Day 549

Wednesday.

1311.3783
The dynamical fingerprint of core scouring in massive elliptical galaxies
Thomas, .. Bender, .. et al

The most massive elliptical galaxies have low density centers or cores that differ dramatically from the high-density centers of less massive ellipticals and bulges of disk galaxies.  These cores have been interpreted as the result of mergers of SMBH binaries, which depopulate galaxy centers by gravitationally slingshotting central stars towards large radii.  Sucn binaries naturally form in mergers of luminous galaxies.  Analyse the population of central stellar orbits in 11 massive elliptical galaxies observed with SINFONI at ESO-VLT.  Dynamical analysis is orbit-based and includes the effects of a central black hole, the mass distribution of the stars and DM halo.  Show that the use of integral field kinematics and the inclusion of the DM is important to conclude upon the distribution of stellar orbits in galaxy centers.  Six of the galaxies are core galaxies.  In these six galaxies, but not in the galaxies without cores, detect a coherent lack of stars on radial orbits in the core regions and a uniform excess of radial orbits outside of it: when scaled by the core radius, the radial profiles of the classical anisotropy parameter beta are nearly identical in core galaxies.  Moreover, they match quantitatively the predictions of BH binary simulations, providing the first convincing dynamical evidence for core scouring in the most massive elliptical galaxies.

1311.3926
Weak lensing using only galaxy position angles
Whittaker, Brown, Battye

Develop a method for WL analysis using only measurements of galaxy position angles [of the ellipticity??].  Analyze the statistical properties of the galaxy orientations given a known intrinsic ellipticity distribution, show that it is possible to obtain estimate of the shear by minimizing a chi sq statistic.  The method is demonstrated using simulations where the components of the intrinsic ellipticity are taken to be Gaussian distributed.  Uncertainties on the position angle measurements introduce a bias into the shear estimates which can be reduced to negligible levels by introducing a correction term into the formalism. Generalize approach by developing an algorithm to obtain direct shear estimators given any azimuthally symmetric intrinsic ellipticity distribution.  Demonstrate this technique by applying it to simulations where the ellipticities are taken to follow a log-normal distribution.  Compare the performance of the position angle only method with the standard method based on full ellipticity measurements by reconstructing lensing convergence maps from both numerical simulations and from the CFHTLenS data.  Find that the position angle only method exhibits a performance comparable with that of the standard estimator and has the potential to reduce errors on the shear estimates as compared with the standard method in the case where the intrinsic ellipticity distribution is accurately known.

1311.4169
TAPAS, a web-based service of atmospheric transmission computation for astronomy
Bertaux, et al

Transmissions of the AtmosPhere for AStronomical data (TAPAS): first purpose is to allow identification of observed spectral fixtures as being from atmospheric or astrophysical origin.  Computes the atmospheric transmission in the LoS to the target indicated by the user.  Actual atmospheric profile (temperature, pressure, humidity, ozone content) is entered, and transmission computed for a number of gases: O2, H2O, O3, CO2, and Rayleigh extinction.  The TOA (Top Of Atmosphere) spectrum may be obtained either by division of the observed spectrum by the computed transmission or other techniques developed on purpose.    Wavelength range is 500-2500nm.  Show some results for O2 and H2O atmospheric absorption.

1311.4259
Nature of H-alpha selected galaxies at z>2.1 I. Main sequence and dusty star-forming galaxies
Tadaki et al

Results from the narrow-band imaging surveys of HAEs at z=2.2 and 2.5 with NIR MORICS on Subaru.  Clean sample of 63 SF galaxies at z=2.2 and 46 at z=2.5.  For 12/13 HAEs (H-alpha emitters) at z=2.2, Ha lines successfully detected by spectra.  42% of red, massive HAEs with M*>1e1.8 Msun contain AGNs, most of the blue, less massive ones are likely to be SF galaxies.  This suggests that the AGN may play an important role in galaxy evolution at the late stage of truncation.  FOr the HAEs excluding possible GNs, estimate the gas-phase metallicities on the basis of N/Ha ratios, and find that the metallicities of the Ha selected galaxies at z=2.2 are lower than those of local SF galaxies at fixed stellar mass (consistent with previous results).  Moreover, present and discuss the so-called MS of SF galaxies at z>2 based on the sample of HAEs.  Bye correlating the level of dust extinction with the location f the MS, find that there are two kinds/modes of dusty SF galaxies: star-bursting galaxies and metal-rich normal SF galaxies.

1311.4484
Weak lensing with 21cm intensity mapping at $z \sim 2-3$
Pourtsidou, Metcalf

How 21 cm intensity mapping can be used to measure gravitational lensing over a wide range of redshift.  Can extend WL measurements to higher redshifts than are accessible with conventional galaxy surveys.  Construct a convergence estimator taking into account the discreteness of galaxies and calculate the expected noise level as a function of redshfit and telescope parameters.  At z~2-3, find that a telescope array with a clooecting area ~0.2 km&2 spread over a region with diameter ~2 km would be sufficient to measure the convergence PS to high accuracy for multiples between 10 and 1000.  Show that these measurements can be used to construing interacting DE models.

1311.4544
An environmental study of the Ultraluminous X-ray source population in early-type galaxies
Plotkin, .. Treu, et al

Ultra-luminous X-ray sources (ULXs) are one of the brightest phenomena found outside of a galaxy's nucleus, and their explanation typically invokes accretion of material onto a BH.  Largest population study to date in early-type galaxies; study whether a galaxy's large scale environment can affect its ULX content.  Constrain the number of ULXs per unit stellar mass (ULX specific frequency) is 0.06pm0.01 ULXs per 1e10 Msun (about 1 ULX per 1.6e11 Msun of galaxy stellar mass).  Find that the number of ULXs, the specific frequency of ULXs, and the average ULX spectral properties are all similar in both cluster and field environments.  Contrary to late-type galaxies, do not see any trend between specific ULX frequency and host galaxy stellar mass, and show that dwarf ellipticals host fewer ULXs than later-type dwarf galaxies at a statistically meaningful level.  Results are consistent with ULXs in early-type galaxies probing the luminous tail of the low-mass X-ray binary population, and are briefly discussed in context of the influence of gravitational interactions on the long-term evolution of a galaxy's (older) stellar population.

1311.4549
Chemodynamics of the Milky Way.  I.  The first year of APOGEE data
Anders et al

Choose 20,000 stars with high-quality chemistry sample; compute distances and orbital parameters for this sample, employ a number of useful subsets to formulate constraints on Galactic chemical and chemodynamical evolution processes in the Solar neighborhood and beyond (Metallicity distributions (MDFs), [alpha/Fe] vs [Fe/H] diagrams, and abundance gradients).  Red giant sample spans distances as large as 10 kpc from the Sun, increasing by at least a factor of eight the studied volume wrt the most recent chemodynamical studies.  Find remarkable agreement between the recently published local (d<100pc) high-res high-S/N HARPS sample and the local HQ sample (d<1 kpc).  The local MDF peaks slightly below solar metallicity, and exhibits and extended tail towards [Fe/H]=-1, whereas a sharper cutoff is seen at larger metallicities.  THe APOGEE data also confirm the existence of a gap in the abundance diagram.  When expanding sample to cover three different Galactocentric distance bins, find the high-[alpha/Fe] stars to be rare towards the outer zones, as previously suggested in the literature.  For the gradients in [Fe/H] and [alpha/Fe], measured over a range of 6<R<11 kpc in Galactocentric distance, find a good agreement with the gradients traced by the GCS and RAVE dwarf samples.  For stars with 1.5<z<3 kpc, find a positive metallicity gradient and a negative gradient in [alpha/Fe].

1311.4562
Large scale alignments from WMAP and Planck
Copi et al

Compare data sets, the quadruple and octupole and their joint alightment with the CMB dipole direction and the geometry of SS --- they're all still there, through WMAP and Planck don't quite agree.

1311.4574
The 21-cm signal from the cosmological epoch of recombination
Fialkov, Loeb

H recombination at z~500-1100 correspond to wavelengths of 100-230 meters.  THe 21-cm line deviates from thermal equilibrium with the CMB due to the excess Lya radiation from H and He recombinations.  The resulting 21-cm signal reaches a brightness temperature of a milli-Kelvin, orders of magnitude larger than previously estimated.  Its detection by a future lumbar or space-based observatory could improve the statistical constraints on the cosmological initial conditions compared to existing 2-dimensional maps of the CMB anisotropies.

1311.4576
Metallicity evolution, metallicity gradients and gas fractions at z~3.4
Troncoso et al

NIR IFS observations for 40 SF galaxies at 3<z<5 (mostly at z~3.4) measure metallicities by strong emission line.  Find: significant fraction of SF galaxies at z~3.4 deviate from the fundamental metallicity relation (FMR), by having a metallicity up to a factor of 10 lower than expected by the FMR.  The deviation does not correlate with the dynamical properties of the galaxy or with the presence of interactions.  To further investigate the origin of the metallicity deviations, also infer information on the gas content, by inverting the Schmidt-Kennicutt relation.  In agreement with recent CO observational data, find that in contrast with the steeply rising trend at 0<z<2, the gas fraction in massive galaxies remains constant, with indication of a marginal decline, at 2<z<3.5.  When combined with the metallicity information, infer that, in order to explain both the low metallicity and gas content in z~3.4 galaxies, both prominent outflows and massive pristine gas inflows are needed.  In ten galaxies, can also spatially resolve the metallicity distribution.  Find that generally the metallicity anti correlates with the distribution of SF and with the gas surface density.  Discuss these findings, both in terms of pristine gas inflows towards the center and outflows of metal rich gas from the center towards the external regions.

1311.4608
Jumping the energetics queue: modulation of pulsar signals by extraterrestrial civilizations
Chennamangalam et al

Discuss the possibility of a civilization using naturally occurring radio transmitters (radio pulsars) to overcome the Kardashcev limit of their developmental stage and transmit super-Kardashev power.  This is achieved by the use of a modulator situated around a pulsar, that modulates the pulsar signal, encoding information onto its natural emission  Discuss a simple modulation mode using pulse nulling and considerations for detecting such a signal.  Find that a pulsar with a nulling modulator will exhibit an excess of thermal emission peaking in the UV during its null phases, revealing the existence of a modulator.

1311.4870
The Sloan digital sky survey quasar catalog: tenth data release
Paris et al

DR10Q from BOSS, first 2.5 years of survey, confirmed quasars via visual inspection of the spectra.  The catalog also includes known quasars from earlier SDSS data also observed by BOSS.  Contains 166k quasars (74k are new discoveries since DR9) detected over 6373 sq deg with robust identification and redshift measured by a combination of principal component eigenspectra.  Number of quasars with z>2.15 is ~5x greater than the number of z>2.15 quasars known prior to BOSS.  Z and FWHMs are provided from the strongest emission lines (CIV, CIII, MgII).  the catalog identifies 16k broad absorption line quasars and gives their characteristics.  For each object, the catalog presents 5-band photometry with 0.03mag accuracy and information on the optical morphology and selection method.  Also contains X-ray, UV, NIR and radio emission properties of the quasars, when available, from other large-area surveys.  The calibrated digital spectra cover the wavelength region 3600-10,500A at a spectra resolution in the range 1300<R<2500; the spectra can be retrieved from the SDSS Catalog Archive Server.  Also provide a supplemental list of an additional 2376 quasars that have been identified among the galaxy targets of the SDSS-III/ BOSS.