1209.3013
On the lack of evolution in galaxy star formation efficiency
Behroozi, Wechsler, Conroy
Calculate instantaneous efficiency of galaxy SF (SFR divided by baryon accretion rate) using reconstructed SFH, from z=8 to 0. Efficiency probes a peak near a characteristic halo mass of 1e11.7 Msun, which coincides with predictions for the mass scale relevant to virial shock heating of accreted gas. Above the characteristic halo mass, efficiency falls off as the mass to the -4/3 power; blow this, the efficiency falls off at an average scaling of mass to the 2/3 power. By comparison, the shape and normalization of the efficiency change vary little since z=4. Time independent SF efficiency explains the shape of cosmic SFR since z=4 in terms of DM accretion rates. Rise in cosmic SF from early times until z=2 is sensitive to galaxy formation efficiency. Mass dependence of efficiency strongly limits where most SF occurs, with the result that 2/3 or all SF has occurred inside halos within a factor of 3 of the characteristic mass, a range that includes the mass of the MW.
1209.3015
Stringent and robust constraints on the dark matter annihilation cross section from the region of the galactic center
Hooper, Kelso, Queiroz
GC constraint just as strong as dwarf spheroidals. Robustly rule out DM particles with M<285 GeV.
1209.3016
No clear submillimetre signature of suppressed star formation amongst X-ray luminous AGNs
Harrison et al
Herschel-SPIRE submillimeter observations that support AGN suppresses SF? Extend these results to achieve an order of magnitude improvement in the number of sources, analysis finds no strong evidence for suppressed SF for Lx>1e44 erg/s at z=1-3. The mean SFRs were constant over the broad X-ray luminosity range. The previous CDF-N results were likely due to low number statistics. Discuss results in the context of current theoretical models, suggest that it will be challenging to see the signature of suppressed SF simply on the basis of an X-ray luminosity threshold.
1209.3018
Dark matter halo merger histories beyond cold dark matter: I - methods and application to warm dark matter
Bension ... Cole, Moustakas, ... Frenk, et al
Methodology to accurately compute halo mass functions, progenitor mass functions, merger rates and merger trees in non-cold dark matter universes using a self-consistent treatment of the generalized extended Press-Schechter formalism. Permits rapid exploration of the subhalo population of galactic haloes in dark matter models with a variety of different particle properties or universes with rolling, truncated, or more complicated power spectra. Compare with analytically derived mass function/merger histories with WDM N-body sims and find excellent agreement. Coarse-grained statistics such as the mass accretion history of haloes can be almost indistinguishable between cold and warm dark matter cases; but the halo mass function and progenitor MFs differ significantly (WDM suppressed below the free-streaming scale of the DM.
1209.3033
Radio astronomy with the lunar lander: opening up the last unexplored frequency regime
Wolt et al
Broadband (1kHz-100MHz) tripole antenna envisaged to be place on the European Lunar Lander located at the Lunar South Pole allows for sensitive measurements of the exosphere and ionosphere, and their interaction with the Earths magnetosphere, solar particles, wind and CMEs and studies of radio communication on the moon (for future lunar human and science exploration).
1209.3041
The low-temerature nuclear spin equilibrium of H3+ in collisions with H2
Grussie et al
Difference in nuclear spin excitation temperatures of the 2 species (in space). Measure the steady-state ortho/para ratio of H3_ in collisions with H2 molecules in a temperature-variable RF ion trap between 45-100K, results close to the expected thermal outcome, agree very well with a previous micro-canonical model.
1209.3072
Estimation of halo ellipticity using spin-3 flexion
Er, Bartelmann
The spin-3 gravitational flexion can add useful information on the ellipticity of lensing haloes. General formalism to decompose general fields in to radial and tangential components, the ratio of the tangential and radial flexion components directly estimates the lens ellipticity. Any centroid offset will significantly bias the estimate, which can be used to determine the center of the lens halo.
1209.3114
eROSITA science book: mapping the structure of the energetic universe
Merloni ... Böhringer, ... Reiprich,... et al
eROSITAis the primary instrument on the Russian SRG mission, launch ~2014. Deep survey of the entire X-ray sky. 20x more sensitive than the ROSAT all-sky survey in soft X-ray (0.5-2 keV); in hard (2-10keV) it will provide the first ever true imaging survey of the sky at those energies. Science: detection of very large samples (1e5 objects) of galaxy clusters out to z>1, for cosmological model testing and LSS studies. Also expected to yield 3e6 AGN samples (both obscured and un-obscured) in the cosmic structure; accreting binaries, active stars, and diffuse emission within the Galaxy, as well as SS bodies that emit X-rays via the charge exchange process. Deep imaging survey at high spectral resolution, with its scanning strategy sensitive to a range of variability timescales from tens of seconds to years, will open up a vast discovery space for study of rare, unpredicted, or unpredictable high-ernergy astrophysical phenomena. Present main scientific goals of the mission, with strong emphasis on the early survey phases.
1209.3142
Anti-lensing: the bright side of voids
Bolejko, Clarkson, Maartens, Bacon, Meures, Beynon
The standard "demagnification effect" by voids is swamped by a relativistic Doppler term that is typically neglected. Objects on the far size of a void are brighter than they would be otherwise. Thus the local dynamics of matter in and near the void is crucial and is only captured by the full relativistic lensing convergence.
1209.3213
Herschel-ATLAS/GAMA: spatial clustering of low-redshift sub-mm galaxies
van Kampen et al
Measured spatial clustering length r_0 is comparable to that of optically-selected, moderately star-formaing (blue) galaxies.
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