Day 309

Tuesday.  69 abstracts today!

1210.0004
Dipole leakage and low CMB multipoles
Das, Souradeep

WMAP7 show low power in low multipoles than predicted, with angular correlation in their orientation.  CMB dipole is 550x larger than quadrupole, and can leak into higher multipoles because of the non-circular beam of WMAP.  Simulation for Planck scan strategy, and comparison with WMAP presented.

1210.0009
Evolution of Quiescent and star-forming galaxies since z~1.5 as a function of their velocity dispersions
Bezanson, van Dokkum, Franx

Measure M* and structural parameters for 5.5k quiescent and 20k SF galaxies at 0.3<z<1.5 in COSMOS and UKIDSS fields.  Combine to infer velocity dispersions and determine how the number density of galaxies at fixed inferred dispersion (velocity dispersion function, VDF) evolves with time for each population.  Show: number of galaxies with high velocity dispersions surprisingly stable with time, regardless of their SFH.  The overall VDF for SF galaxies is constant with z, extending down to the lowest velocity dispersions probed by this study.  The only galaxy population showing strong evolution are quiesceent galaxies with low inferred dispersions, whose number density increases by 4x since z=1.5.  This build-up leads to an evolution in the quiescent fraction of galaxies such that the threshold dispersion above which quiescent galaxies dominate the counts moves to lower velocity dispersion with time.  Show: results are consistent with a simple model in which SF galaxies quench and are added to the quiescent population.  In order to compensate for the migration into the quiescent population, the velocity dispersions of SF galaxies must increase, with a rate that increases with dispersion.

1210.0014
The dynamics of merging clusters: a monte carlo solution applied to the bullet and musket ball clusters
Dawson

Address weakness in constraining DM cross-section, the understanding of the dynamics of the cluster merger: X-section is a function of both velocity of the collision and the observed time since collision.  Both N-body and simple analytic models exist, but unfeasible to address this issue.  Develop a MC method to discern the merger dynamics of systems and propagate the uncertainty of the measured cluster parameters in an Bayesian manner.  Verify against numerical simulations, apply to two observed clusters.  Better than existing analytic models, agree within 10% of N-body simulations.  [what is the scientific significance??]

1210.0020
Late time radio emission from X-ray selected tidal disruption events
Bower, Metzger, Cenko, Silverman, Bloom

VLA observations of X-ray selected TDEs, 9 to 22 years after the initial x-ray discovery; probe the late-time formation of relativistic jets and jet interactions with the interstellar medium.  2 compact radio sources found, but none for the 5 others.  >~10 % of TDEs are accompanied by relativistic jets.  Need more observations to constrain the nature of the jets in these systems.

1210.0032
CFHTLenS: the Canada-France-Hawaii telescope lensing survey
Heymans, Van Waerbeke, Miller, ERben, Hildebrandt, Hoekstra, Kitching, Mellier, Simon, ... Kilbinger, Kuijken, Rowe, Schrabback, Sembolini, van Uitert, et al

154 sq. deg. WL survey, powerful but technically challenging.  Outline the analysis pipeline, all steps improved.  New method to identify data which contributes a non-negligible contamination to the sample and quantify the required level of calibration for the survey.  Cosmology-insensitive tests demonstrate the robustness of the resulting cosmic shear signal, present a science-ready shear and photo-z catalogue.

1210.0040
An argument that the dark matter is axions
Sikivie

Axions (1) behave differently than other CDM, since it forms a rethermalizing [?] Bose-Einstein condensate.  (2) Observations of inner caustics of galactic haloes makes them distinguishable.  (3) Observational evidence of caustic rings of DM is consistent with axion BEC.

1210.0045
Globular cluster systems of early-type galaxies - do we understand them?
Richtler

GCs in early-type galaxies: cluster formation to galaxy formation and evolution, observational techniques.  Cluster systems of central galaxies may owe their richness to a plethora of less spectra galaxies and their SF processes; dwarf galaxies occupy a particularly important role.

1210.0073
Updated analysis of a "dark" galaxy and its blue companion in the Virgo cloud HI 1225+01
Matsuoka, Ienaka, Oyabu, Wada, Takino

An intergalactic gas cloud located on the outskirts of Virgo cluster: two large clumps of comparable HI masses (1e9Msun) separated by 100 kpc.  One of the clumps hosts a blue low-surface-brightness galaxy, while the other has no identified stellar emission, a "dark galaxy" (optically invisible massive intergalactic system).  Present a deep optical image covering the whole structure, with archival data from UV to FIR from the knot in the LSB galaxy ("R1").    R1 has stellar population of 10-100 Myr and 1e6 Msun, NIR excess brightness implying presence of hot dust with temperature 600 K, and faint MIR and FIR corresponding to dust mass up to 100 Msun.  Shares geleral properties with low-metallicity blue compact dwarf galaxies.  No optical counterpart to the other clump, down to R_AB>28 mag/arcsec^2---100x fainter than the brightest part of the companion galaxy.

1210.0197
Reionization and the cosmic dawn with the square kilometre array
Mellema, et al

What SKA can do.   [white paper, no details given in abstract]

1210.0242
Star formation in quasar host galaxies at redshift 6: millimeter surveys and new insights from ALMA
Wang, .. Fan, Bertoldi, ... Strauss, et al

14 z~6 quasars observed, birght in millimeter dust continuum with FIR luminosities 1e12 to 1e13 Lsun; also detected in molecular CO line emission, indicating molecular gas masses of 1e10 Msun.  CII fine structure line emission also detected in all.  Suggest: massive SF at rates of about 600 to 2000 Msun/yr over the central few kpc region of these quasar host galaxies.

1210.0285
SEDFit: software for spectral energy distribution fitting of photometric data
Sawicki

As the title says.  Discussion of issues and caveats applicable to SED-fitting in general.

1210.0302
An x-ray detected group of quiescent early-type galaxies at z=1.6 in the chandra deep field south
Tanaka, Finoguenov, et al

As the title says. High fraction of AGN (40%), but no statistical sample available for comparative study for AGN quenching.

1210.0313
Re-calibration of SDF/SXDS photometric catalogs of Suprime-Cam with SDSS Data release 8
Yagi, Suzuki, ... et al

Significant zero-point offsets in i and z band (~0.1 mag) in Subaru deep field wrt SDSS DR8; 0.1 mag offset in B between SDF and SXDS catalogs.  Origin of discrepancy not understood.

1210.0334
THe cosmic evolution of oxygen and nytrogen abundances in star-forming galaxies over the last 10 Gyrs
Perez-Montero, et al

20k bright sample of zCOSMOS, use N/O ratio as SFR independent tracer of gas phase chemical evolution of galaxies.  Use emission-line galaxies in SDSS and zCOSMOS to study the evolution from the local universe of MZR (mass-metallicity relation) up to z~1.32, and M* to N/O ratio (MNOR) up to z~0.42.  Confirm trend to find lower metallicities in galaxies of a given stellar mass in a younger universe [makes sense], even when selection effects such as larger observed median SFR at high z.  Find significant evolution of MNOR up to z=0.4; consistent with the trends found for both MZR and its equivalent relation using new expressions to reduce its dependence on SFR.

1210.0338
Star formation history of resolved galaxies.  I.  The method
Small, Bersier, Salaris

A new method to determine the SFH and metal enrichment histories of any resolved stellar system.  Based on the fact that any observed star in a color-mag diagram will have a certain probability of being associated with an isochrone characterized by age t and metallicity [Fe/H].  Test on GC and open clusters.  Works well with Carina and its history.

1210.0422
The relation between nuclear activity and stellar mass in galaxies
La Mura, et al

Correlation between nuclear properties (M_BH, M_bulge, L_bulge) represent a fundamental constraint on galaxy evolution.  No reason identified yet; could stem from a connection between the processes that lead to BH growth and stellar mass assembly ("Starburst-AGN connection").  Analyze large sample of galaxies, study relation between properties of nuclear environments and their host galaxies.  Find: mass of the stellar component within the galaxies is a critical parameter, must consider an evolutionary sequence.  [seems incomplete.]

1210.0439
Observables and unobservables in dark energy cosmologies
Amendola, et al

FInd: goal of reconstructing DE models fundamentally limited by the unobservability of the present values of Omega_m0, sigma_8 and present matter power spectrum.  On the other hand, under certain conditions, cosmological observations can still ruleout entire class of the most general single scalar-field models.