## Thursday, December 31, 2009

### Interesting Astrophysics: Dec 21 to Dec 31, 2009

The final edition of Interesting Astrophysics for 2009 is as diverse as ever. Of particular note, a classic superwind in the "8 o'clock arc" at z~2.7 (Dessauges-Zavadsky et al), a sample of galaxy groups analogous to our own Local Group (Marino et al), stellar wind mass loss rates in hot stars (Lucy et al), and astrobiology (Cirkovic et al).

Galaxies and Starbursts

Galaxy Evolution in Local Group Analogs. I. A GALEX study of nearby groups
A. Marino, L. Bianchi, R. Rampazzo, L.M. Buson, D. Bettoni,
Comments: 20 pages, 13 figures, accepted for publication in Astronomy and Astrophysics

Rest-frame ultraviolet spectrum of the gravitationally lensed galaxy the 8 o'clock arc': stellar and interstellar medium properties
M. Dessauges-Zavadsky, S. D'Odorico, D. Schaerer, A. Modigliani, C. Tapken, J. Vernet,
Comments: 17 pages, 10 figures, A&amp;A, accepted

From their abstract: "We present the first detailed analysis of the rest-frame UV spectrum of the gravitationally lensed Lyman break galaxy (LBG), the 8 o'clock arc'. The spectrum of the 8 o'clock arc is rich in stellar and interstellar medium (ISM) features, and presents several similarities to the well-known MS1512-cB58 LBG. ... The ISM lines extend over ~1000 km/s and have their peak optical depth blueshifted relative to the stars, implying gas outflows of about -120 km/s. The Ly-alpha line is dominated by a damped absorption profile on top of which is superposed a weak emission, redshifted relative to the ISM lines by about +690 km/s and resulting from multiply backscattered Ly-alpha photons emitted in the HII region surrounded by the cold, expanding ISM shell."

Luminosity-Metallicity Relations for Blue Compact Dwarf Galaxies in the Optical and Near-Infrared
Yinghe Zhao, Yu Gao, Qiusheng Gu,
Comments: 32 pages, 7 figures, accepted for publication in the Astrophysical Journal

Black Holes and AGN

Infrared Diagnostics for the Extended 12 micron Sample of Seyferts
Stefi A. Baum, Jack F. Gallimore, Christopher P. O'Dea, Catherine L. Buchanan, Jacob Noel-Storr, David J. Axon, Andy Robinson, Moshe Elitzur, Meghan Dorn, Shawn Staudaher, Martin Elvis,

Note to self: this paper deals with the correlations within the sample, but does not name the individual members of the sample.

Numerical Astrophysics and Hydrodynamics

Kristopher Yirak, Adam Frank, Andrew J. Cunningham,
Comments: 24 pages, 7 figures. Submitted to the Astrophysical Journal

They find that a fixed number of cells per radius does not lead to convergence in simulations of radiatively cooling clumps. They present alternative prescriptions for assessing numerical convergence.

X-ray astronomy

A wide field X-ray telescope for astronomical survey purposes: from theory to practice
P. Conconi, S. Campana, G. Tagliaferri, G. Pareschi, O. Citterio, V. Cotroneo, L. Proserpio, M. Civitani,

Stars, Supernovae and Planets

Mass fluxes for hot stars
L.B. Lucy,
Comments: Submitted to A&amp;A; 6 pages, 5 figures; second revision

Comprehensive Photometric Histories of All Known Galactic Recurrent Novae
Comments: ApJSupp in press, 273 pages, 34 tables, 71 figures

Note the size of the paper! That is definitely a labor of love.

3D simulations of supernova remnants evolution including non-linear particle acceleration
Gilles Ferrand, Anne Decourchelle, Jean Ballet, Romain Teyssier, Federico Fraschetti,
Comments: accepted for publication in A&A (final version)

PopStar Evolutionary Synthesis Models II: Optical emission-line spectra from Giant Hii regions
M.L. Martín-Manjón, M.L. García-Vargas, M. Mollá, A.I. Díaz,
Comments: 20 pages, 26 figures, accepted for publication in MNRAS Main Journal

Including All the Lines
Robert L. Kurucz,
Comments: 9 pages, no figures. Presented at "Dimitrifest" conference in Boulder, Colorado, March 30 - April 3, 2009
Journal-ref: Recent Directions in Astrophysical Quantitative Spectroscopy and Radiation Hydrodynamics. Edited by I. Hubeny, J.M. Stone, K. MacGregor, and K. Werner. AIP Conference Proceedings 1171, pp. 43-51, 2009

Astrobiology

Galactic Punctuated Equilibrium: How to Undermine Carter's Anthropic Argument in Astrobiology
Milan M. Cirkovic, Branislav Vukotic, Ivana Dragicevic,
Journal-ref: Published in Astrobiology, 2009, Volume 9, Issue 5, pp. 491-501

## Tuesday, December 29, 2009

### Where is the joy in research?

Dennis Overbye has a rather odd essay in the NYT: "The Joy of Physics Isn’t in the Results, but in the Search Itself ." It starts off reading as a conventional justification for pure research based on the unanticipated but fundamentally useful technological products it produces, products that applied scientific or technological research would not have produced. You know the things: hypertext and the WWW, digital camera sensors, MRI and PET scanners, Velcro, pens that write when upside down, memory foam beds.

But then it veers off to tackle, as far as I can tell, the slow and bumpy road along the path of scientific progress from Overbye's perspective as a science writer in 2009. The pre-servicing mission Hubble contrasted with post servicing mission glory, the Large Hadron Collider's commissioning woes, and the pre-announcement hype of CDMS-2's decidedly ambiguous one (or two, if you're generous) sigma pseudo result. This is more in line with the essay's title.

I presume that Overbye's point was to highlight that the scientific method is not all about predictable results that appear in a regular and preplanned way. That both the results and process of science are unpredictable, and that's where the "joy" of it lies.

Its all very well, admirable even, for a science writer to tackle societies naive and preconceived views of how science works, but I must say I think Overbye's essay veers to much in the opposite direction to ignore the many years of routine operation by telescopes (the result of careful planning and hard work) and particle colliders, where experiments are planned and go roughly as expected. Unanticipated surprises happen, but the surprise us because they're rare and contrast so vividly with the larger edifice of scientific progress built slow accumulation and refinement.

Returning to the title of Overbye essay, I'd agree that doing science is fun. Seeing or discovering things that no-one else has ever seen or thought is a thrill. The mental challenge itself is pleasurable, even when you're treading scientific ground where others have gone before. But getting a result - answering a question - even if it isn't the answer you expected, is the payoff and culmination of all the hard work. So some of the joy of physics is certainly in the search, but a lot of it is in getting results.

## Friday, December 18, 2009

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

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

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,
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,
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,
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,
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,
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, 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,
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,
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,

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

## Tuesday, December 15, 2009

### XMM-Newton AO-9 accepted proposals announced

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.

## Thursday, December 10, 2009

### Happy 10th birthday, XMM-Newton

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.

## Friday, December 04, 2009

### Interesting Astrophysics: Nov 23 to Dec 04, 2009

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
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,
Comments: 28 pages, 22 figures, 7 tables, to be published in Astronomical Journal

Forty Years of Research on Isolated Galaxies
J. W. Sulentic,
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,
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,
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,
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,
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,
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,
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,
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,

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,
Comments: Accepted for publication in The Astrophysical Journal. 39 pages, 15 figures

Stars, Supernovae and Planets

Introduction to nuclear astrophysics
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,
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,
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,
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,

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

## Wednesday, December 02, 2009

### BBC discusses costs of ESA Cosmic Vision contenders

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!