Monday, August 31, 2009

Papers: Quality Versus Quantity

Amusing SMBC comic. Because we all suspect our competitors think this way...

Friday, August 28, 2009

Interesting Astrophysics: Aug 14 - 28

A broad range of generally interesting papers have appeared over the last two weeks, all from the arXiv preprint server. Of particular note are a couple of papers based on Spitzer Space Telescope observations of galaxies (Satyapal et al; Bernard-Salas et al), radio observations of CO and HI in nearby starbursts (Israel; Shafi et al), and a review of nearby galaxy properties by Blanton & Moustakas.

Galaxies and Starbursts

The Incidence of Active Galactic Nuclei in Pure Disk Galaxies: The Spitzer View
S. Satyapal, T. Boeker, W. Mcalpine, M. Gliozzi, N. P. Abel, T. Heckman, arXiv:0908.1820 [ps, pdf, other]
Comments: 17 pages, 8 figures, accepted for publication in ApJ

Ultraluminous X-ray Sources in Interacting Galaxies
Douglas A. Swartz, arXiv:0908.2459 [ps, pdf, other]
Comments: 5 pages to appear in the Proceedings of the Galaxy Wars: Stellar Populations and Star Formation in Interacting Galaxies Conference

The Spatially Resolved Star Formation Law from Integral Field Spectroscopy: VIRUS-P Observations of NGC 5194
Guillermo A. Blanc, Amanda Heiderman, Karl Gebhardt, Neal J. Evans II, Joshua Adams, arXiv:0908.2810 [ps, pdf, other]
Comments: 23 pages, 19 figures, 14 pages of tables. Accepted for publication in ApJ

From the abstract: "We present a new method for fitting the Star Formation Law (SFL), which includes the intrinsic scatter in the relation as a free parameter, allows the inclusion of non-detections, and is free of the systematics involved in performing linear correlations over incomplete data in logarithmic space."

A Spitzer high resolution mid-infrared spectral atlas of starburst galaxies
J. Bernard-Salas, H.W.W. Spoon, V. Charmandaris, V. Lebouteiller, D. Farrah, D.Devost, B.R. Brandl, Yanling Wu, L. Armus, L. Hao, G.C. Sloan, D.Weedman, J.R. Houck, arXiv:0908.2812 [ps, pdf, other]
Comments: 25 pages (emulate apj), 6 tables, 14 figures, Accepted for publication in ApJS

From the abstract: "We use the fine-structure lines to derive the abundance of neon and sulfur for 14 objects where the HI 7-6 line is detected. .... We have combined the spectra of all the pure starburst objects to create a high S/N template, which is available to the community."

Physical properties and environments of nearby galaxies
Michael R. Blanton, John Moustakas, arXiv:0908.3017 [ps, pdf, other]

Comments: Annual Reviews of Astronomy and Astrophysics, Vol. 47, in press, full resolution version at this http URL

The Extremely Young Star Cluster Population In Haro 11
Angela Adamo, Göran Östlin, Erik Zackrisson, Matthew Hayes, arXiv:0908.3107 [ps, pdf, other]
Comments: 4 pages, 3 figures. To appear in the proceedings of "Galaxy Wars: Stellar Populations and Star Formation in Interacting Galaxies" (Tennessee, July 09)

The Automatic Galaxy Collision Software
Beverly J. Smith, Chris Carver, Phillip Pfeiffer, Sam Perkins, Jason Barkanic, Steve Fritts, Derek Southerland, Dinikar Manchikalapudi, Matt Baker, John Luckey, Coral Franklin, Amanda Moffett, Curtis Struck, arXiv:0908.3478 [ps, pdf, other]
To appear in the Proceedings of the Galaxy Wars: Stellar Populations and Star Formation in Interacting Galaxies Conference

A composite K-band Luminosity Function for Cluster Galaxies
Roberto De Propris, Daniel Christlein, arXiv:0908.3520 [ps, pdf, other]
Comments: 3 pages, 1 figure, Astronomische Nachrichten (JENAM 2008 Symposium 6)

CI and CO in nearby galaxy centers. The star-burst galaxies NGC 278, NGC 660, NGC 3628, NGC 4631, and NGC 4666
F.P. Israel, arXiv:0908.3586 [ps, pdf, other]
Comments: Accepted for publication in Astronomy & Astrophysics

Note to self: NGC 3628 data and discussion.

The Hot and Cold Outflows of NGC 3079
N. Shafi, R. Morganti, T. Oosterloo, R. Booth, arXiv:0908.3979 [ps, pdf, other]
Comments: To appear in the Proceedings of the "Galaxy Wars: Stellar Populations and Star Formation in Interacting Galaxies" Conference, B. Smith, N. Bastian, J. Higdon and S. Higdon eds, in press

Outflowing HI within the central 1 kpc of NGC 3079.

High Energy Astrophysics

Numerical computation of isotropic Compton scattering
R. Belmont, arXiv:0908.2705 [ps, pdf, other]
Comments: 11 pages. Accepted for publication in A&A

Numerical Astrophysics and Hydrodynamics

Two-Fluid MHD Simulations of Converging Hi Flows in the Interstellar Medium. II: Are Molecular Clouds Generated Directly from Warm Neutral Medium?
Tsuyoshi Inoue, Shu-ichiro Inutsuka, arXiv:0908.3701 [ps, pdf, other]
Comments: 9 pages, 8 figures, accepted by ApJ

Magnetic field in dwarf galaxies: building block for a Cosmic Dynamo?
Yohan Dubois, Romain Teyssier, arXiv:0908.3862 [ps, pdf, other]
Comments: 16 pages, 10 figures, submitted to A&A

I'll need to have a closer look at this paper. From their abstract: "We are testing whether dwarf galaxies are good candidates to explain the enrichment of the IGM: after their discs form and trigger galactic dynamos, supernova feedback will launch strong winds, expelling magnetic field lines in the IGM. We have performed MHD simulations of an isolated dwarf galaxy, forming self-consistently inside a cooling halo. Using the RAMSES code, we have for the first time simulated the formation of a magnetised supernova-driven galactic outflow."

Stars, Supernovae and Planets

Seeking Core-Collapse Supernova Progenitors in Pre-Explosion Images
Douglas C. Leonard, arXiv:0908.1812 [ps, pdf, other]
Comments: 10 pages, to appear in "Hot And Cool: Bridging Gaps in Massive Star Evolution", C. Leitherer, Ph. D. Bennett, P. W. Morris, & J. Th. van Loon (eds.), ASP Conf. Ser

Measuring The Mass Loss Evolution at The Tip of The Asymptotic Giant Branch
C. Sandin, M. M. Roth, D. Schönberner, arXiv:0908.2432 [ps, pdf, other]
Comments: 6 pages, submitted, workshop in honour of Agnes Acker, Legacies of the Macquarie/AAO/Strasbourg Halpha Planetary Nebula project, eds. Q.Parker and D.Frew, PASA

Radio observations of colliding winds in massive stars
Sean M. Dougherty, arXiv:0908.2660 [ps, pdf, other]
Comments: Invited review at HEPIMS Workshop (Jaen 2009); 12 pages, 6 figures, to appear in PASP

Accurate masses and radii of normal stars: modern results and applications
G. Torres, J. Andersen, A. Gimenez, arXiv:0908.2624 [ps, pdf, other]
56 pages including figures and tables. To appear in The Astronomy and Astrophysics Review. Ascii versions of the tables will appear in the online version of the article

Great review, impressive results. In all the flash and bang associated with popular subjects like cosmology, black holes, gamma ray bursts and planets it is easy to forget that stars are still of fundamental importance, and that there is still much we don't know or need to know better. I'm glad to see people still do this kind of work.


The mystery of the telescopes in Jan Brueghel the Elder's paintings
Paolo Molaro, Pierluigi Selvelli, arXiv:0908.2696 [ps, pdf, other]
Comments: 4 pages, 2 figures Proceedings 53 SAIt 2009, Pisa

Thursday, August 27, 2009

Astroblog: "Unscientific America" and the case of Pluto

Ian Musgrave has a great post ("Unscientific America" and the case of Pluto) that lays out the scientific reasons why Pluto was ultimately demoted from full planet status.

The fuss some people put up about Pluto's demotion was the basis for Mooney & Kirshenbaum's opening argument in their recent book "Unscientific America." M&K portray the antagonism toward this decision as an example of scientist's detachment and inability to communicate with the public, before going onto to blame general scientific illiteracy on aloof snobbish scientists.:

The furor over Pluto is just one particularly colorful example of the rift that exists today between the world of science and the rest of our society.
Musgrave does a great job of explaining the scientific events leading up to the IAU's "controversial" 2006 decision, and even some of the social events: I had forgotten completely about the mini-fuss in 2001 associated with the Hayden Planetarium not including Pluto as a planet. I certainly wasn't aware that Neil deGrasse Tyson received hate mail from 3rd graders for that!

There is one issue that Musgrave touches on but does not explore as deeply as I think it deserves:
Astronomers did forsee an outcry from the public, and they did care (especially as several of their own number had a strong attachment to Pluto s [sic] a planet). [emphasis mine]
M&K's thesis rests most easily on the assumption that the Pluto controversy was a simple case of clueless scientists versus an offended public.

But this simple picture ignores the internal conflict within the astronomical community that the media played upon (aided by those who disagreed with the results of the IAU vote). I remember getting emails from astronomer colleagues asking for signatures on petitions protesting the outcome of the IAU vote. That internal discord was certainly picked up by, or fed to, the media given their love for reporting controversy.

Not only do different scientists have strong personal opinions regarding their favourite objects, but there were strong political/financial reasons that would lead some to oppose Pluto's demotion. For example, its not hard to guess why many of the people associated with New Horizons (the fast Pluto fly-by mission) might not like Pluto being demoted (A mission to the only planet we haven't yet visited becomes rather less pressing when Pluto is now only one of many Minor Planets). In if NASA budgets weren't strained the justification for a mission and its funding matter a lot. I can certainly empathize with the scientists who oppose the IAU decision, even if I don't agree with them.

Given that Pluto "controversy" was fed or hyped to some significant extent by a genuine minority of disaffected astronomers it is a bad example of the (supposed) difficulties scientist's have with communicating with the public, and hence a bad foundation for M+K to start their book.

Certainly a better example of controversies where public attitude fail to reflect scientific consensus would be climate change, or stem cells. But there it is also obvious that whatever the limitations of scientist's own public outreach are, the majority of the opposition to the scientific consensus is deliberately fed by groups or organizations with their own socio-political agendas.

And that, I suspect, does not conform to the narrative M+K wish to present.

Friday, August 14, 2009

Happy Birthday Ørsted! (and Electromagnestism)

Today (August 14th) is the 232nd birthday of Hans Christian Ørsted, whose experimental work in 1820 discovered that electric currents generate magnetic fields, and hence can be said to be the discovery of electromagnetism (one of the four fundamental forces).

Google's logo for the day honors
Ørsted's birth by showing (in essence) his experimental set-up. Though I suspect most people who see it will think it is a bomb.

Thursday, August 13, 2009

Interesting Astrophysics: 03-13 Aug, 2009

In addition to the usual crop of galaxy-related papers I tend to find most interesting there have been a rash of both interesting AGN and massive star stellar wind papers. Papers of particular note are Harris & Zaritsky (star formation history of the LMC), Behar (Seyfert galaxy outflows) and three papers by Parkin et. al., Pittard, and Owocki (all related to stellar wind theory).

Galaxies and Starbursts

The Star Formation History of the Large Magellanic Cloud
Jason Harris, Dennis Zaritsky, arXiv:0908.1422 [ps, pdf, other]
Comments: 20 pages, with color figures. Accepted for publication in AJ

Dust-Corrected Star Formation Rates of Galaxies. I. Combinations of H-alpha and Infrared Tracers
Robert C. Kennicutt, Jr., Cai-Na Hao, Daniela Calzetti, John Moustakas, Daniel A. Dale, George Bendo, Charles W. Engelbracht, Benjamin D. Johnson, Janice C. Lee, arXiv:0908.0203 [ps, pdf, other]
Comments: 75 pages, 22 figures, accepted for publication in The Astrophysical Journal

The properties of the stellar populations in ULIRGs I: sample, data and spectral synthesis modelling
J.Rodriguez-Zaurin, C.N.Tadhunter, R.M.Gonzalez-Delgado, arXiv:0908.0269 [ps, pdf, other]
Comments: accepted for publication in MNRAS

Quantified Morphology of HI Disks in the Universe
B. W. Holwerda, W. J. G. de Blok, A. Bouchard, S-L. Blyth, K. van der Heyden, N. Prizkal, arXiv:0908.0693 [ps, pdf, other]
Comments: 6 pages, 3 figures, proceeding of the conference "Panoramic Radio Astronomy: Wide-field 1-2 GHz research on galaxy evolution", June 02 - 05 2009, Groningen

Black Holes and AGN

The OPTX Project III: X-ray versus Optical Spectral Type for AGNs
L. Trouille, A. J. Barger, L. L. Cowie, Y. Yang, R. F. Mushotzky, arXiv:0908.0002 [ps, pdf, other]
Comments: Accepted for publication in The Astrophysical Journal. 11 pages, 8 figures, 4 tables

Constraining the Spin of the Black Hole in Fairall 9 with Suzaku
S. Schmoll, J. M. Miller, M. Volonteri, E. Cackett, C. S. Reynolds, A. C. Fabian, L. W. Brenneman, G. Miniutti, L. C. Gallo, arXiv:0908.0013 [ps, pdf, other]
Comments: Accepted for publication in ApJ

Isotropic Mid-Infrared Emission from the Central 100 pc of Active Galaxies
N. A. Levenson, J. T. Radomski, C. Packham, R. E. Mason, J. J. Schaefer, C. M. Telesco, arXiv:0908.0036 [ps, pdf, other]
Comments: 10 pages, 5 figures; accepted for publication in ApJ

AGN/starburst connection in action: the half million second RGS spectrum of NGC1365
M.Guainazzi, G.Risaliti, A.Nucita, Junfeng Wang, S.Bianchi, R.Soria, A.Zezas, arXiv:0908.0268 [ps, pdf, other]
Comments: Accepted for publication in Astronomy & Astrophysics, 13 pages, 10 figures

Density Profiles in Seyfert Outflows
Ehud Behar, arXiv:0908.0539 [ps, pdf, other]
Comments: submitted to ApJ

A 100-kpc inverse Compton X-ray halo around 4C60.07 at z=3.79
Ian Smail, B.D. Lehmer, R.J. Ivison, D.M. Alexander, R.G. Bower, J.A. Stevens, J.E. Geach, C.A. Scharf, K.E.K. Coppin, W.J.M. van Breugel, arXiv:0908.0819 [ps, pdf, other]
Comments: ApJL, in press

Stars, Supernovae and Planets

The interactions of winds from massive young stellar objects: X-ray emission, dynamics, and cavity evolution
E. R. Parkin, J. M. Pittard, M. G. Hoare, N. J. Wright, J. J. Drake, arXiv:0908.0468 [ps, pdf, other]
Comments: 19 pages, 14 figures, accepted for publication in MNRAS

3D models of radiatively driven colliding winds in massive O+O star binaries - II. Thermal radio to sub-mm emission
J. M. Pittard, arXiv:0908.1003 [ps, pdf, other]
Comments: 25 pages, 21 figures, accepted for publication in MNRAS

Radiation Hydrodynamics of Line-Driven Winds
Stan Owocki, arXiv:0908.1565 [ps, pdf, other]
Comments: 14 pages. to appear in "Recent Directions in Astrophysical Quantitative Spectroscopy and Radiation Hydrodynamics"

Wednesday, August 12, 2009

Stephen Hawking schools Investors Business Daily

Investors Business Daily, perhaps better known for exceptionally dishonest climate change denialism editorials, now presents conservatism's most cogent arguments against health care reform:

People such as scientist Stephen Hawking wouldn't have a chance in the U.K., where the National Health Service would say the life of this brilliant man, because of his physical handicaps, is essentially worthless.

Once the rest of the world had stopped laughing at Investors Business Daily it was left to Hawking to quietly state the obvious (as reported by Hugh Muir in the Guardian).
"I wouldn't be here today if it were not for the NHS," he told us. "I have received a large amount of high-quality treatment without which I would not have survived."
After being so rightly ridiculed for their stupidity IBD removed the offending passage from their editorial without having the intellectual ability to realise (or honesty to admit) that it invalidated the whole premise of their misinformed screed (redacted editorial here). Clearly they have never heard of the "No true Scotsman" fallacy either.