1206.4043
Environmental effects in the interaction and merging of galaxies in zCOSMOS survey
Kampczyk, Lilly, the zCOSMOS collaboration
Fraction of close pairs is 3x higher in the top density quartile than in the lowest one [duh]. Simulations show merger timescales to be largely independent of environment, so pair fractions observed translate into merger fractions. Galactic properties of close pairs can be explained by taking into account well-known effects of environment and changes caused by interactions. Latter responsible for irregular galaxies in pairs. Boost in SFR (2x-4x) for the closest pairs, but represent only 5% of integrated SF activity in the volume-limited sample. Effects of interactions strongest in lower density environments, which may introduce bias in merger studies. Excess of post-starburst galaxies and AGNs (both ~2x), early phases of interactions and merging are plausible candidates for environmental quenching.
1206.4045
The panchromatic Hubble Andromeda treasury I: Bright UV stars in the bulge of M31
Rosenfield, ... Lauer, Bell, Rix et al
Data supports UV bright sources in the bulge are likely hot (extreme) horizontal branch stars (EHB) and their progeny; highly concentrated radially, more so than the integrated UV or optical light.
1206.4046
Gas-rich mergers and feedback are ubiquitous amongst star bursting radio galaxies, as revealed by JVLA, IRAM PdBI and Herschel
Ivison et al
Radio observation of 2 z=3-3.5 FIR luminous radio galaxies. Evidence that significant energy is being deposited rapidly into the molecular gas via X-rays and/or mechanical('quasar-mode') feedback from the AGN, feedback that may lead to the cessation of SF on a timescale commensurate with that of the jet activity, <~10Myr.
1206.4047
LBT and Spitzer spectroscopy of star-forming galaxies at 1<z<3: Extinction and star formation rate indicators
Rujopakarn et al
Use 4 SL IR-luminous galaxies; augment with 3 lens galaxies. Use IR recombination with Halpha observations to probe the extinction Av, and test SFR indicators against FIR photometry (fit to SED). Av range from ~0 to 5.9 mag, SFR observations at z~2 must take extinction into account carefully. Large range of dust distribution scenarios. Without correction for extinction, the Halpha SFR indicator underestimates SFR. Individual SFR estimates based on 6.2 um PAH emission line luminosity do not show a systematic discrepancy with extinction, although ~0.2 dex scatter (which is considerable) observed.
1206.4048
The international deep planet survey I. the frequency of wide-orbint massive planets around A-stars
Vigan et al
Estimate fraction of A-stars having at least one massive planet (3-14 MJup) in the range 5-320 AU to be 5.9-18.8% (1 sigma) assuming flat distribution for the mass of the planets. Brown dwarf (15-75 MJup) smaller at 2-9%. From AO data.
1206.4049
Lightcone mock catalogues from semi-analytic models of galaxy formation - I. construction and application to the BzK color selection
Merson, et al
Method for constructing end-to-end mock galaxy catalogues using SAM of galaxy formation, applied to halo merger trees extracted from a cosmo N-body sim. Lightcone catalogues: galaxy is placed according to the epoch at which it first enters the past light cone of the observer, and incorporate the evolution of galaxy properties with cosmic time. Mock catalogue in reasonable agreement with observed number counts of all BzK galaxies (1.4<z<2.5 selection); >75% of model galaxies with K_AB<=23 and 1.4<z<2.5 should be selected with this technique.
1206.4050
Ultra-luminous supernovae as a new probe of the interstellar medium in distant galaxies
Berger et al
Pan-STARRS1 discovery and light curves; MMT follow-up, Gemini spectroscopy of ultra-luminous supernova (ULSN) at z=1.566. Broad absorption features (CII, SiIII), strong and narrow MgII and FeII absorption lines from ISM of the host galaxy. EW of FeII and MgII are high, but not as high as GRB host galaxy's. High UV continuum of host galaxy.
1206.4052
The clustering of H-alpha emitters at z=2.23 from HiZELS
Geach et al
Clustering analysis of 370 high-confidence H-alpha emitters (HAEs) at z=2.33 over two 1 sqdeg fields. Clustering correlation length of r0=3.7pm0.3 Mpc/h; corresponding halo mass is 1e11.7 Msun. Compare to GALFORM SAM for evolution, find broad agreement (predicts r0 = 4 Mpc/h). Construct HOD for HAEs.Supports broad picture that L* SF galaxies have been hosted by DM haloes with M<1e12 Msun/h since z~2, but with a board occupation distribution and clustering that is likely to be a strong function of luminosity.
1206.4055
Is there correlation between fine structure and dark energy comic dipoles?
Mariano, Perivolaropoulous
The dipoles seem to align (DE=SNe data, fine structure=quasar absorption data). Angular separation is 11.3 pm 11.8 degrees. Low probability for this alignment if everything is isotropic. Propose "extended topological quintessence" which naturally predicts spherical inhomogeneous distribution for both DE and fine structure constant.
1206.4057
The nature of hypervelocity stars and the time between their formation and ejection
Brown, Cohen, Geller, Kenyon
HVSS--if ejected by the central BH, then galactic center was forming stars ~200 Myr ago, and the progenitors of the HVSs took ~100 Myr to enter the BH's loss cone.
1206.4059
Rotating accretion flows: from infinity to the black hole
Li, Ostriker, Sunyaev
Use ZEUS code to run hydrosims of rotating, axisymmetric accretion flows with Bremsstahlung cooling, considering solutions with and without viscous angular momentum transport, and also electron thermal conduction. ...
1206.4060
The Spitzer extragalactic representative volume survey (SERVS): survey definition and goals
Mauduit et al
SERVS: 18 sq deg medium-deep survey at 3.6 and 4.5 microns of 5 highly observed astronomical fields (ELAINS-N1 and S1, Lockman Hole, CDFS and XMM-LSS). Enable study of galaxy evolution from z~5 to 0, put luminous quasars and galaxy clusters at z>1 into their cosmological context. Overlap with surveys of other bands (optical, NIR, FIR, sub millimeter, radio).
1206.4063
Heavily obscured quasar host galaxies at z~2 are disks, not major mergers
Schawinski, Simmons, Urry, Treister, Glikman
As the title says. 28 DOGs, only a few percent are major mergers, others are disk or disk-dominated. Suggests that secular processes are the predominant driver of massive BH growth (sample of heavily obscured quasars represents a significant fraction of the cosmic mass accretion on SMBH ). Suggest: coincidence of mergers and AGN activity is luminosity dependent, with only the most luminous quasars being triggered mostly by major mergers.
1206.4070
Distribution function approach to redshift space distortions, Part III: halos and galaxies
Okumura, Seljak, Desjacques
Power spectrum in z-space can be written as a sum of X-power spectra between number weighted velocity moments. Investigate the properties of these power spectra for simulated galaxies and DM haloes, compare them to the DM power spectra, generalizing the concept of the bias. Find: NL effects in realistic galaxy samples such as luminous red galaxies affect the redshift space clustering on very large scales: for example, the quadrupole moment is affected by 10% for k<0.1h/Mpc, which means that these effects need to be understood if we want to extract cosmological information from the z-space distortions.
1206.4088
Design of mirrors and apodization functions in phase-induced amplitude apodization (PIAA) systems
Cady
PIAA coronagraphs: for imaging exoplanets (Earth-like planets around Sun-like stars). Pair of mirror which reshape incident light without attenuation, coupled with one or more apodizers to mitigate diffraction effects or provide additional beam-shaping to produce a desired output profile.
1206.4188
Primordial black holes as a tool for constraining non-Gaussianity
Byrnes, Copeland, Green
Number of PBHs formed is sensitive to small changes in the shape of the tail of the fluctuation distribution, which depends on the non-Gaussianity present. Non-linearity parameters of order unity have significant impact on the PBH abundance. The sign of the non-Gaussianity is important. If PBHs are observed in the future, non-negligible negative f_nl would be ruled out. g_nl have an even larger effect on the number of PBHs formed than f_nl.
1206.4190
Debris from terrestrial planet formation: the Moon-forming collision
Jackson, Wyatt
Study the evolution of debris created in the giant impacts expected during the final stages of terrestrial planet formation. Follow dynamical evolution for 10 Myr: clump in the first few months, asymmetric ring for the first 10 kyr, and finally becoming an axisymmetric ring by about 1 Myr after the impact. By 10 Myr 20% of the particles have been accreted onto Earth and 17% onto Venus; 8% ejected by Jupiter and other bodies playing minor roles. Fate of debris also depends strongly on how fast it is collision ally depleted, which depends on the poorly constrained size distribution of the impact debris. If debris by mass is 30% mm/cm-sized vapor condensates and 70% boulders up to 500 km, the condensates deplete rapidly on 1kyr timescales, whereas the boulders deplete predominantly dynamically. Consider luminosity of dust within the boulder-debris distribution, find that the Moon-forming impact would have been readily detectable around other stars in Spitzer 24 um surveys for around 25 Myr after the impact (similar to hot dust systems). The vapor condensates produce a short-lived, optically thick spike of emission. Use these surveys to make an estimate of the fraction of stars that form terrestrial planets. Current terrestrial planet formation models invoke multiple giant impacts, the low fraction of 10-100 Myr stars found to have warm dust (~150 K) implies that T_TPF < 10%.
1206.4196
The matter bounce alternative to inflationary cosmology
Brandenberger
Bouncing cosmology with an initial matter-dominated phase of contraction during which scales which are currently probed with cosmological observations exit the Hubble radius provides a mechanism alternative to inflation for producing a nearly scale-invariant spectrum of cosmological perturbations. Disucss evolution of cosmological fluctuation in the matter bounce scenario; and observational signatures to distinguish them from inflationary scenario.
1206.4237
Similarities in populations of star clusters
Fall, Chandar
Compare mass functions and age distributions of star clusters in six well-studied galaxies: the MW, Magellanic clouds, M83, M51 and Antennae. Distributions are well represented by power laws. Mass and age distributions are approximately independent of each other. Minor differences among the exponents, at level close to the true uncertainties, but mostly similar for the different galaxy types---a "universal" mass function. Physical processes during formation and disruption of clusters, SF and feedback, subsequent stellar mass loss, and tidal interactions with passing molecular clouds. A full explanation will require additional information about the molecular clumps and star clusters in galaxies beyond the MW.
1206.4263
The VISTA deep extragalactic observations (VIDEO) survey
Jarvis et al
VIDEO is a 12 sq deg survey in NIR Z,Y,J,H, and K_s bands, specifically designed to enable the evolution of galaxies and large structures to be traced as a function of both epoch and environment from the present day out to z=4. and AGN and the most massive galaxies unto and into the epoch of reionization. Interplay between AGN, starbursts and environment, and role of feedback. Provide data over the VIDOE-XMM3 tile, which also covers CFHTLS-D1; addition of VIDEO data increases photometric redshift accuracy.
1206.4289
Low-mass tertiary companions to spectroscopic binaries I: common proper motion survey for wide companions using 2MASS
Allen, Burgasser, Faherty, Kirkpatrick
First results of a multi-epoch shear for wide (>few 10s AU), low-mass tertiary companions of 118 known spectra binaries within 30 pc of the sun using 2MASS point source catalog, and follow-up observations with KPNO and CTIO 4m telescopes. Sensitive to common proper motion companions with separations from 200 AU to 10k AU. 77 sources followed-up today, recover 11 previously known tertiaries, 3 previously known candidate tertiaries (2 spectroscopically confirmed and the other rejected) and 3 new candidates (2 confirmed, other rejected). Observed fraction consistent with predictions set out in SF simulations where the fraction of wide, low-mass companions to spectroscopic binaries is >10%, and is roughly twice the wide companion rate of single stars.
[Wed **/48] Jun 20
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