1307.0011
Virial scaling of galaxies in clusters: bright to faint is cool to hot
Wu, Hahn, Evrard, Wechslter, Dolag
Combine galaxy tracers from high-resolution N-body and hydrodynamical simulations; present a consistent picture of the behavior of galaxy velocities in massive clusters. In haloes above 1e14 Msun, the brightest satellite galaxies are slightly cooler compared to the dark matter, while fainter satellites are hotter. [hot/cool in terms of their velocities?] Within the virial radius of a cluster, the mean velocity dispersion based on the 100 brightest galaxies is a factor of 1.046 higher than that of the DM (corresponding to a 10-15 % bias in the dynamical mass estimate) while that based on only the 5 brightest galaxies os 0.86. These trends are approximately independent of redshift. The velocity structure is sensitive to the modeling of galaxies in clusters, indicative of the complex interplay of tidal stripping, dynamical friction, and merging. Velocity dispersions derived from instantaneous subhalo properties are larger than those employing either peak subhalo properties or hydrodynamical galaxy tracers. The latter two methods are consistent, implying that stacked spectroscopic analysis of cluster samples should, after correction for projection, show a trend toward slightly higher velocities when fainter galaxies are included, with an unbiased measure of dark matter velocity dispersion coming from approximately 30 galaxies per cluster. Show evidence that the velocity distribution function of bright galaxies near the cluster center has a low-velocity tail due to strong dynamical friction. [luminosity and friction related? is luminosity proxy for size?]
1307.0136
Spin-orbit evolution of Mercury revisited
Noyelles, et al
Mercury is locked into the 3:2 spin-orbit resonance. Its rotation period, 58 days, is exactly 2/3 of its orbital period. It is accepted that the eccentricity of Mercury (0.206) favors the trapping into this resonance. How did the capture take place? A recent study by Makarov has shown that entrapment into this resonance is certain if the eccentricity is larger than 0.2, provided that a realistic tidal model based on Darwin-Kaula expansion of the tidal torque is used, including both the elastic rebound and the anelastic creep of solids. Revisit the scenario of Mercury's capture into the supersynchronous spin-orbit resonances. Study based on realistic model of tidal friction in solids, that takes into account the rheology and the self-gravitation of the planet. Used to determine the likely spin state of the planet GJ581d; also to study the tidal spin-down and to find the likely end-state of a Mercury-like planet with its eccentricity fixed. Consider evolution of Mercury's eccentricity. Find that the realistic tidal model, as opposed to the constant time lag and constant phase lag models, changes dramatically the statistics of the probably final spin-orbit states. After only one crossing of the 3:2 resonance this resonance becomes the most probably end-state. If a capture into any resonance takes place, the capture is final, several crossings of the same state being forbidden. Within the model the trapping of Mercury happens much faster than previously believed. The swift capture justifies treatment of Mercury as a homogeneous, unstratified body whose liquid core had not yet formed by the time of trapping.
1307.0545
The VIMOS VLT Deep Survey final data release: a spectroscopic sample of 35016 galaxies and AGN out to z~6.7 selected with 17.5<=i_{AB}<=24.7
Le Fevre, ... Ilbert, ... et al
As the title says, in areas 0.142 to 8.7 sq degs, and volumes from 0.5e6 to 1e7 Mpc^3/h^3. Selected samples of galaxies based solely on their i-band magnitude reaching i_{AB}=24.75. Spectra have been obtained with VIMOS on the ESO_VLT, integrating 0.75h, 4.5h and 18h for the Wide, Deep, and Ultra-Deep nested surveys. A total of 1263 galaxies have been re-observed independently within the VVDS, and from the VIPERS and MSSIV surveys. They are used to establish the redshift measurements reliability, to assess completeness, and to provide a weighting scheme taking into account the survey selection function. Describe the main properties of the VVDS samples, and the VVDS is compared to other spectroscopic surveys. In total obtain spectroscopic redshifts for 34594 galaxies, 422 type I AGN, ~561 in 2<z<3 and 468 with z>3, and specific populations like LAE identified out to z=6.62. Show that the VVDS occupies a unique place in the parameter space defined by area, depth, redshift coverage, and number of spectra. The VVDS provides a comprehensive survey of the distant universe, covering all epochs since z, or more than 12 Gyr of cosmic time, with a uniform selection, the largest such sample to date. A wealth of science results derived from the VVDS have shed new light on the evolution of galaxies and AGN, and their distribtion in space, over this large cosmic time. A final public release of the complete VVDS spectroscopic redshift sample is available at http://cesam.lam.fr/vvds.
1307.0712
The interstellar medium white paper
Burton, et al
The ISM is the engine room for galactic evolution. While much is known about the conditions within the ISM, many important areas regarding the formation and evolution of the various phases of the ISM leading to SF, and its role in important astrophysical processes, remain to be explained. This paper discusses several of the fundamental science problems, placing them in context with current activities and capabilities, as well as the future capabilities that are needed to progress them in the decade ahead. Particular science programs outline in this White Paper include the formation of molecular clouds, the ISM of the Galactic nucleus, the origin of gamma-rays and cosmic rays, high mass star and cluster formation, the dense molecular medium and complex organic molecules in space.
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