Thursday. Xun is doing a good job with the Journal Club, it seems. Dominique posted too!
1204.5474
The influence of stellar-dynamical ejections and collisions on the relation between the maximum-star and star-cluster-mass
Oh, Kroupa
N-body of your star cluster models to study the dynamical influence (ejection of the most massive star in the cluster) on the current relation between the maximum-stellar-mass and the star-cluster-mass. Vary initial parameters (half-mass radius, binary fraction, mass segregation). Massive binaries with two different pairing methods. Low mass clusters (1000 Msun): no "most massive" star escapes the cluster within 3 Myr. For small sized clusters (half-mass radius = 0.3 pc) with higher density eject their most massive star within 3 Myr. Dynamical effects hardly influence the observational maximum-stellar-mass -- cluster-mass relation.
1204.5478
The observed neutron star mass distribution as a probe of the supernova explosion mechanism
Pejcha, Thompson, Kochanek
The observed distribution of NS masses reflects the physics of core-collapse supernova explosions and the structure of the massive stars that produce them at the end of their evolution. Bayesian analysis for theoretical to observational comparison. Models with standard binary mass ratio distributions strongly preferred over independently picking the masses from they initial mass function (strength of influence depends on current assumptions for ID the remnants of the primary and secondary stars). NS formation models with no mass fallback favored because they reduce the dispersion in NS masses. The double NS system masses thus directly point to the mass coordinate where the supernova explosion was initiated, making them an excellent probe of the supernova explosion mechanism. Assume no fallback, vary the mass coordinate separating the remnant and the NSe ejecta, find that for the solar metallicity stars the explosion most likely developed at the edge of the Fe core at a specific entropy of about 2.8 k_B. The primary limitations of study are the poor knowledge of the SNe explosion mechanism and the lack of broad range of SN model explosions of LMC to solar metallicity.
1204.5480
Gas and dust in a z2.8 obscured quasar
Schumacher, Martinez-Sansigre, Lacy, Rawlings, Schinnerer
Molecular lines in unlensed, obscured quasar. Cl lines detected! (and CO) Significant fraction (30%) of the molecular gas is missed from the high-excitation line analysis [?]
1204.5482
The phenomenological approach to modeling the dark energy
Kunz
A mini-review. Describe LCDM, dark energy, modified gravity models in a fluid language: one background and two perturbation quantities.
1204.5487
Dark matter in 3d
Alves, El Hedri, Wacker
Relevance of directional detection experiments, method to extract the local DM phase space distribution from directional data. O(1000) events necessary to measure deviations from the standard halo model and constrain or measure the presence of anisotropies.
1204.5492
Galileons in the Sky
de Rham
Review the different frameworks where Galileon scalar fields seen to emerge e.g. in DGP, New Massive Gravity and Ghost-free massive gravity, emphasize relation with Lovelock invariant in braneworld models.
1204.5493
Observational evidence of the accelerated expansion of the universe
Astier, Pain
Review article of acceleration of the universe, and its observational evidences.
1204.5503
Discovery of Crystallized water ice in a silhouette disk in the M43 region
Terada, Tokunaga
As the title says.
1204.5505
Establishing homogeneity of the universe in the shadow of dark energy
Clarkson
Still don't know if the Copernican principle (that we are not at any special place in the universe) is true. How to reconcile? The abstract doesn't say, but the paper probably discusses it.
1204.5520
An integral field study of abundance gradients in nearby LIRGs
Rich, Torrey, Kewley, Dopita, Rupke
Results agree with the observed flattening of metallicity gradients as a merger progresses. Based on 9 LIRG observations. Agree with theoretical prediction that include chemical enrichment.
1204.5570
How long does it take to form a molecular cloud?
Clark, Glover, Klessen, Bonnell
Numerical simulation, formation of dense molecular clouds in colliding flows. Includes time-dependent model of H2 and CO chemistry. Clouds formed by collision of flows form stars, with SF beginning after 17 Myr in slower flow (6.8 km/s), but 4.4 Myr in faster flow (13.6 km/s). Results consistent with models of molecular cloud formation in which the clouds are dominated by "dark" molecular gas fora considerable proportion of their assembly history.
1204.5573
A second-order bias model for the logarithmic halo mass density
Jee, Park, Kim, Choi, Kim
Analytic model for the local bias for DM haloes in LCDM. 2nd order polynomial fit can describe the numerical relation between halo mass distribution and the underlying matter distribution well, when logarithmic density is used.
1204.5614
On the variations of fundamental constants and AGN feedback in the QSO host galaxy RXJ0911.4+0551 at z=2.79
Weiss et al
Within uncertainties, consistent with no variations of the fundamental constants.
1204.5626
Radial HI profiles at the periphery of galactic disks: the role of ionizing background radiation
Abramova
Observations of neutral H in spiral galaxies reveal a sharp cutoff in the radial density profile at some distance from the center. Use 22 galaxies, discuss: effect associated exclusively with external ionizing radiation (common assumption)? Show: before the surface density reaches 0.5 Msun/pc2 (the same for galaxies of different types), it is hard to expect the gas to be fully ionized by background radiation. 2/13 of the galaxies with a sharp drop in the HI profile can actually be caused by ionization. For the rest, the observed cutoff in the radial HI profile is closer to the center than if it was a consequence of ionization by background radiation and, therefore, it should be caused by other factors.
1204.5632
Career situation of female astronomers in Germany
Fohlmeister, Helling
Women astronomers from all academic levels (doctoral to professors) + those who left the field. Networking and human support the most important factors for success. Students should carefully choose their supervisor and collect practical knowledge abroad. Prejudices abundant (discriminating). Reasons why women are more likely than men to quit astronomy identified. Give recommendations to young students.
1204.5659
Star formation laws: the effects of gas cloud sampling
Calzetti, Liu, Koda
Sampling effects on scales a few times larger than the size of the largest molecular clouds, can affect functional shape of star formation-molecular gas density relation.
* Chaplygin gas: a hypothetical substance that satisfies and exotic equation of state in the form p = -A * rho^-alpha, with alpha=1, and A is a positive constant. Generalized Chaplygin gas has 0<a<=1.
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