Infrared Galaxies
S. Juneau, D. T. Narayanan, J. Moustakas, Y. L. Shirley, R. S. Bussmann, R. C. Kennicutt Jr, P. A. Vanden Bout, arXiv:0911.0413 [ps, pdf, other]
Comments: 20 pages, 10 figures. To be published in The Astrophysical Journal (accepted)

Black Holes and AGN

Comparison between the Luminosity functions of X-ray and [OIII] selected AGN
I. Georgantopoulos, A. Akylas, arXiv:0911.0102 [ps, pdf, other]

Comments: 7 pages to appear in Astronomy & Astrophysics

A non-hydrodynamical model for acceleration of line-driven winds in Active Galactic Nuclei
G. Risaliti, M. Elvis, arXiv:0911.0958 [ps, pdf, other]
Comments: 15 pages, 9 figures. Accepted for publication in Astronomy & Astrophysics

Numerical Astrophysics

Metal-line emission from the warm-hot intergalactic medium: I. Soft X-rays
Serena Bertone, Joop Schaye, Claudio Dalla Vecchia, C.M. Booth, Tom Theuns, Robert P.C. Wiersma, arXiv:0910.5723 [ps, pdf, other]

The Enrichment of Intergalactic Medium With Adiabatic Feedback I: Metal Cooling and Metal Diffusion
Sijing Shen, James Wadsley, Gregory Stinson, arXiv:0910.5956 [ps, pdf, other]
Comments: 16 pages, 11 figures, submitted to MNRAS

Ram-pressure stripping of halo gas in disc galaxies: implications for galactic star formation in different environments
Kenji Bekki, 2009, MNRAS, 399, 2221
Full Text: HTML, PDF (Size: 4409K)

The impact of feedback on the low redshift Intergalactic Medium
Luca Tornatore, Stefano Borgani, Matteo Viel, Volker Springel, arXiv:0911.0699 [ps, pdf, other]
Comments: revised version after referee's comments

Stars, Supernovae and Planets

Making the Earth: Combining Dynamics and Chemistry in the Solar System
Jade C. Bond, Dante S. Lauretta, David P. O'Brien, arXiv:0911.0426 [ps, pdf, other]
Comments: 61 pages (including online material), 12 figures (7 in paper, 5 online). Accepted to Icarus

From their abstract: "Bulk elemental abundances based on disk equilibrium studies have been determined for the simulated terrestrial planets of O'Brien et al. (2006). These abundances are in excellent agreement with observed planetary values, indicating that the models of O'Brien et al. (2006) are successfully producing planets comparable to those of the Solar System in terms of both their dynamical and chemical properties. Significant amounts of water are accreted in the present simulations, implying that the terrestrial planets form "wet" and do not need significant water delivery from other sources. Under the assumption of equilibrium controlled chemistry, the biogenic species N and C still need to be delivered to the Earth as they are not accreted in significant proportions during the formation process."

Interesting Astrophysics: 26 Oct to 30 Oct

2009-10-30T10:03:00.002-04:00

Galaxies and Starbursts

A New Empirical Method to Infer the Starburst History of the Universe from Local Galaxy Properties
Philip F. Hopkins, Lars Hernquist, arXiv:0910.4582 [ps, pdf, other]
Comments: 21 pages, 8 figures, accepted to MNRAS

Constraining the initial mass function of stars in the Galactic Centre
Ulf Loeckmann, Holger Baumgardt, Pavel Kroupa, arXiv:0910.4960 [ps, pdf, other]
Comments: MNRAS, accepted, 8 pages, 4 figures

HI Selected Galaxies in the Sloan Digital Sky Survey I: Optical Data
Andrew A. West, Diego A. Garcia-Appadoo, Julianne J. Dalcanton, Mike J. Disney, Constance M. Rockosi, Zeljko Ivezic, Misty C. Bentz, J. Brinkmann, arXiv:0910.4965 [ps, pdf, other]
Comments: 14 pages, 8 Figures, accepted for publication in AJ. Complete tables will be available in the AJ electronic version and on the Vizier site

HI Selected Galaxies in the Sloan Digital Sky Survey II: The Colors of Gas-Rich Galaxies
Andrew A. West, Diego A. Garcia-Appadoo, Julianne J. Dalcanton, Mike J. Disney, Constance R. Rockosi, Zeljko Ivezic, arXiv:0910.4966 [ps, pdf, other]
Comments: 12 pages, 16 figures, published in AJ (138, 796); replaced Figure 16 with higher resolution version
Journal-ref: West et al. 2009, AJ, 138, 796

Numerical Astrophysics

Adaptive Mesh Fluid Simulations on GPU
Peng Wang, Tom Abel, Ralf Kaehler, arXiv:0910.5547 [ps, pdf, other]
Comments: Submitted to New Astronomy

CUDA & MPI, with what sounds like the ZEUS MHD scheme. Hardly surprising, but nice to see some effort going into exploring the use of GPU computing with hydro codes.

Stars, Supernovae and Planets

Evolution of supermassive stars as a pathway to black hole formation
Mitchell C. Begelman, arXiv:0910.4398 [ps, pdf, other]
Comments: 10 pages, 5 figures, to appear in Monthly Notices of the Royal Astronomical Society

X-ray observations of classical novae. Theoretical implications
M. Hernanz, G. Sala, arXiv:0910.4607 [ps, pdf, other]
Comments: 6 pages, review paper accepted for publication in Astronomische Nachrichten

The Nature and Nurture of Star Clusters
Bruce G. Elmegreen, arXiv:0910.4638 [ps, pdf, other]
Comments: to be published in IAUS266: Star Clusters Basic Galactic Building Blocks Throughout Time And Space, eds. Richard de Grijs and Jacques Lepine, Cambridge University Press, 11 pages

Nuclear Star Clusters
Torsten Boeker, arXiv:0910.4863 [ps, pdf, other]
Comments: invited talk at IAU Symp. 266 "Star Clusters: Galactic Building Blocks through Space and Time"

Interesting Astrophysics: Oct 12 to Oct 23

2009-10-23T08:37:00.002-04:00

This edition of Interesting Astrophysics spans an even wide range of topics than normal, from C IV in the IGM (D'Odorico et al), X-ray emission from galaxies (Laird et al, Pietsch), a variety of supernova-related preprints, to AGN feedback/outflows and other topics I've not mentioned.

Galaxies and Starbursts

An Anisotropic Propagation Model for Galactic Cosmic Rays
Iris Gebauer, Wim de Boer, arXiv:0910.2027 [ps, pdf, other]
Comments: 19 pages, 19 figures, submitted to A&A

The rise of the C IV mass density at z<2.5
Valentina D'Odorico, Francesco Calura, Stefano Cristiani, Matteo Viel, arXiv:0910.2126 [ps, pdf, other]
Comments: Paper accepted by MNRAS. The parameters of the C IV line fitting will be available in electronic format

The radial distribution of core-collapse supernovae in spiral host galaxies
A. A. Hakobyan, G. A. Mamon, A. R. Petrosian, D. Kunth, M. Turatto, arXiv:0910.1801 [ps, pdf, other]
Comments: 10 pages, 6 figures, 5 tables. Astronomy & Astrophysics, in press

On the X-ray properties of submm-selected galaxies
Elise S. Laird, Kirpal Nandra, Alexandra Pope, Douglas Scott, arXiv:0910.2464 [ps, pdf, other]
Comments: 12 pages, 5 figures, accepted for publication in MNRAS

X-ray emission from optical novae in M 31
W. Pietsch, arXiv:0910.3865 [ps, pdf, other]
Comments: 6 pages, 4 figures, accepted for publication in Aston.Nachr

Bars in Starbursts and AGNs -- A Quantitative Reexamination
Lei Hao, Shardha Jogee, Fabio D. Barazza, Irina Marinova, Juntai Shen, arXiv:0910.3960 [ps, pdf, other]
Comments: 8 pages, 3 figures, to be published in "Galaxy Evolution: Emerging Insights and Future Challenges", ed. S. Jogee et al., Astron. Soc. Pacific, 2009

From their abstract: "We find that AGN and star-forming galaxies have similar optical bar fractions, 47% and 50%, respectively. Both bar fractions are higher than that in inactive galaxies (29%)."

Extragalactic CS survey
E. Bayet, R. Aladro, S. Martin, S. Viti, J. Martin-Pintado, arXiv:0910.4282 [pdf, other]
Comments: 17 pages, 16 figures, 3 tables, Accepted to ApJ

From the abstract: "We present a coherent and homogeneous multi-line study of the CS molecule in nearby (D$<$10Mpc) galaxies. We include, from the literature, all the available observations from the $J=1-0$ to the $J=7-6$ transitions towards NGC 253, NGC 1068, IC 342, Henize~2-10, M~82, the Antennae Galaxies and M~83."

Black Holes and AGN

Feeding and Feedback in nearby AGN from Integral Field Spectroscopy
Thaisa Storchi-Bergmann, arXiv:0910.3234 [ps, pdf, other]
Comments: 4 pages, 2 figures, to appear in the proceedings of the conference "The Monster's Fiery Breath", eds. Sebastian Heinz and Eric Wilcots

From the abstract: "The ionized gas, on the other hand, traces the AGN feedback. Its
kinematics shows two components: (1) one originating in the plane, and
dominated by circular rotation; (2) another outflowing along the Narrow-Line
Region (NLR) whose flux distribution and kinematics frequently correlate with
structures seen in radio maps. Mass outflow rates along the NLR range from
10^-2 to 1 M_sun yr^-1, corresponding to 10-100 times the accretion rate to the
AGN, indicating that most of the NLR gas mass has been entrained from the
galaxy plane. The average kinetic power of the NLR outflows is ~10^-4 times the
bolometric luminosity.
"

AGN Feedback: Does it work?
Smita Mathur, Rebecca Stoll, Yair Krongold, Fabrizio Nicastro, Nancy Brickhouse, Martin Elvis, arXiv:0910.3691 [ps, pdf, other]
Comments: to appear in proceedings of the conference "The Monster's Fiery Breath: Feedback in Galaxies, Groups, and Clusters", June 2009, Madison, WI, Eds. S. Heinz & E. Wilcots

Interstellar Medium

PAH processing in interstellar shocks
E. R. Micelotta, A. P. Jones, A. G. G. M. Tielens, arXiv:0910.2461 [ps, pdf, other]
Comments: 21 pages, 11 figures, accepted for publication in Astronomy and Astrophysics

VLT/FLAMES-ARGUS observations of stellar wind--ISM cloud interactions in NGC 6357
M.S. Westmoquette, J.D. Slavin, L.J. Smith, J.S. Gallagher III, arXiv:0910.4191 [ps, pdf, other]
Comments: 9 pages, 5 figures (3 colour). Accepted for publication in MNRAS

Stars, Supernovae and Planets

The rebrightening of planetary nebulae through ISM interaction

C J Wareing, arXiv:0910.2200 [ps, pdf, other]

Comments: Review paper accepted to PASA. 8 pages, 5 figures. High resolution images available from the author

Stellar Feedback in Molecular Clouds and its Influence on the Mass Function of Young Star Clusters
S. Michael Fall, Mark R. Krumholz, Christopher D. Matzner, arXiv:0910.2238 [ps, pdf, other]
Comments: 5 pages, 2 figures, emulateapj format, submitted to ApJL

Typing Supernova Remnants Using X-ray Line Emission Morphologies
Laura A. Lopez, Enrico Ramirez-Ruiz, Carles Badenes, Daniela Huppenkothen, Tesla E. Jeltema, David A. Pooley, arXiv:0910.3208 [ps, pdf, other]
Comments: 4 pages, 1 figure, accepted for publication in ApJL

Line-of-sight Shell Structure of the Cygnus Loop
Hiroyuki Uchida, Hiroshi Tsunemi, Satoru Katsuda, Masashi Kimura, Hiroko Kosugi, Hiroaki Takahashi, arXiv:0910.3731 [ps, pdf, other]
Comments: 8 pages, 7 figures, accepted for publication in ApJ
Journal-ref: Astrophysical Journal 705 (2009) 1152-1159

Other

FISH: A 3D parallel MHD code for astrophysical applications
R. Kaeppeli, S. C. Whitehouse, S. Scheidegger, U.-L. Pen, M. Liebendoerfer, arXiv:0910.2854 [ps, pdf, other]
Comments: 27 pages, 11 figures

Astrometry.net: Blind astrometric calibration of arbitrary astronomical images
Dustin Lang, David W. Hogg, Keir Mierle, Michael Blanton, Sam Roweis, arXiv:0910.2233 [pdf, other]
Comments: submitted to AJ

A very cool idea!

Interesting Astrophysics: 05 Oct to 09 Oct

2009-10-09T08:58:00.002-04:00

A mixed bag of interesting preprints this week. Of note are local analogs of the Lyman Break Galaxies (Overzier et al), the radio-FIR correlation at high z (Lacki & Thompson), and a possible optical counterpart to an intermediate mass black hole candidate (Soria et al).

Galaxies and Starbursts

Local Lyman Break Galaxy Analogs: The Impact of Massive Star-forming Clumps on the Interstellar Medium and the Global Structure of Young, Forming Galaxies
R.A. Overzier, T.M. Heckman, C. Tremonti, L. Armus, A. Basu-Zych, T. Goncalves, R.M. Rich, D.C. Martin, A. Ptak, D. Schiminovich, H.C. Ford, B. Madore, M. Seibert, arXiv:0910.1352 [ps, pdf, other]

Comments: The Astrophysical Journal, In Press (22 pages, 16 figures). For the full version with high-resolution colour figures, see: this http URL

Stationary models for the extra-planar gas in disc galaxies
F. Marinacci, F. Fraternali, L. Ciotti, C. Nipoti, arXiv:0910.0404 [ps, pdf, other]
Comments: 14 pages, 7 figures, accepted for pubblication in MNRAS

A cloudy halo model.

The Physics of the FIR-Radio Correlation: II. Synchrotron Emission as a Star-Formation Tracer in High-Redshift Galaxies
Brian C. Lacki, Todd A. Thompson, arXiv:0910.0478 [ps, pdf, other]
Comments: Submitted to ApJ

The fundamental gas depletion and stellar-mass buildup times of star forming galaxies
Jan Pflamm-Altenburg, Pavel Kroupa, arXiv:0910.1089 [ps, pdf, other]
Comments: accepted for publication in ApJ

The WMAP haze from the Galactic Center region due to massive star explosions and a reduced cosmic ray scale height
Peter L. Biermann, Julia K. Becker, Gabriel Caceres, Athina Meli, Eun-Suk Seo, Todor Stanev, arXiv:0910.1197 [ps, pdf, other]
Comments: 10 pages

Black Holes and AGN

The Activity of the Neighbours of AGN and Starburst Galaxies: Towards an evolutionary sequence of AGN activity
E.Koulouridis, M.Plionis, V.Chavushyan, D.Dultzin, Y.Krongold, I.Georgantopoulos, C.Goudis, arXiv:0910.1355 [ps, pdf, other]
Comments: 50 pages, 5 figures, 41 spectra

Discovery of an optical counterpart to the hyperluminous X-ray source in ESO 243-49
Roberto Soria, George K. T. Hau, Alister W. Graham, Albert K. H. Kong, N. Paul M. Kuin, I-Hui Li, Ji-Feng Liu, Kinwah Wu, arXiv:0910.1356 [ps, pdf, other]
Comments: 5 pages, submitted to MNRAS Letters. Contact R Soria for higher-resolution figures

Theoretical and Numerical Astrophysics, including Cosmology

Pressure Support vs. Thermal Broadening in the Lyman-alpha Forest II: Effects of the Equation of State on Transverse Structure
Molly S. Peeples, David H. Weinberg, Romeel Davé, Mark A. Fardal, Neal Katz, arXiv:0910.0250 [ps, pdf, other]
Comments: 11 figures, submitted to MNRAS

Stars, Supernovae and Planets

Ionized Gas Towards Molecular Clumps: Physical Properties of Massive Star Forming Regions
Katharine G. Johnston, Debra S. Shepherd, James E. Aguirre, Miranda K. Dunham, Erik Rosolowsky, Kenneth Wood, arXiv:0910.0251 [ps, pdf, other]
Comments: 67 pages, 16 figures, 8 tables, accepted for publication in ApJ

From their abstract: "For clumps with associated ionized gas, the combined mass of the ionizing massive stars is compared to the clump masses to provide an estimate of the instantaneous star formation efficiency. These values range from a few percent to 25%, and have an average of 7 +/- 8%. We also find a correlation between the clump mass and the mass of the ionizing massive stars within it, which is consistent with a power law. This result is comparable to the prediction of star formation by competitive accretion that a power law relationship exists between the mass of the most massive star in a cluster and the total mass of the remaining stars."

HuffPo lunacy

2009-10-08T18:32:00.008-04:00

The Huffington Post has a certain reputation for allowing (perhaps it would be more accurate to say promoting) quacks, vaccine denialists, conspiracy theorists and other superstitious wackery, but the example that follows is impressively moronic even by HuffPo standards.

As Tariq Malik at Space.com reports regarding NASA's LCROSS lunar impact (emphasis mine):

NASA's LCROSS mission will slam a spacecraft and an empty rocket stage into the moon's south pole Friday morning at 7:31 a.m. EDT (1131 GMT) in a search for water ice buried in the perpetual shadows of lunar craters.
Scientists are eagerly awaiting the LCROSS crashes and hope they'll provide a definitive answer on whether lunar water ice could be used to support future astronauts on the moon. But at least one person — novelist and screenwriter Amy Ephron — has spoken out against the $79 million mission on her Huffington Post blog and launched a Twitter campaign ("helpsavethemoon") to save the moon from future onslaught.

"I'm not a big fan of explosions, anyway. In Iraq or Afghanistan or the South Pole of the Moon. But who does have a territorial prerogative there?" Ephron wrote. "Who has jurisdiction? Who has the right to say that it's okay to blow up a crater on the moon?"

Apparently, Mother Nature does. The moon is covered in craters, with new ones like those to be created by the LCROSS probes popping up all the time by meteorites that pummel the lunar surface.

"The image of this impact, what we're doing with the moon, is something that occurs naturally four times a month on the moon, whether we're there or not," LCROSS principal investigator Tony Colaprete told reporters Thursday.

I love Malik and Colaprete's understated but effectively utter refutation of Ephron's deliberately ignorant rant. Keep it up!

New mega ring around Saturn discovered using Spitzer

2009-10-08T09:15:00.003-04:00

Infrared observations using the Spitzer Space Telescope, published by Verbiscer et al (2009, Nature), have revealed the largest known ring around Saturn, an annulus of very tenuous material extending between 6 million and 18 million kilometers from Saturn, and tilted by 27 degree from the plane of the traditional rings (which only extend out to ~240,000 km).

The material in the new ring comes from the battered and cratered moon Phoebe. Of more interest, this new dust ring explains why the leading side of Iapetus is so much darker than the rest of it - the dark front surface of Iapetus is material from the ring swept up by Iapetus as it orbits at the inner edge of the new ring.

In truth a link between the dark front of Iapetus and Phoebe has been suspected before now, as the composition of the dark material is very similar to that of Phoebe based on near IR spectroscopy with Cassini. What the Spitzer observations reveal is the presence of the dust ring and hence the mechanism of material transfer from Phoebe to Iapetus.

Although the ring is physically huge, with a volume of ~5e21 km^3 (this is my BOTE calculation. As far as I can tell Verbiscer et al do not quote a volume), it is incredibly tenuous, and if all the material within it were collected back into one place it would possibly only occupy ~ 1 km^3 of rock, i.e. the volume of a crater on Phoebe.

The other interesting thing is that the material migrates inwards under the influence of radiation pressure. From Verbiscer et al:

On long timescales, collisions and inward transport become important. Collision with Phoebe, the dominant loss mechanism for particles larger than several centimetres in size, takes on the order of 10¹⁰ years. Re-radiation of absorbed sunlight exerts an asymmetric force on dust grains, causing them to spiral in towards Saturn with a characteristic timescale of 1.5 10⁵r_g years where r_g is the particle radius in micrometres. This force brings all centimetre-sized and smaller material to Iapetus and Titan unless mutual particle collisions occur first. The rate of mutual collisions depends on the size distribution of the ring particles and optical depth; if the ring were comprised entirely of 10 m grains, then the collisional timescale would be tens of millions of years, which is comparable to the inward drag timescale. Most material from 10 m to centimetres in size ultimately hits Iapetus, with smaller percentages striking Hyperion and Titan³.

References:

Verbiscer, A., Skrutskie, M., & Hamilton, D. (2009). Saturn's largest ring Nature DOI: 10.1038/nature08515

BBC article published by Jonathan Amos. 2009/10/08 (the source of the nice graphic shown above).

Spitzer press release, 2009/10/06.

Interesting Astrophysics: Sep 28 to Oct 02

2009-10-02T09:10:00.002-04:00

A mixed bag of preprints this week. From my personal perspective I'd say the Marchili et al paper on M82' SN2008iz and Acero et al's paper on a gamma ray detection of NGC 253 are the most interesting.

Galaxies and Starbursts

The radio lightcurve of SN 2008iz in M82 revealed by Urumqi observations
N. Marchili, I. Marti-Vidal, A. Brunthaler, T.P. Krichbaum, P. Mueller, X. Liu, H.-G. Song, U. Bach, R. Beswick, J.A. Zensus, arXiv:0909.5535 [ps, pdf, other]
Comments: 7 pages, 3 figures. Accepted for publication in A & A

Detection of Gamma Rays From a Starburst Galaxy
The HESS Collaboration: F. Acero, et al, arXiv:0909.4651 [ps, pdf, other]

Comments: 24 pages, 8 figures, published in Science Express, see: this http URL

Reported H.E.S.S. gamma ray detection of NGC 253, F()>220 GeV) = [5.5 +/- 1.0(stat) +/- 2.8 (sys)] times 10-13 cm-2 s-1. Much of the interpretation is done under the assumption that all the activity is due to the starburst, and NOT related to any AGN, which I'm not personally sure is a robust assumption. Still its an interesting mini-paper.

Star Formation Histories within the Antennae Galaxies (Arp 244)
Hong-Xin Zhang, Yu Gao, Xu Kong, arXiv:0909.5186 [ps, pdf, other]
Comments: 13 pages, 7 figures, accepted by MNRAS

How ubiquitous are massive starbursts in interacting galaxies?
P. Di Matteo, F. Bournaud, M. Martig, F. Combes, A.-L. Melchior, B. Semelin, arXiv:0909.5192 [ps, pdf, other]
Comments: 4 pages, Proceedings of the conference "Galaxies in isolation: exploring Nature vs Nurture" (May 2009, Granada, Spain)

Comparison of H-alpha and UV Star Formation Rates in the Local Volume: Systematic Discrepancies for Dwarf Galaxies
Janice C. Lee, Armando Gil de Paz, Christy Tremonti, Robert C. Kennicutt Jr., Samir Salim, Matthew Bothwell, Daniela Calzetti, Julianne Dalcanton, Daniel Dale, Chad Engelbracht, Jose G. Funes S.J., Benjamin Johnson, Shoko Sakai, Evan Skillman, Liese van Zee, Fabian Walter, Daniel Weisz, arXiv:0909.5205 [ps, pdf, other]
Comments: 29 pages, 10 figures, 2 tables, accepted for publication in ApJ

The Far-Infrared--Radio Correlation at High Redshifts: Physical Considerations and Prospects for the Square Kilometer Array
Eric J. Murphy, arXiv:0910.0011 [ps, pdf, other]
Comments: 16 pages, 8 figures, accepted for publication in ApJ

What stellar populations can tell us about the evolution of the mass-metallicity relation in SDSS galaxies
N. Vale Asari, G. Stasinska, R. Cid Fernandes, J. M. Gomes, M. Schlickmann, A. Mateus, W. Schoenell, arXiv:0910.0224 [ps, pdf, other]
Comments: To appear in the proceedings of IAU symposium 262, 'Stellar Populations - Planning for the Next Decade'

From their abstract: "Our results suggest that the M-Z relation for galaxies with present-day stellar masses down to 10^10 solar masses is mainly driven by the star formation history and not by inflows or outflows." This strikes me as a bit odd for a major conclusion, as pretty much everyone agrees that M-Z is dominated by the SF history... the real argument if M-yeff, and the trends suggestive of outflow really kick in for galaxies *below* 10^10.5 solar masses.

Theoretical Cosmology

Can galaxy outflows and re-accretion produce the downsizing in specific star formation rate of late-type galaxies?
C. Firmani, V. Avila-Reese, A. Rodriguez-Puebla, arXiv:0909.5188 [ps, pdf, other]
Comments: 11 pages, 4 figures. Comments are welcome. Submitted to MNRAS

The physics driving the cosmic star formation history
Joop Schaye, Claudio Dalla Vecchia, C. M. Booth, Robert P. C. Wiersma, Tom Theuns, Marcel R. Haas, Serena Bertone, Alan R. Duffy, I. G. McCarthy, Freeke van de Voort, arXiv:0909.5196 [ps, pdf, other]
Comments: Submitted to MNRAS, 27 pages and 18 figures

Numerical Astrophysics

A new radiative cooling curve based on an up to date plasma emission code
K.M. Schure, D. Kosenko, J.S. Kaastra, R. Keppens, J. Vink, arXiv:0909.5204 [ps, pdf, other]

Comments: 11 pages, 6 figures. Accepted for publication in A&A. Tables in text format online available at this http URL

Collisional ionisation equilibrium cooling, valid above 10⁴ K.. Seems pretty straightforward.

Numerical Implementation of Streaming Down the Gradient: Application to Fluid Modeling of Cosmic Rays
Prateek Sharma, Phillip Colella, Daniel F. Martin, arXiv:0909.5426 [ps, pdf, other]
Comments: submitted to SIAM J. of Scient. Comp.; 15 pages, 9 figs.; comments welcome

Stars, Supernovae and Planets

Stellar models: firm evidence, open questions and future developments
Santi Cassisi, arXiv:0909.4629 [ps, pdf, other]
Comments: 10 pages, 3 figures, Keynote review talk at the IAU Symp. 262 "Stellar Populations - Planning the Next Decade" of the XXVIIth IAU General Assembly held in Rio de Janeiro (Brazil), Proceeding eds. G. Bruzual & S. Charlot

Chandra observation of Cepheus A: The diffuse emission of HH 168 resolved
P. C. Schneider, H. M. Guenther, J. H. M. M. Schmitt, arXiv:0909.5326 [ps, pdf, other]
Comments: 8 pages, 5 figures, accepted for publication in A&A

Core collapse supernovae and starbursts
Miguel A. Perez-Torres, arXiv:0909.5578 [ps, pdf, other]
Comments: Proceedings of the 8th international e-VLBI Workshop, accepted for publication, 6 pages, 1 figure,

Brian Switek reviews the Templeton Foundation's "Test of Faith" DVD series

2009-10-01T13:56:00.001-04:00

Brian Switek has a characteristically thoughtful review of the Templeton Foundation's DVD miniseries "Test of Faith" on his blog. As Brian is not one of those evil "divisive" (or worse: "uncivil") atheists like Dawkins, Coyne or PZ Myers I'd hope that his critique is not dismissed out of hand by pro-religion accommodationists.

Unfortunately for an organization that claims to represent a serious, sober and moderate vision of (some form of) religion and science not in being in conflict, the DVDs engage in much the same sort of God-of-the-gaps teleology and straw-man argumentation that creationists normally engage in.

Nor does the Templeton Foundation's vision of religion sound particularly deist or ecumenical. Brian writes:

I would not have been so aggravated with the program if it presented scientists who said something akin to "I am a Christian/Muslim/Buddhist/Pastafarian/&c. I believe [insert belief system here] on the basis of faith, and I feel what I have come to understand about the nature of the universe is consistent with the faith I practice. Rather than make nature conform to my beliefs, however, I would rather understand the world as it is. If it turns out to be inconsistent with my faith then I will have to question what I believe." I could at least respect that. Instead the Test of Faith series trots out scientist after scientist who believe that they have some special glimmer or proof of God in nature; it is going at the whole thing backwards. The impression the series gives is that the natural world justifies and supports a particular religion, Christianity, rather than stating that some liberal forms of that religion could accept the science of evolution. (Whether evolution is reconcilable with religion depends on what brand religion we're talking about.)

And people wonder why many scientists have little or no respect for the Templeton Foundation?

PS: The 'physicist Katherine Blundell [who] says that there are "truths" in the universe that science does not detect' (*) mentioned is most probably the Oxford astronomer Katherine Blundell, as she is associated with some organization called The Faraday Institute For Science and Religion.

* Oh really. How do you know?

Interesting Astrophysics: Sep 21 to Sep 25

2009-09-25T09:41:00.002-04:00

A interesting week. Of particular note: Radio observation of young SNe/SNRs in Arp 299 (NGC 3690+IC 694) by Ulvestad and also Perez-Torres et al; empirical measures of gas consumption in galaxies by Bauermeister et al versus simulated gas accretion by Kereš et al (which makes galaxies too massive); YACRDWM (yet another cosmic ray driven wind model), this time by Samui et al; and estimates of the delay time for prompt Type Ia supernovae (Raskin et al)

Galaxies and Starbursts

Radio Emission from Young Supernovae and Supernova Remnants in Arp 299
James S. Ulvestad, arXiv:0909.3534 [ps, pdf, other]
Comments: Astronomical Journal, in press, December 2009 issue

Arp 299 = NGC 3690 + IC 694. Finds 30 point-like radio sources in the two nuclei. Also gives estimated sizes of the two regions where the young SNe/SNRs are found.

An extremely prolific supernova factory in the buried nucleus of the starburst galaxy IC 694
M.A. Perez-Torres, C. Romero-Canizales, A. Alberdi, A. Polatidis, arXiv:0909.3959 [ps, pdf, other]
Comments: Under revision by A&A, 6 pages, 2 figures

Makes a number of rather strong claims...

The Gas Consumption History to z ~ 4
Amber Bauermeister, Leo Blitz, Chung-Pei Ma, arXiv:0909.3840 [ps, pdf, other]
Comments: 10 pages, 6 figures. Submitted to ApJ

UV Continuum Slope and Dust Obscuration from z~6 to z~2: The Star Formation Rate Density at High Redshift
R.J. Bouwens, G.D. Illingworth, M. Franx, R-R. Chary, G.R. Meurer, C.J. Conselice, H. Ford, M. Giavalisco, P. van Dokkum, arXiv:0909.4074 [ps, pdf, other]
Comments: 30 pages, 15 figures, 7 tables, accepted for publication in the Astrophysical Journal

HI kinematics and dynamics of Messier 31
Laurent Chemin, Claude Carignan, Tyler Foster, arXiv:0909.3846 [ps, pdf, other]

Comments: Accepted for publication in the Astrophysical Journal, 22 pages, 17 figures. For a higher resolution version of the article, see this http URL

Low Resolution Spectral Templates For AGNs and Galaxies From 0.03 -- 30 microns
R.J. Assef, C.S. Kochanek, M. Brodwin, R. Cool, W. Forman, A.H. Gonzalez, R.C. Hickox, C. Jones, E. Le Floc'h, J. Moustakas, S.S. Murray, D. Stern, arXiv:0909.3849 [ps, pdf, other]

Comments: Submitted to The Astrophysical Journal. 23 text pages + 3 tables + 18 figures. Fortran codes, templates and electronic tables available at this http URL

Cosmic ray driven outflows from high redshift galaxies
Saumyadip Samui, Kandaswamy Subramanian, Raghunathan Srianand, arXiv:0909.3854 [pdf, other]
Comments: 14 pages, 7 figures, Submitted to MNRAS

As with all CR-driven models this relies on assuming that supernovae losing the vast majority (~90%) of their initial kinetic energy in order for the energy associated with CRs to then be significant in the remaining total. This may apply to quiescently star forming galaxies, but its a bad assumption for actively star forming galaxies.

Black Holes and AGN

Title: Characterising the Far-infrared Properties of Distant X-ray Detected AGNs: Evidence for Evolution in the Infrared--X-ray Luminosity Ratio
J. R. Mullaney, D. M. Alexander, M. Huynh, A. D. Goulding, D. Frayer, arXiv:0909.3842 [ps, pdf, other]
Comments: 20 pages, 11 figures, MNRAS accepted

Theoretical Cosmology

Galaxies in a simulated ΛCDM universe - II. Observable properties and constraints on feedback
Kereš, Dušan; Katz, Neal; Davé, Romeel; Fardal, Mark; Weinberg, David H., 2009, MNRAS, 396, 2332
Full Text: HTML, PDF (1885k)

In short they find that the over-cooling problem remains, and existing (simplistic) feedback recipes do NOT fix it.

Galaxies in a simulated ΛCDM Universe - I. Cold mode and hot cores
Kereš, Dušan; Katz, Neal; Fardal, Mark; Davé, Romeel; Weinberg, David H., 2009, MNRAS, 395, 160
Full Text: HTML, PDF (44390k)

Updated version of the older stuff on the relative strengths of cold mode and hot mode accretion onto galaxies and how accretion rates onto galaxies relate to the simulated star formation rates. NB: The end up with 3 times too many baryons in galaxies, so should we still believe that accretion is being handled correctly?

The Modelling of Feedback Processes in Cosmological Simulations of Disk Galaxy Formation
Franziska Piontek, Matthias Steinmetz, arXiv:0909.4167 [ps, pdf, other]
Comments: 21 pages, 27 figures, submitted to MNRAS

Stars, Supernovae and Planets

Discovery of Strong Radiative Recombination Continua from The Supernova Remnant IC 443 with Suzaku
Hiroya Yamaguchi, Midori Ozawa, Katsuji Koyama, Kuniaki Masai, Junko S. Hiraga, Masanobu Ozaki, Daisuke Yonetoku, arXiv:0909.3848 [ps, pdf, other]
Comments: 5 pages, 5 figures, accepted by ApJ Letter

Cosmic Origins Spectrograph Observations of the Chemical Composition of LMC N132D
Kevin France, Matthew Beasley, Brian A. Keeney, Charles W. Danforth, Cynthia S. Froning, James C. Green, arXiv:0909.4110 [ps, pdf, other]
Comments: 5 pages, 4 figures. Submitted to ApJL

Prompt Ia Supernovae Are Significantly Delayed
Cody Raskin, Evan Scannapieco, James Rhoads, Massimo Della Valle, arXiv:0909.4293 [pdf, other]
Comments: 6 pages, 6 figures, ApJ, in press

From their abstract: "Our approach confines the analysis only to the relevant portions of the hosts, allowing us to show that even so-called "prompt" SNe Ia that trace star-formation on cosmic timescales exhibit a significant delay time of 200-500 million years."

Radiation-Hydrodynamic Models of X-Ray & EUV Photoevaporating Protoplanetary Discs
J. E. Owen, B. Ercolano, C. J. Clarke, R. D. Alexander, arXiv:0909.4309 [ps, pdf, other]
Comments: 16 pages, 14 figures, accepted for publication in MNRAS

X-rays are the dominant driving mechanism for photoevaporation.

The Planetary Nebula Luminosity Function: Pieces of the Puzzle
Robin Ciardullo, arXiv:0909.4356 [ps, pdf, other]
Comments: 7 pages, including 7 figures; presentation at the workshop on the Legacies of the Macquarie/AAO/Strasbourg H-alpha Planetary Nebula project, accepted for publication in PASA

Note to self: Must read, as may have implications for understanding compact H-alpha point sources in M82 ACS data.

3D models of radiatively driven colliding winds in massive O+O star binaries - III. Thermal X-ray emission
J. M. Pittard, E. R. Parkin, arXiv:0909.4383 [ps, pdf, other]
Comments: 29 pages, 23 figures, accepted for publication in MNRAS

Other

Astroinformatics: A 21st Century Approach to Astronomy
Kirk D. Borne, arXiv:0909.3892 [pdf, other]
Comments: 14 pages total: 1 cover page, 3 pages of co-signers, plus 10 pages, Astro2010 Decadal Survey State of the Profession Position Paper

Galaxies and Cladistics
Didier Fraix-Burnet, arXiv:0909.4164 [ps, pdf, other]
Comments: Talk given at the "12th Evolutionary Biology Meeting" held in Marseille, France, Sept. 24-26, 2008
Journal-ref: Evolutionary Biology. Concept, Modeling, and Application, Pontarotti, Pierre (Ed.) (2009) 363-378

MacArthur Fellows for 2009 announced

2009-09-23T08:45:00.003-04:00

This years crop of MacArthur Fellows (the so-called genius grants) has just been announced - the list of this year's Fellows is well worth a look. I like the diversity in occupation and age they cover - its not just thirty-somethings in fashionable areas.

Interesting Astrophysics: Sep 16 to Sep 18

2009-09-18T11:22:00.002-04:00

Both ram-pressure stripping and the neutral hydrogen content of galaxies stand out as topics this week. The issue of what are the elemental abundances in the Sun continues to elude solution.

Galaxies and Starbursts

Ram pressure stripping of disk galaxies in galaxy clusters
E. Roediger, arXiv:0909.2638 [pdf, other]

Comments: 11 pages, 4 figures, to appear in proceedings of symposium "Matter Cycles of Galaxies in Clusters" at JENAM 2008 (Vienna, Sept 2008), to be published in special issue of Astronomische Nachrichten in Nov 2009. Version with full resolution figures at this http URL

Infrared Luminosities and Dust Properties of z ~ 2 Dust-Obscured Galaxies
R. S. Bussmann, Arjun Dey, C. Borys, V. Desai, B. T. Jannuzi, E. Le Floc'h, J. Melbourne, K. Sheth, B. T. Soifer, arXiv:0909.2650 [ps, pdf, other]
Comments: 16 pages, 7 figures, 6 tables; accepted to the ApJ

Setting the normalcy level of HI properties in isolated galaxies
D. Espada, L. Verdes-Montenegro, E. Athanassoula, A. Bosma, W. K. Huchtmeier, S. Leon, U. Lisenfeld, J. Sabater, J. Sulentic, S. Verley, M. Yun, arXiv:0909.2736 [ps, pdf, other]
Comments: 4 pages, 2 figures, Conference 'Galaxies in Isolation: Exploring Nature vs. Nurture', Granada, 12-15 May 2009. To be published in the ASP Conference Series

Only the Lonely: HI Imaging of Void Galaxies
K. Stanonik, E. Platen, M. A. Aragon-Calvo, J. H. van Gorkom, R. van de Weygaert, J. M. van der Hulst, K. Kovac, C.-W. Yip, P. J. E. Peebles, arXiv:0909.2869 [ps, pdf, other]
Comments: 4 pages, to be published in the proceedings of the conference "Galaxies in Isolation" (12-15 May 2009; Granada, Spain)

Low-column density HVC and IVC gas in the halo of the Milky Way
N. Ben Bekhti, P. Richter, M. T. Murphy, arXiv:0909.2797 [ps, pdf, other]
Comments: 4 pages, 2 figures, in proceedings of "Panoramic Radio Astronomy: Wide-field 1-2 GHz research on galaxy evolution - PRA2009"

Does Stellar Feedback Create HI Holes? An HST/VLA Study of Holmberg II
Daniel R. Weisz, Evan D. Skillman, John M. Cannon, Andrew E. Dolphin, Robert C. Kennicutt Jr., Jance Lee, Fabian Walter, arXiv:0909.3025 [ps, pdf, other]

Comments: Accepted for Publication in The Astrophysical Journal; 28 Pages, 31 Figures, a version of this paper with full resolution figures is available at this http URL

The Tail of the Stripped Gas that Cooled: HI, Halpha and X-ray Observational Signatures of Ram Pressure Stripping
Stephanie Tonnesen, Greg L. Bryan, arXiv:0909.3097 [ps, pdf, other]

Comments: 18 pages, 11 figures, submitted to ApJ

Dust Emissivity Variations In the Milky Way
D. Paradis, J.-Ph. Bernard, C. Meny, arXiv:0909.3236 [ps, pdf, other]

Comments: 16 pages, 6 figures, accepted in A&A

Black Holes and AGN

A strong excess in the 20-100 keV emission of NGC 1365
G. Risaliti, V. Braito, V. Laparola, S. Bianchi, M. Elvis, G. Fabbiano, R. Maiolino, G. Matt, J. Reeves, M. Salvati, J. Wang, arXiv:0909.2820 [ps, pdf, other]
Comments: 13 pages, 3 figures. Accepted for publication in ApJ Letters

XMM-Newton Observations of a Complete Sample of Optically Selected Type 2 Seyfert Galaxies
Stephanie M. LaMassa, Timothy M. Heckman, Andrew A. Ptak, Ann Hornschemeier, Lucimara Martins, Paule Sonnentrucker, Christy Tremonti, arXiv:0909.3044 [ps, pdf, other]
Comments: accepted for publication to ApJ; 48 pages, 15 figures

Stars, Supernovae and Planets

New Solar Composition: The Problem With Solar Models Revisited
Aldo Serenelli, Sarbani Basu, Jason W. Ferguson, Martin Asplund, arXiv:0909.2668 [ps, pdf, other]
Comments: 11 pages, including 3 tables and 2 figures. Submitted to ApJL

From their abstract: "We find the improved input physics in the models has minor effects on the solar model structure and we confirm that the model using high (older) metallicity determinations gives consistent results with helioseismology."

Public Understanding of Science

Galaxy Zoo: Exploring the Motivations of Citizen Science Volunteers
M. Jordan Raddick, Georgia Bracey, Pamela L. Gay, Chris J. Lintott, Phil Murray, Kevin Schawinski, Alexander S. Szalay, Jan Vandenberg, arXiv:0909.2925 [pdf, other]
Comments: 15 pages, 3 figures

Planck first light

2009-09-17T13:12:00.002-04:00

The BBC discusses ESA's Planck mission's first light images.

Hubble post-servicing "first light" press release

2009-09-11T09:02:00.002-04:00

The full list of HST post-servicing "first-light" press release images and spectra (in image form, sigh) featuring WFC3 and COS can be found at the STScI website here.

Interesting Astrophysics: Sep 07 to Sep 11

2009-09-11T08:59:00.004-04:00

Of particular note there are interesting papers on theoretical models of dust-driven stellar winds (Mattsson et al) and SN Ia-driven galactic winds (Tang et al), along with observations of z~3 star forming galaxies showing signs of superwinds driven by core collapse supernova activity (Lemoine-Busserolle et al).

I also found Guio & Achilleos's paper on image decomposition using Voronoi tessellation quite interesting.

Galaxies and Starbursts

Cosmic-ray driven dynamo in the interstellar medium of irregular galaxies
H. Siejkowski, M. Soida, K. Otmianowska-Mazur, M. Hanasz, D.J. Bomans, arXiv:0909.0926 [ps, pdf, other]
Comments: 8 pages, 6 figures, submitted to A&A

The Distribution of Stars and Stellar Remnants at the Galactic Center
David Merritt, arXiv:0909.1318 [ps, pdf, other]
Comments: 22 pages, 18 figures

2D Kinematics and Physical Properties of z~3 Star-Forming Galaxies
M. Lemoine-Busserolle, A. Bunker, F. Lamareille, M. Kissler-Patig, arXiv:0909.1386 [pdf, other]
Comments: 14 pages and 16 figures

Their UV spectra show ISM lines blue shifted with respect to [O III]. Galactic winds! Although of course I shouldn't be surprised.

MMTF-Halpha and HST-FUV Imaging of the Filamentary Complex in Abell 1795
Michael McDonald, Sylvain Veilleux, arXiv:0909.1554 [ps, pdf, other]
Comments: Accepted for publication in ApJ Letters, 6 pages, 4 figures, 1 table

Investigating the far-IR/radio correlation of star-forming Galaxies to z= 3
N. Seymour, M. Huynh, T. Dwelly, M. Symeonidis, A. Hopkins, I. M. McHardy, M. J. Page, G. Rieke, 2009, MNRAS, 398, 1573
Full Text: HTML, PDF (Size: 751K)

Numerical Astrophysics & Hydrodynamics

Storm fronts over galaxy discs: models of how waves generate extraplanar gas and its anomalous kinematics
Curtis Struck and Daniel C. Smith, 2009, MNRAS, 398, 1069
Full Text: HTML, PDF (Size: 23343K)

The VOISE algorithm: a versatile tool for automatic segmentation of astronomical images
P. Guio and N. Achilleos, 2009, MNRAS, 398, 1254
Full Text: HTML, PDF (Size: 1354K)

Type Ia supernova-driven Galactic bulge wind
Shikui Tang, Q. Daniel Wang, Mordecai-Mark Mac Low, M. Ryan Joung, 2009, MNRAS, 398, 1468
Full Text: HTML, PDF (Size: 18550K)

The fragmentation of expanding shells – I. Limitations of the thin-shell approximation
James E. Dale, Richard Wünsch, Anthony Whitworth, Jan Palouš, 2009, MNRAS, 398, 1537
Full Text: HTML, PDF (Size: 16967K)

Stars, Supernovae and Planets

The relation between the most-massive star and its parental star cluster mass
C. Weidner, P. Kroupa, I. Bonnell, arXiv:0909.1555 [ps, pdf, other]
Comments: 26 pages, 13 figures, 3 tables, accepted for publication in MNRAS

Dust Driven Mass Loss from Carbon Stars as Function of Stellar Parameters - I. A Grid of Solar-metallicity Wind Models
Lars Mattsson, Rurik Wahlin, Susanne Hoefner, arXiv:0909.1513 [ps, pdf, other]
Comments: 27 pages, 11 figures, accepted for publication in Astronomy & Astrophysics

Off to Mars, but not the Moon?

2009-09-09T09:00:00.005-04:00

The summary of the Human Space Flight Review Committee report requested by the Obama administration advocates a long-term program with Mars as the long term goal (i.e. no set date), de-emphasising any return to the Moon:

... NASA has drafted a concept proposal called "Generation Mars" which envisions a 30-year blueprint for developing technologies, staging precursor missions to asteroids and other destinations, and building grassroots support for eventual human expeditions to Mars.

It also offers an unsurprising warning:

"The U.S. human spaceflight program appears to be on an unsustainable trajectory. It is perpetuating the perilous practice of pursuing goals that do not match allocated resources," the report summary said.

[Hat tip: TPM/Reuters]

Interesting Astrophysics: Sep 01 to Sep 04

2009-09-04T09:09:00.002-04:00

Of the 270 preprints that appeared on arXiv.org in the last week there were 16 that caught my eye.

Just on my favorite subject of galactic winds, Swinbank et al find evidence a galactic wind in a starburst galaxy at redshift z=4.9, Martin & Bouche present their Fe II and Mg II absorption line studies of wind in local ULIRGs, and Heesen et al present radio data on NGC 253's wind.

Galaxies and Starbursts

Probing the Excitation of Extreme Starbursts: High Resolution Mid-IR Spectroscopy of Blue Compact Dwarfs
Lei Hao, Yanling Wu, V. Charmandaris, H. W. W. Spoon, J. Bernard-Salas, D. Devost, V. Lebouteiller, J. R. Houck, arXiv:0908.4084 [ps, pdf, other]
Comments: 15 pages, including 1 table and 14 figures. Accepted by ApJ

A Maximum Stellar Surface Density in Dense Stellar Systems
Philip F. Hopkins, Norman Murray, Eliot Quataert, Todd A. Thompson, arXiv:0908.4088 [ps, pdf, other]
Comments: 6 pages, 2 figures, submitted to MNRAS Letters

A Spatially Resolved Map of the Kinematics, Star-Formation and Stellar Mass Assembly in a Star-Forming Galaxy at z=4.9
Mark Swinbank, Tracy Webb, Johan Richard, Richard Bower, Richard Ellis, Garth Illingworth, Tucker Jones, Mariska Kriek, Ian Smail, Dan Stark, Pieter Van Dokkum, rXiv:0909.0111 [ps, pdf, other]
Comments: Accepted for publication in MNRAS. 11 pages, 7 figures

Is this the highest redshift starbursting galaxy with an identified outflow?

Quantitative determination of the AGN content in local ULIRGs through L-band spectroscopy
G. Risaliti, M. Imanishi, E. Sani, arXiv:0908.4544 [ps, pdf, other]
Comments: 8 Pages, 5 figures. Accepted for publication in MNRAS

Physical Conditions in the Low-Ionization Component of Starburst Outflows: The Shape of Near-Ultraviolet and Optical Absorption-Line Troughs in Keck Spectra of ULIRGs
Crystal L. Martin, Nicolas Bouche, arXiv:0908.4271 [ps, pdf, other]
Comments: 28 pages, 10 figures, to appear in ApJ

Very interesting and impressive work. The variation of the cloud covering fraction with velocity should prove a particularly powerful model discriminant.

The starburst-GRB connection
Jens Dreyer, Julia K. Becker, Wolfgang Rhode, arXiv:0909.0158 [ps, pdf, other]
Comments: 4 pages, 4 figures, contribution to the 31st ICRC, Lodz, Poland, 2009

Transport of cosmic rays in the nearby starburst galaxy NGC 253
Volker Heesen, Rainer Beck, Marita Krause, Ralf-Jürgen Dettmar, arXiv:0909.0282 [ps, pdf, other]
Comments: 6 pages, 9 figures, to be published in Astronomische Nachrichten (proceedings of Symposium 6 of the JENAM 2008, Vienna)

Tracing Star Formation in Cool Core Clusters with GALEX
Amalia Hicks, Richard F. Mushotzky, Megan Donahue, arXiv:0909.0257 [pdf, other]
Comments:
4 pages, 4 figures; to appear in proceedings of The Monster's Fiery
Breath: Feedback in Galaxies, Groups, and Clusters (AIP conference
series)

Local Luminous Infrared Galaxies: Spatially resolved mid-infrared observations with Spitzer/IRS
Almudena Alonso-Herrero, Miguel Pereira-Santaella, George H. Rieke, Luis Colina, Charles W. Engelbracht, Pablo Perez-Gonzalez, Tanio Diaz-Santos, J. D. T. Smith, arXiv:0909.0658 [ps, pdf, other]
Comments: Accepted for publication in Advances in Space Research

Numerical and Theoretical Astrophysics

Computational Eulerian Hydrodynamics and Galilean Invariance
Brant E. Robertson, Andrey V. Kravtsov, Nickolay Y. Gnedin, Tom Abel, Douglas H. Rudd, arXiv:0909.0513 [ps, pdf, other]

Comments: Submitted to MNRAS. Figures degraded. For high-resolution color figures and movies of the numerical simulations, please visit this http URL

From their abstract: "In this work, we critically examine recent claims [i.e. Springel 2009] that these methods violate Galilean invariance of the Euler equations. We demonstrate that Eulerian hydrodynamics methods do converge to a Galilean-invariant solution, provided a well-defined convergent solution exists. Specifically, we show that numerical diffusion, resulting from diffusion-like terms in the discretized hydrodynamical equations solved by Eulerian methods, accounts for the effects previously identified as evidence for the Galilean non-invariance of these methods."

Oct-tree Method on GPU
N.Nakasato, arXiv:0909.0541 [ps, pdf, other]
Comments: Poster paper to be appeared in SC09

Turbulence and Mixing in the Intracluster Medium
P. Sharma, B. D. G. Chandran, E. Quataert, I. J. Parrish, arXiv:0909.0270 [ps, pdf, other]
Comments: 8 pages, 2 figs., submitted to the conference proceedings of "The Monster's Fiery Breath;" a follow up of arXiv:0901.4786 focusing on the general mixing properties of the ICM

High Energy Astrophysics

Radial Distribution of X-ray Point Sources near the Galactic Center
Jaesub Hong, Maureen van den Berg, Jonathan E. Grindlay, Silas Laycock, arXiv:0908.4306 [ps, pdf, other]
Comments: 17 pages, 7 figures, 6 tables, accepted for publication in Astrophysical Journal

Stars. Supernovae and Planets

Atlas of Vega: 3850 -- 6860 Angstroms
Hyun-Sook Kim, Inwoo Han, G. Valyavin, Byeong-Cheol Lee, V. Shimansky, G.A. Galazutdinov, arXiv:0908.4081 [ps, pdf, other]
Comments: 9 pages, 1 table, 4 figures, accepted to be published in The Publications of the Astronomical Society of the Pacific (PASP)

Balmer-Dominated Shocks: A Concise Review
Kevin Heng, arXiv:0908.4080 [ps, pdf, other]
Comments: 20 pages, 7 figures (double-columned, font size 10). Submitted to PASA. Comments welcome

Other

A Color All-Sky Panorama Image of the Milky Way
Axel Mellinger, arXiv:0908.4360 [pdf, other]
Comments: 7 figures, submitted to PASP

Quality of each US state's science standards evaluated. MD gets a C

2009-09-02T08:48:00.004-04:00

Mead and Mates evaluate state science standards with respect to their treatment of evolution and cosmology:

Our survey indicates that science standards tend to cover evolution more extensively than they did a decade ago, and that the average quality of the treatment has increased. However, certain types of creationist language are also becoming more common in state standards. We also discuss the history and role of state science standards in American public education.

I'd assumed that the Mid-Atlantic and New England states would all do well, but Maryland only gets a C, along with New York and Maine, while Connecticut gets a D. PA surprisingly enough gets an A.

MD gets a C thanks to "No human evolution. Discussion of cosmology in earth and space standards lacking." Connecticut is even worse: "Human evolution has been dropped. Despite specific reference to evolution in PreK-8 framework, there is no mention of age of the earth, fossils, Big Bang theory, plate tectonics, etc. "

[Image taken from their paper.]

Mead, L.S. & Mates, A., 2009, Evolution: Education and Outreach, 2(3): 359-371.