Friday, March 27, 2009

Interesting Astrophysics: Mar 23 to Mar 27

It has been a relatively quite week in terms of astrophysical papers and preprints I consider interesting, although I must admit to some distraction caused by the major ongoing software upgrade (and possible hardware) problems that I am experiencing with my primary workstation.

I've also included our M82 supernova feedback efficiency paper in the list. I was going to write a short separate post describing it, but I'm too busy with trying to fix my workstation to consider that at the moment.

Galaxies and Starbursts

Collisional debris as laboratories to study star formation
M. Boquien, P.-A. Duc, Y. Wu, V. Charmandaris, U. Lisenfeld, J. Braine, E. Brinks, J. Iglesias-Páramo, C. K. Xu, arXiv:0903.3403 [pdf, other]
Comments: 18 pages, 19 figures, accepted for publication in The astronomical journal

The effect of ram pressure on the star formation, mass distribution and morphology of galaxies
W. Kapferer, C. Sluka, S. Schindler, C. Ferrari, B. Ziegler, arXiv:0903.3818 [ps, pdf, other]
Comments: 19 pages, 25 figures, A&A accepted, high resolution version can be
found at this http URL

A Population of Metal-Poor Galaxies with ~L* Luminosities at Intermediate Redshifts
John J. Salzer, Anna L. Williams, Caryl Gronwall, arXiv:0903.3948 [ps, pdf, other]
Comments: 6 pages, 3 figures; to appear in 10 April 2009 ApJL

Mid-Infrared Spectroscopy of Submillimeter Galaxies: Extended Star Formation in Massive High Redshift Galaxies
Karín Menéndez-Delmestre, Andrew W. Blain, Ian Smail, Dave M. Alexander, Scott C. Chapman, Lee Armus, Dave Frayer, Rob J. Ivison, Harry Teplitz, arXiv:0903.4017 [ps, pdf, other]
Comments: 21 pages, 11 figures, accepted to The Astrophysical Journal

Strong z~0.5 O VI Absorption Toward PKS 0405-123: Implications for Ionization and Metallicity of the Cosmic Web
J.Christopher Howk, Joseph S. Ribaudo, Nicolas Lehner, J. Xavier Prochaska, Hsiao-Wen Chen, arXiv:0903.3963 [ps, pdf, other]
Comments: Accepted for publication in MNRAS. 21 pages. Abstract abridged slightly

A Simple Model for the Relationship Between Star Formation and Surface Density
C. L. Dobbs, J. E. Pringle, arXiv:0903.4098 [pdf, other]
Comments: 11 pages, 11 figures, accepted by MNRAS

The evolution of the mass-metallicity relation in SDSS galaxies uncovered by astropaleontology
N. Vale Asari, G. Stasinska, R. Cid Fernandes, J. M. Gomes, M. Schlickmann, A. Mateus, W. Schoenell, arXiv:0903.4167 [ps, pdf, other]
Comments: Accepted for publication in MNRAS

Their result (M-Z for galaxies with log M > 10) is not necessarily inconsistent with the conclusion of Tremonti et al (2004) that outflows shape the galaxy M-yeff relatio below a characteristic mass of log M ~ 10, above which galaxies act as closed boxes.

Supernova feedback efficiency and mass loading in the starburst and galactic superwind exemplar M82
David K. Strickland, Timothy M. Heckman, arXiv:0903.4175 [ps, pdf, other]
Comments: Accepted for publication in the Astrophysical Journal. 29 pages, 12 figures

Black Holes and AGN

Evidence for X-ray synchrotron emission from simultaneous mid-IR to X-ray observations of a strong Sgr A* flare
K. Dodds-Eden, et al, arXiv:0903.3416 [ps, pdf, other]
Comments: Accepted for publication in ApJ, 49 pages, 9 figures

Eddington ratio and accretion efficiency in AGN evolution
S.I. Raimundo, A. C. Fabian, arXiv:0903.3432 [ps, pdf, other]
Comments: Accepted for publication in MNRAS, 5 pages

Stars, Supernovae and Planets

The Disappearance of the Progenitors of Supernovae 1993J and 2003gd
Justyn R. Maund, Stephen J. Smartt, arXiv:0903.3772 [ps, pdf, other]
Comments: Science, in press, published online 19/03/09, 28 pages (MS+SOM) (high-res figures available at this http URL)

Both progenitors were Red Supergiants.


Astronomical Software Wants To Be Free: A Manifesto
Benjamin J. Weiner, et al, arXiv:0903.3971 [ps, pdf, other]
Comments: State of the Profession white paper submitted to the Astro2010 Decadal Survey. The authors welcome comments and discussion

Argues that astronomical software development should be taken seriously as an academic endeavor (i.e in terms of career development), and should also be funded adequately. But it ignores the issue of certain projects (SDSS's spectroscopic pipeline, FUSE, etc) relying on user's having access to non-free non-cheap commercial software packages like IDL. All in all its an interesting issue that is worth the Decadal Survey's time taking into account, but its still small fry compared to the trifecta of problems associated with career development demographics, funding and overly-large missions.

Tuesday, March 24, 2009


Our big M82 supernova feedback efficiency and mass loading theory paper was accepted by the ApJ today!

The preprint should appear on arXiv on Thursday.

The deliberately garish image to the right is Figure 1 in the paper. Its the central 5 kpc x 5 kpc of M82 as seen in soft X-ray emission (red, showing hot gas at ~5 million degrees K in the extended superwind), optical R-band (green, showing starlight from the disk of the galaxy), and diffuse hard X-ray emission (blue, a combination of emission from very hot gas at 30-80 million degrees K and possibly non-thermal continuum emission). The white circle outlines a radius of 500 pc from the center of M82, highlighting the close association of the hard X-ray emission with the central starburst region.

Friday, March 20, 2009

Interesting Astrophysics: Mar 16 to Mar 20

An unusually large crop of interesting star/supernova/star cluster related preprints attracted my attention this week. From the largest (radius) star in the LMC through photon-tiring in radiation driven winds, super-hard X-ray emission from Eta Carinae, to an anomaly with the classic wind-blown bubble, the "Bubble Nebula."

Galaxies and Starbursts

The Relationship Between Intergalactic HI/OVI and Nearby (z<0.017) Galaxies
B.P. Wakker, B.D. Savage, arXiv:0903.2259 [ps, pdf, other]
Comments: ApJ Supplement, in press

On the massive star content of the nearby dwarf irregular Wolf-Rayet galaxy IC 4662
P.A. Crowther, J.L. Bibby, arXiv:0903.2288 [ps, pdf, other]
Comments: 10 pages, 4 figures, accepted for Astronomy & Astrophysics

The Vela Cloud: A Giant HI Anomaly in the NGC 3256 Group
Jayanne English, Baerbel Koribalski, Joss Bland-Hawthorn, Ken Freeman, Claudia McCain, arXiv:0903.2690 [ps, pdf, other]
Comments: 46 pages, 11 figures, submitted to AJ

The chemical evolution of galaxies within the IGIMF theory: the [alpha/Fe] ratios and downsizing
Simone Recchi, Francesco Calura, Pavel Kroupa, arXiv:0903.2395 [ps, pdf, other]
Comments: 13 pages, 18 figures, accepted for publication in Astronomy and Astrophysics

The Star Formation Law at Low Surface Density
Ted K. Wyder, et al, arXiv:0903.3015 [ps, pdf, other]
Comments: 53 pages, 21 Figures, accepted for publication in the ApJ

Black Holes and AGN

X-ray Properties of Intermediate-Mass Black Holes in Active Galaxies. II. X-ray-Bright Accretion and Possible Evidence for Slim Disks
Louis-Benoit Desroches, Jenny E. Greene, Luis C. Ho, arXiv:0903.2257 [ps, pdf, other]
Comments: 11 pages, 6 figures, submitted to ApJ, emulateapj

The Suzaku View of the Swift/BAT AGNs (II): Time Variability and Spectra of Five "Hidden" AGNs
Lisa Winter, Richard Mushotzky, Yuichi Terashima, Yoshihiro Ueda, arXiv:0903.2802 [ps, pdf, other]
Comments: 45 pages, 16 figures, 10 tables, accepted to ApJ

Journey to the $M_{\rm BH} - \sigma$ relation: the fate of low mass black holes in the Universe
Marta Volonteri, Priyamvada Natarajan, arXiv:0903.2262 [pdf, other]
Comments: 8 pages, 5 figures, submitted to MNRAS

Numerical Astrophysics and Hydrodynamics

Simulating Magnetohydrodynamical Flow with Constrained Transport and Adaptive Mesh Refinement; Algorithms & Tests of the AstroBEAR Code
Andrew J. Cunningham, Adam Frank, Peggy Varniere, Sorin Mitran, Thomas W. Jones, arXiv:0710.0424 (replaced) [ps, pdf, other]
Comments: Additional Tests shown. Accepted to ApJS

Includes some images showing the interaction between a cylindrical cloud moving though an ambient medium with a magnetic field oriented in various directions w.r.t the cloud motion. B fields at 45 or 90 degree to the cloud motion/axis lead to less cloud disruption than if the B field is parallel to the cloud axis/motion.

Stars, Supernovae and Planets

The Physical Properties of the Red Supergiant WOH G64: The Largest Star Known?
Emily M. Levesque, Philip Massey, Bertrand Plez, Knut A. G. Olsen, arXiv:0903.2260 [ps, pdf, other]
Comments: 25 pages, 5 figures; accepted for publication in The Astronomical Journal

Super-hard X-Ray Emission from eta Carinae Observed with Suzaku
Akiko Sekiguchi, Masahiro Tsujimoto, Shunji Kitamoto, Manabu Ishida, Kenji Hamaguchi, Hideyuki Mori, Yohko Tsuboi, arXiv:0903.3307 [ps, pdf, other]
Comments: Accepted for publication in PASJ (10 pages, 7 Postscript figures)

Interestingly they argue that the 15-50 keV emission is either Inverse Compton emission arising between stellar UV photons and non-thermal electrons "or to the thermal bremsstrahlung of very hot plasma, and not to the bremsstrahlung by non-thermal electrons colliding with cold ambient matter."

On the behaviour of stellar winds that exceed the photon-tiring limit
Allard Jan van Marle, Stanley P. Owocki, Nir J. Shaviv, MNRAS, 2009, 394, 595
Full Text: HTML, PDF (Size: 9132K)

A steady-state continuum radiation-driven wind not have a mechanical luminosity exceeding the radiative luminosity at its base (the photon tiring limit). This paper explores non-steady state winds beyond the photon tiring limit. Interesting also w.r.t radiation-driven winds from AGN perhaps?

Unsolved Problems about Supernovae
Nino Panagia, arXiv:0903.3378 [ps, pdf, other]
Comments: 7 pages, Proceedings of 'Probing Stellar Populations out to the Distant Universe', Cefalu, Italy, Sep 7-19, 2008, AIP Conf. Proc. Series

Three-dimensional numerical model of the Omega Nebula (M17): simulated thermal X-ray emission
J. Reyes-Iturbide, P. F. Velázquez, M. Rosado, A. Rodríguez-González, R. F. González, A. Esquivel, 2009, MNRAS, 394, 1009
Full Text: HTML, PDF (Size: 4758K)

Study of Bubble Nebula using IUE high resolution Spectra
M. Y. Anand, B. A. I Kagali, Jayant Murthy, arXiv:0903.2828 [ps, pdf, other]
Comments: 9 pages, 6 figures, accepted in BASI

Interesting. Yet another expansion velocity - bubble size - stellar age anomaly, and this time in a spherical bubble around a main sequence star that really should follow the Weaver bubble model. The dynamical age of a wind blown bubble tbub = 0.6*Rbub/vbub, in this case ~3e4 years, which is much smaller than the age of the main sequence O star thought to have blown the bubble (~2e6 years). Yet the expansion velocity of vbub ~ 36 km/s is high enough that there is no reason to suspect the bubble has stalled, and its near perfect shape does not suggest irregular expansion.

Friday, March 13, 2009

Interesting Astrophysics: Mar 09 to Mar 13

A relatively quiet week in terms of interesting papers and preprints. Of particular note this week are Alonso-Herrero et al's Spitzer observations of NGC 3690, Iwasawa et al's study of Fe XXV emission in LIRGs, and Añorve-Zeferino et al's cluster wind + superbubble paper.

Galaxies and Starbursts

The Extreme Star Formation Activity of Arp299 Revealed by Spitzer IRS Spectral Mapping
Almudena Alonso-Herrero, George H. Rieke, Luis Colina, Miguel Pereira-Santaella, Macarena Garcia-Marin, J. D. T. Smith, Bernhard Brandl, Vassilis Charmandaris, Lee Armus, arXiv:0903.1495 [ps, pdf, other]
Comments: Accepted in ApJ

Arp299 is NGC 3690 + IC694.

High-ionization Fe K emission from luminous infrared galaxies
K. Iwasawa, D. B. Sanders, A. S. Evans, J. M. Massarella, L. Armus, J. A. Surace, arXiv:0903.1503 [ps, pdf, other]
Comments: 4 pages, 2 figures, ApJ Letters in press

Multiwavelength View of the Inner Spiral of NGC 1365
I. V. Strateva, S. Komossa, arXiv:0903.1548 [ps, pdf, other]
Comments: 15 pages, submitted to MNRAS

The SINS survey: SINFONI Integral Field Spectroscopy of z ~ 2 Star-forming Galaxies
N.M. Forster Schreiber, R. Genzel, N. Bouche, G. Cresci, R. Davies, P. Buschkamp, K. Shapiro, L. J. Tacconi, E. K. S. Hicks, S. Genel, A. E. Shapley, D. K. Erb, C. C. Steidel, D. Lutz, F. Eisenhauer, S. Gillessen, A. Sternberg, A. Renzini, A. Cimatti, E. Daddi, J. Kurk, S. Lilly, X. Kong, M. D. Lehnert, N. Nesvadba, A. Verma, H. McCracken, N. Arimoto, M. Mignoli, M. Onodera, arXiv:0903.1872 [ps, pdf, other]
Comments: 66 pages, 34 figures, submitted to Astrophysical Journal

The Star Formation and Nuclear Accretion Histories of Normal Galaxies in the AGES Survey
Casey R. Watson, Christopher S. Kochanek, William R. Forman, Ryan C. Hickox, Christine J. Jones, Michael J. I. Brown, Kate Brand, Arjun Dey, Buell T. Jannuzi, Almus T. Kenter, Steve S. Murray, Alexey Vikhlinin, Daniel J. Eisenstein, Giovani G. Fazio, Paul J. Green, Brian R. McNamara, Marcia Rieke, Joseph C. Shields, arXiv:0903.2219 [ps, pdf, other]
Comments: 19 pages, 15 figures, 3 tables, accepted for publication in ApJ

Effects of dust abundance on the far-infrared colours of blue compact dwarf galaxies
Hiroyuki Hirashita, Tomohiro T. Ichikawa, arXiv:0903.1946 [ps, pdf, other]
Comments: 12 pages, 8 figures, accepted for publication in MNRAS

Black Holes and AGN

The bulk kinetic power of radio jets in active galactic nuclei
Minfeng Gu, Xinwu Cao, D.R. Jiang, arXiv:0903.1896 [ps, pdf, other]
Comments: MNRAS accepted

The starburst-AGN connection: the role of young stellar populations in fueling supermassive black holes
Y.-M. Chen, J.-M. Wang, C.-S. Yan, C. Hu, S. Zhang, arXiv:0903.1901 [ps, pdf, other]
Comments: 4 pages, 2 color figures. ApJ Letters (in press)


Fresnel zone plates for Achromatic Imaging Survey of X-ray sources
S. Palit, S. K. Chakrabarti, D. Debnath, V. Yadav, A. Nandi, arXiv:0903.1540 [ps, pdf, other]
Comments: 4 Pages, 5 Figures, Proceeding of the 2nd Kolkata Conference on "Observational Evidence for the Black Holes in the Universe", Published in AIP, 2008
Journal-ref: 2008AIPC.1053..391P

Interstellar Medium

Interstellar Dust Models and Evolutionary Implications
B. T. Draine, arXiv:0903.1658 [ps, pdf, other]
Comments: 20 pages, to appear in "Cosmic Dust -- Near and Far", ed. Th. Henning, E. Grun, J. Steinacker (ASP Conf. Series)

On the X-ray emission from massive star clusters and their evolving superbubbles II. Detailed analytics and observational effects
G. A. Añorve-Zeferino, G. Tenorio-Tagle, S. Silich, arXiv:0903.1678 [ps, pdf, other]
Comments: 30 pages, 15 figures. Accepted by MNRAS

The Relation Between Optical Extinction and Hydrogen Column Density in the Galaxy
Tolga Guver, Feryal Ozel, arXiv:0903.2057 [ps, pdf, other]
Comments: submitted to MNRAS

They find $N_{\rm H} = (2.30 \pm 0.04) \times 10^{21} \times A_{\rm V}$.

Stars, Supernovae and Planets

SN 2008S: an electron capture SN from a super-AGB progenitor?
M.T. Botticella, et al, arXiv:0903.1286 [ps, pdf, other]
Comments: submitted to MNRAS

The Runaway White Dwarf LP400-22 Has a Companion
Mukremin Kilic, Warren R. Brown, Carlos Allende Prieto, B. Swift, S. J. Kenyon, J. Liebert, M. A. Agueros, arXiv:0903.1843 [ps, pdf, other]
Comments: ApJ Letters, in press

Thursday, March 12, 2009

What fuels star formation in galaxies? (part 2)

How do Galaxies fuel Star Formation? Where do they get the gas that forms new stars?

Back when I started this blog in 2006 I had a short post discussing the issue of where galaxies got the gas they use to fuel ongoing star formation from, which was meant to lead onto the discussion of a paper by Keres et al. (I never got around to discussing that paper.)

Star formation requires interstellar gas (specifically cold dense molecular gas), ... (a) where does the gas come from, and (b) what controls the star formation rate in a galaxy with a given amount of gas?
The old view (say in the 1980's era) was that galaxies accumulated the baryonic matter (in the form of neutral gas or an ionized plasma) into the center of the gravitational potential well (dominated by Dark Matter) they were forming within via dissipative processes (collision and radiation), and this essentially comprised their total gas budget for the rest of the life of the galaxy. Rapid collapse of the gas to the center of the potential well (within a dynamical time) created elliptical galaxies, whereas slower (less dissipative) accretion preserved angular momentum and led to the formation of rotation-support disk galaxies (i.e. spiral galaxies). Star formation rates in galaxies decreased with time exponentially (e.g. if you convert a fixed fraction eSF of your total gas budget to stars in every galactic rotation you get an exponential decrease in gas mass with a e-folding time constant 1/eSF).

So galaxies are just running down in this view, sooner or later running out of gas and becoming "red and dead", i.e. like ellipticals which presumably ran out of gas first.

The more modern viewpoint is to account for continued accretion of fresh intergalactic gas into the gravitational potential wells of galaxies. Differences between red (dead) and blue (actively star forming) galaxies may be in the character of the ongoing accretion process. If that accretion process changes your galaxy can change its type.

Gas falling into the potential well of massive galaxies gains enough gravitational potential energy to reach a velocity where the shock wave it encounters when hitting other gas heats it to X-ray emitting temperatures. At such temperatures the cooling time is long, so it has trouble losing enough energy to fall to the center of the potential well and end up in the galaxy. Instead it forms a hot but tenuous halo of gas surrounding the galaxy. So with decreased dissipation the gas has trouble fueling any star formation in the massive galaxy. Conversely the gas falling into the potential well of a lower mass galaxy is either never shocked, or if shock heated it only achieves temperatures where cooling is rapid (T < 106 K). So it dissipates its energy easily and falls into the galaxy at the center of the gravitational potential well, and is available to fuel additional star formation in this lower mass galaxy. Massive galaxies are predominantly ellipticals or low SF rate spirals, while actively star forming galaxies are typically lower mass galaxies, so the distinction between the different models of star formation in spiral versus elliptical galaxies is preserved but explained in a different manner (nature, rather than initial nurture, as it were).

Indeed, some would argue that the current star formation rate of a galaxy must closely matches its current accretion rate. This raises the question of whether enough gas is falling onto our own Galaxy to account for our star formation rate of 1-3 Solar masses per year. Again this is very different from the old picture of SF in galaxies where you started off with a fixed mass of gas and just consumed it until you run out.

The preceding discussion is only a crude cartoon view of the subject, but serves to introduce the subject. I brought this subject up again because I noticed one of the Astro2010 Decadal Survey White Papers is on the subject of where galaxies get their gas and how do they turn that gas into stars.

If you are interested in seeing what the latest state-of-the-art in this subject is, and where people who actually work on this subject would like to see it go, then please read

How do Galaxies Accrete Gas and Form Stars? by M.E. Putman, et al, arXiv:0902.4717 [ps, pdf, other].

It is written for an audience of professional astrophysicists, but their is content that an educated and interested layperson can benefit from.

Saturday, March 07, 2009


A former top NASA official has been indicted on charges of steering $9.6 million in agency funds to a consulting client.

The indictment accuses Stadd of steering money from an earth science appropriation to Mississippi State University, which was paying him as a consultant. Stadd is also accused of lying to NASA ethics officials investigating the matter.

He faces up to 15 years in prison if convicted on all three charges.

NASA officials on Friday declined to comment on the indictment.

Stadd, who joined NASA as chief of staff in 2001 and left the agency in 2003, was President George W. Bush's NASA transition chief in 2000. Stadd "was centrally involved in the organization and management of NASA," said John Logsdon, a Smithsonian Institution space scholar.

From AP news via TPM.

Friday, March 06, 2009

Interesting Astrophysics: Mar 02 to Mar 06

Another week's worth of interesting preprints. Of particular note this week are a number of papers on numerical utilities for astrophysics, e.g. XIM and GALEV, and quite a few star-related papers, in particular Claus Leitherer's discussion of stellar wind mass loss rates.

Galaxies and Starbursts

Do blue compact galaxies have red halos?
E. Zackrisson, G. Micheva, N. Bergvall, G. Ostlin, arXiv:0902.4695 [ps, pdf, other]
Comments: 5 pages, 3 figures. To appear in the proceedings of "Star-forming Dwarf Galaxies: Ariadne's Thread in the Cosmic Labyrinth", Crete, 2008

The SINS Survey: Broad H-alpha Emission in High-Redshift Star-Forming Galaxies
Kristen L. Shapiro, Reinhard Genzel, Eliot Quataert, Natascha M. Förster Schreiber, Richard Davies, Linda Tacconi, Lee Armus, Nicolas Bouché, Peter Buschkamp, Andrea Cimatti, Giovanni Cresci, Emanuele Daddi, Frank Eisenhauer, Dawn K. Erb, Shy Genel, Erin K. S. Hicks, Simon J. Lilly, Dieter Lutz, Alvio Renzini, Alice Shapley, Charles C. Steidel, Amiel Sternberg, arXiv:0902.4704 [ps, pdf, other]
Comments: 11 pages, 6 figures; submitted to ApJ

Broad (FWHM > 1500 km/s) H-alpha emission in stacked spectra of z~2 galaxies, caused by AGN or starburst-driven winds? Such a velocities is at or beyond the highest velocities observed in the H-alpha emission line or Na I absorption line in z << 1 starburst-driven winds, so personally I would not rush to attribute their observational result to superwinds.

What Are S0 Galaxies?
Sidney van den Bergh, arXiv:0902.4718 [ps, pdf, other]
Comments: ApJ (Letters), in press; 1 postscript figure

On the Early Evolution of Young Starbursts
Daniel Rosa-Gonzalez, Henrique Schmitt, Elena Terlevich, Roberto Terlevich, arXiv:0903.0552 [ps, pdf, other]
Comments: Comments: 6 pages, 5 figures, Proceedings of "A Long Walk Through Astronomy: A Celebration of Luis Carrasco's 60th Birthday", Huatulco, Mexico, October 2008, ed. E. Recillas, L. Aguilar, A. Luna, and J.R. Valdes; RevMexAA (Serie de Conferencias)

Did the Milky Way dwarf satellites enter the halo as a group?
Manuel Metz, Pavel Kroupa, Christian Theis, Gerhard Hensler, Helmut Jerjen, arXiv:0903.0375 [ps, pdf, other]
Comments: acc ApJ

The spiral structure of our Milky Way Galaxy
L. G. Hou, J. L. Han, W. B. Shi, arXiv:0903.0721 [ps, pdf, other]
Comments: 34 Pages, 10 Figures, 5 Tables. Accepted for publication in A&A

They argue that 2, 3 and 4 spiral arm models for the Milky Way all have problems. Maybe I'm reading it incorrectly, but their best model has five arms.

Elemental Abundances in the X-Ray Gas of Early-Type Galaxies with XMM and Chandra Observations
Jun Ji, Jimmy A. Irwin, Alex Athey, Joel N. Bregman, Edward J. Lloyd-Davies, arXiv:0903.0429 [ps, pdf, other]
Comments: 35 pages, 10 figures, accepted for publication in Astrophysical Journal

Hot gas halos around disk galaxies: Confronting cosmological simulations with observations
Jesper Rasmussen, Jesper Sommer-Larsen, Kristian Pedersen, Sune Toft, Andrew Benson, Richard G. Bower, Lisbeth F. Grove, arXiv:0903.0665 [ps, pdf, other]
Comments: 16 pages, 8 figures, ApJ accepted. Supersedes arXiv:astro-ph/0610893

Reanalysis of the NGC 5746 and NGC 5170 Chandra observations, along with new cosmological simulations. The older NGC 5746 observation was notable as the first claimed detection for a hot gaseous halo around a spiral galaxy that was not actively star forming. On reanalysis its a non-detection, the problem being the OBF contamination on Chandra ACIS.

Numerical Astrophysics and Hydrodynamics

Hydrodynamical simulations of Galactic fountains II: evolution of multiple fountains
Claudio Melioli, Fabrizio Brighenti, Annibale D'Ercole, E.M. de Gouveia Dal Pino, arXiv:0903.0720 [ps, pdf, other]
Comments: 19 pages, 18 figures, accepted for publication in MNRAS

XIM: A virtual X-ray observatory for hydrodynamic simulations
S. Heinz, M. Brüggen, arXiv:0903.0043 [ps, pdf, other]
Comments: Submitted to ApJ Supplements, 6 pages, 6 figures

GALEV evolutionary synthesis models - I. Code, input physics and web-interface
Ralf Kotulla, Uta Fritze, Peter Weilbacher, Peter Anders, arXiv:0903.0378 [ps, pdf, other]
Comments: accepted for publication in MNRAS; 26 pages, 25 figures; The GALEV web-page and the model interface can be found at this http URL; The appendix includes a pictorial introduction into evolutionary synthesis models.

What is Driving the HI Velocity Dispersion?
D. Tamburro, H.-W. Rix, A.K. Leroy, M.-M. Mac Low, F. Walter, R.C. Kennicutt, E. Brinks, W.J.G. de Blok, arXiv:0903.0183 [ps, pdf, other]

SN efficiency must be >= 0.1 within R_25 to account for HI line widths. Exterior to R_25 the main driver of turbulence must be the MRI, not SNe.

Hacking the Sky
R. J. Simpson, arXiv:0903.0484 [pdf]
Comments: 15 pages, conference" Astronomy: Networked Astronomy and the New Media", 2009, edited by R. J. Simpson, D. Ward-Thompson

Astronomical Instrumentation

Introduction to Millimeter/Sub-Millimeter Astronomy
T. L. Wilson, arXiv:0903.0562 [ps, pdf, other]
Comments: To be published in the Saas Fee Winter School 2008. 106 pages, 22 figures

Gamma-Ray Line Studies of Nuclei in the Cosmos
M. Leising, R. Diehl, arXiv:0903.0772 [pdf, other]
Comments: 17 pages, 5 figures, submitted to proceedings of Nuclei in the Cosmos X on 29 October 2008

Interstellar Medium

The Cycle of Dust in the Milky Way: Clues from the High-Redshift and Local Universe
Eli Dwek, Frederic Galliano, Anthony Jones, arXiv:0903.0006 [ps, pdf, other]
Comments: 16 pages, 9 figures. To be published in the Heidelberg 2008 Conference on "Cosmic Dust Near and Far"

Stars, Supernovae and Planets

Dust in Supernovae; Formation and Evolution
Takashi Kozasa, Takaya Nozawa, Nozomu Tominaga, Hideyuki Umeda, Keiichi Maeda, Ken'ichi Nomoto, arXiv:0903.0217 [ps, pdf, other]
Comments: To be published in the proceedings of "Cosmic Dust - Near and Far," eds Th. Henning, E. Grun, J. Steinacker, (Astronomical Society of the Pacific), held September 8 - 12, 2008, 21 pages, 12 figures

The lost siblings of the Sun
S. Portegies Zwart, arXiv:0903.0237 [ps, pdf, other]
Comments: Submitted to ApJ Letters

Altair - the 'hottest' magnetically active star in X-rays
J. Robrade, J.H.M.M. Schmitt, arXiv:0903.0966 [ps, pdf, other]
Comments: Accepted by A&A, 10 pages, 7 figures

Young Massive Clusters as probes of stellar evolution
Ben Davies, arXiv:0903.0979 [ps, pdf, other]
Comments: 8 pages, 3 figures. Review article to appear in the proceedings of "Hot and Cool: bridging the gaps in massive star evolution" - updated reference list

Empirical Mass-Loss Rates across the Upper Hertzsprung-Russell-Diagram
Claus Leitherer, arXiv:0903.0608 [pdf]
Comments: To appear in "Hot And Cool: Bridging Gaps in Massive Star Evolution", eds. C. Leitherer, Ph. D. Bennett, P. W. Morris & J. Th. van Loon (San Francisco: ASP)

Wednesday, March 04, 2009

International X-ray Observatory (IXO) white papers for Astro2010

Following on from this morning's post on Astro2010 Decadal Survey science white papers I should mention that the aim of my white paper (and various other white papers) is ultimately to emphasize the need for the US to engage in building and launching the International X-ray Observatory (IXO).

In terms of the science I am interested in, only IXO will have the capability to perform spectral-imaging of diffuse plasmas with high enough spectral resolution and high enough sensitivity to tell us what the rate of ejection from galaxies of gas, energy and newly-synthesized elements into the intergalactic medium is.

This entails being able to measure the velocity of the hot X-ray-emitting plasmas that drive superwinds in a sample of starburst galaxies covering a broad range in galaxy mass, which is impossible with the current generation of observatories, or even future non-X-ray observatories like HST/COS or NGST.

IXO, even if fully funded by all the international groups involved (NASA, ESA and JAXA), would have a launch date of around 2020. JAXA's ASTRO-H will have been launched well before then, around 2013 if all goes to plan, and it should be able to measure wind velocities in one or two of the brightest starburst-driven winds. These will be historic measurements, but won't be enough to establish how or if wind velocities vary with galaxy mass or star formation intensity. Ultimately we need to observe a decent sample, and IXO will be able to measure wind speeds more accurately in more objects.

Ultimately there are a broad range of pressing astrophysical questions that can only be answered with an observatory-class X-ray mission, which is what the broad range IXO white papers aim to demonstrate to the Decadal Survey panels. The full list of IXO-related Astro2010 science white papers (including mine) can be found here.

Astro2010 White Papers I think are interesting

The deadline for the submission of science White Paper to the U.S. National Academy of Science's Astro2010 Decadal Survey was Sunday 15th February 2009. Now its down to the poor saps on the actual survey panels to read (or skim) through vast numbers of seven page documents.

Although their aim is to convince the Decadal Survey panel members of the importance of their relative scientific areas to the future of astronomy and astrophysics in the U.S., these White Papers are interesting as mini-reviews of how their authors view their respective fields and how they'd like to see them develop.

Here are the White Papers that (a) were also posted on arXiv by their authors by March 3rd 2009, and that (b) I consider somewhat interesting, or (c) I had some involvement with and are therefore by definition interesting. This is a very small selection of the approximately 320 or so science White Papers submitted to the Decadal Survey.

I've trimmed the author lists down to "First Author, et al" (even in cases where there are only two authors) to avoid the artificial popularity contest created by the variable number of endorsers on each White Paper.

I've ordered them crudely in terms of our Galaxy, galaxies in general, high redshift, AGN, clusters, planets, stars and assorted other phenomena.

Structure and Dynamics of the Milky Way: an Astro2010 Science White Paper
Authors: M. J. Reid, K. M. Menten, A. Brunthaler, G. A. Moellenbrock, arXiv:0902.3928 [ps, pdf, other]
Comments: 8 pages, 2 figures

Young stellar clusters and star formation throughout the Galaxy
Authors: Eric Feigelson, arXiv:0903.0374 [pdf]

Comments: Science Working Paper for the Astro2010 Decadal Survey. For a version with color figures, see this http URL

The History of Star Formation in Galaxies
Authors: Thomas M. Brown, et al, arXiv:0902.2973 [pdf]
Comments: Science white paper submitted to the Astro2010 Decadal Survey. 7 pages, 4 figures, PDF

How do Galaxies Accrete Gas and Form Stars?
Authors: M.E. Putman, et al, arXiv:0902.4717 [ps, pdf, other]
Comments: 8 pages, Science white paper for the Astro2010 Decadal Survey, 2 color figures

The Star Formation Histories of Disk and E/S0 Galaxies from Resolved Stars
Authors: Knut A.G. Olsen, et al, arXiv:0902.4216 [pdf]
Comments: Science white paper submitted to Astro2010 Decadal Survey GAN Panel 7 pages + cover page, 2 figures

Kinematics and Formation Mechanisms of High-Redshift Galaxies
Authors: David R. Law, et al, arXiv:0902.2567 [pdf]
Comments: 8 pages total. White paper submitted to the Astro 2010 Decadal Survey

Nearby Galaxies: Templates for Galaxies Across Cosmic Time
Authors: F. J. Lockman, et al, arXiv:0902.3963 [pdf, other]
Comments: science white paper submitted to the US Astro2010 Decadal Survey

The Galactic Center: A Laboratory for Fundamental Astrophysics and Galactic Nuclei
Authors: A. Ghez, et al, arXiv:0903.0383 [ps, pdf, other]
Comments: An ASTRO2010 White Paper. Animations and high resolution images can be found at this http URL

The Very Local Universe in X-rays
Authors: A. Ptak, et al, arXiv:0902.4239 [pdf]
Comments: 8 pages, Astro2010 Science White paper. Full-resolution version available at this http URL

Starburst Galaxies: Outflows of Metals and Energy into the IGM
Authors: David K. Strickland, et al, arXiv:0902.2945 [pdf, other]
Comments: White Paper for US Astro2010 Decadal Survey. 7 pages. Technical supplement at this http URL

Astrophysics from the Highly-Redshifted 21 cm Line
Authors: Steven Furlanetto, et al, arXiv:0902.3011 [ps, pdf, other]
Comments: 8 pages, 5 figures, science white paper submitted to the US Astro2010 Decadal Survey "Galaxies across Cosmic Time" Science Frontier Panel

Radio Supernovae: Circum-Stellar Investigation (C.S.I.) of Supernova Progenitor Stars
Authors: Christopher J. Stockdale, et al, arXiv:0902.4059 [ps, pdf, other]
Comments: 8 pages, 4 figures. White Paper submitted to the Astro2010 SSE panel

Despite the slightly cheesy title (CSI? That is so five years ago.) this is actually a really interesting White Paper IMHO.

Plasma Physics Processes of the Interstellar Medium
Authors: Steven Spangler, et al, arXiv:0902.4181 [ps, pdf, other]
Comments: White paper submitted for consideration of the Astro2010 Decadal Survey Committee, in the area of "Galactic Neighborhood" (GAN)

In Situ Probes of the First Galaxies and Reionization: Gamma-ray Bursts
Authors: Matthew McQuinn, et al, arXiv:0902.3442 [ps, pdf, other]
Comments: 8 pages, 3 figures, science white paper submitted to the US Astro2010 Decadal Survey

Imaging the cool gas, dust, star formation, and AGN in the first galaxies
Authors: C.L. Carilli, et al, arXiv:0902.3671 [pdf, other]
Comments: 8 pages total. White paper submitted to the Astro 2010 Decadal Survey

High Redshift Radio Galaxies: Laboratories for Massive Galaxy and Cluster Formation in the early Universe
Authors: G. Miley, et al, arXiv:0902.3677 [ps, pdf, other]
Comments: 8 pages total. White paper submitted to the Astro 2010 Decadal Survey

The Growth of Supermassive Black Holes Across Cosmic Time
Authors: K. Nandra, et al, arXiv:0903.0547 [pdf]
Comments: 8 pages, Science White paper submitted to Astro2010 Decadal survey. Supplementary information available at this http URL

Diffuse baryonic matter beyond 2020
Authors: M. Markevitch, et al, arXiv:0902.3709 [pdf, other]
Comments: pdflatex, 9 pages, 3 color figures. White paper submitted for NRC Astro2010 Decadal Survey

Nice enough paper, but they totally cheated on the paper length. You're allowed 7 pages plus 1 cover page, including all figures and references. The Decadal Survey should not consider this paper. The rest of us managed to follow the rules. Every panel or time allocation committee I've been on seems to get at least one wise guy who thinks they can get away with an extra page, often in the hope that only the last page will be removed (often only with the reference list on it).

How and When do Planets Form? The Inner Regions of Planet Forming Disks at High Spatial and Spectral Resolution
Authors: R. Millan-Gabet, John D. Monnier, arXiv:0902.2576 [pdf]
Comments: Science White Paper submitted to the Astro2010 Decadal Survey

New Worlds: Evaluating terrestrial planets as astrophysical objects
Authors: Caleb A. Scharf, et al, arXiv:0902.2755 [pdf]
Comments: Submitted as a White Paper to the 2010 Astronomy & Astrophysics Decadal Survey

The Formation and Evolution of Planetary Systems: The Search for and Characterization of Young Planets
Authors: Charles Beichman, et al, arXiv:0902.2972 [pdf]
Comments: White Paper Submission to Astro2010

X-ray Studies of Planetary Systems: An Astro2010 Decadal Survey White Paper
Authors: Eric Feigelson, et al, arXiv:0903.0598 [pdf, other]

No Planet Left Behind: Investigating Planetary Diversity and Architecture with SIM Lite
Authors: S. R. Kulkarni, et al, arXiv:0902.3475 [ps, pdf, other]
Comments: 7 pages, 3 figures, submitted to The Astronomy and Astrophysics Decadal Survey

MARVELS: Revealing the Formation and Dynamical Evolution of Giant Planet Systems
Authors: Jian Ge, et al, arXiv:0903.0181 [ps, pdf, other]
Comments: Unpublished SDSS-III white paper for the US Decadal Survey. See this http URL for details of the international SDSS-III project

Toward the End of Stars: Discovering the Galaxy's Coldest Brown Dwarfs
Authors: Adam J. Burgasser, et al, arXiv:0902.2604 [pdf]
Comments: 8 pages, 3 figures, Astro2010 Science White Paper

Temporal Variability of Stars and Stellar Systems
Authors: T. A. Lister, et al, arXiv:0902.2966 [ps, pdf, other]
Comments: Submitted as a White Paper to the SSE Panel of the Astro2010 Decadal Survey

Quantifying Stellar Mass Loss with High Angular Resolution Imaging
Authors: Stephen Ridgway, et al, arXiv:0902.3008 [pdf]
Comments: Science white paper prepared for Astro2010

X-ray Timing of Neutron Stars, Astrophysical Probes of Extreme Physics
Authors: Z. Arzoumanian, et al, arXiv:0902.3264 [pdf]
Comments: 8 pages. Science white paper submitted to Astro2010: The Astronomy and Astrophysics Decadal Survey

X-ray Timing of Stellar Mass Black Holes
Authors: John A. Tomsick, et al, arXiv:0902.4238 [ps, pdf, other]
Comments: White paper submitted to the Astro 2010 Decadal Survey

Stellar-Mass Black Holes and Their Progenitors
Authors: J. M. Miller, et al, arXiv:0902.4677 [pdf]
Comments: Astro 2010 Science White Paper

Spin and Relativistic Phenomena Around Black Holes
Authors: L. Brenneman, et al, arXiv:0902.4691 [pdf]
Comments: Astro 2010 Science White Paper

Gravitational Wave Astronomy Using Pulsars: Massive Black Hole Mergers & the Early Universe
Authors: P. Demorest. et al, arXiv:0902.2968 [pdf, other]
Comments: 8 pages, white paper submitted to the Astro2010 Decadal Survey. For NANOGrav information, see this http URL

The Dynamic X-ray Sky of the Local Universe
Authors: Alicia M. Soderberg, et al, arXiv:0902.3674 [pdf]
Comments: 8 pages, 2 figures; White Paper submitted to the Astro2010 SSE panel

Origin and evolution of cosmic accelerators - the unique discovery potential of an UHE neutrino telescope
Authors: Pisin Chen, et al, arXiv:0902.3288 [pdf, other]
Comments: 7 pages, 3 figures, submitted to US Astronomy Decadal Survey (2010-2020)

Properties of Dark Matter Revealed by Astrometric Measurements of the Milky Way and Local Galaxies
Authors: Edward Shaya, et al, arXiv:0902.2835 [pdf]
Comments: 8 pages, 3 figures, White Paper for the Decadal Survey in Astrophysics

The Need for Plasma Astrophysics in Understanding Life Cycles of Active Galaxies
Authors: H. Li, et al, arXiv:0902.3469 [pdf]
Comments: a White Paper submitted to GCT and FCP panels of Astro2010

A New Era in Extragalactic Background Light Measurements: The Cosmic History of Accretion, Nucleosynthesis and Reionization
Authors: Asantha Cooray et al, arXiv:0902.2372 [ps, pdf, other]
Comments: 7 pages; Science White Paper for the US Astro 2010-2020 Decadal Survey. If interested in further community-wide efforts on this topic please contact the first author

Astrophysics with Radioactive Atomic Nuclei
Authors: R. Diehl et al, arXiv:0902.2494 [pdf]
Comments: 7 pages, white paper for US Nat.Acad.Sci. Decadal Survey "Astro2010"

Solid State Astrophysics: Probing Interstellar Dust and Gas Properties with X-rays
Authors: Julia C. Lee, et al, arXiv:0902.4671 [ps, pdf, other]
Comments: 8 pages, 6 figures. White paper submitted to the Astro2010 Decadal survey for Astronomy and Astrophysics

Understanding of the role of magnetic fields: Galactic perspective
Authors: A. Lazarian, S. Boldyrev, C. Forest, J. Sarff, P. Terry, arXiv:0902.3618 [pdf]
Comments: 8 pages, white paper submitted to the Galactic Neighborhood (GAN) Panel

[Updated 03/09/09. Added the following White Paper.]

A complete view of galaxy evolution: panchromatic luminosity functions and the generation of metals
Andrew W. Blain, et al, arXiv:0903.1272 [pdf]
Comments: A whitepaper submitted on 15th February 2009 in response to the call from the Astro2010 panel:; uploaded as an 8-page pdf file

[Updated 03/11/09. Added the following White Paper.]

A Proposal for a Renewed Research Emphasis in Astrophysical and Celestial Dynamics
D. J. Scheeres, et al, arXiv:0903.1650 [pdf, other]
Comments: 6 pp. White Paper submitted for the 2010 Decadal Survey, to panels PSF, SSE, GAN, & GCT

Tuesday, March 03, 2009

Fiddling with the blog layout

Mr Moto is out. Minima Stretch is in, as I prefer the extra width compared to the overly-restrictive fixed width blogger styles. Title, banner and font colors still need some work.