Day 527

Friday.

1310.2301
WISE detections of known QSOs at redshifts great than six
Blain, .. Stern, .. Wright et al

WISE MIR survey detections of 17/31 QSOs at z>6 from SDSS, CFHTLS, FIRST, Spitzer and UKIDSS, increasing the quantity of IR data on these sources.  Particularly important for the Spitzer warm-mission phase with no faint follow-up capability for >5um until JWST.  Useful for understandings of QSOs found in forthcoming PanSTARRS, SkyMapper, VISTA, DES and LSST.  The rest-UV properties of WISE-detected and non-detected samples differ: the detections have brighter i/z-band magnitudes and redder rest-UV colors.  This suggests that a more aggressive hunt for very-high-z QSOs, by combining WISE W1 (3.4um) and W2 (4.6um) data with red observed optical colors could be effective at least for a subset of dusty candidate QSOs. Stacking the WISE images of the non-detected QSOs indicates that they are on average significantly fainted tha the WISE-detected examples, and are thus not narrowly missing detection in the WISE catalog.  The WISE-catalog detection of 3 of the sample in the W3 (12um) band indicates that their MIR flux can be detected individually, although there is no stacked W3 detection of sources detected in W1 but not W3.  (No QSO detection at W4=22um.)  Stacking analysis of WISE data for large AGN samples will be a useful tool, and high-z QSOs of all types will be easy targets for JWST.

1310.2314
First searches for optical counterparts to gravitational-wave candidate events
LIGO collaboration

No optical transient to GW candidate found.

1310.2372
Bias-hardened CMB lensing with polarization
Namikawa, Takahashi

Polarization data will provide the best avenue for CMB lensing potential, although it is potentially sensitive to instrumental effects, including beam asymmetry, polarization angle uncertainties, sky coverage, as well as analysis choices such as masking.  Derive "bias-hardened" lensing estimators to mitigate these effects, at the expense of somewhat larger reconstruction noise, and test them numerically on simulated data.  Find that the mean-field bias from masking is significant for the EE quadratic lensing estimator, however the bias-hardened estimator combined with filtering techniques can mitigate the mean field.  On the other hand, the EB estimator does not significantly suffer from the mean-field from masking.  The contamination from beam asymmetry and polarization angle uncertainties, however, can generate mean-field biases for the EB estimator.  These can also be mitigated using bias-hardened estimators, with at most a factor of ~2 degradation of noise level compared to the conventional approach.

1310.2400
HIFISTARS Herschel/HIFI observations of VY Canis Majoris.  Molecular-line inventory of the envelope around the largest known star
Alcolea et al

Detect J=6-5, 10-9, 16-15 lines of 12 CO and 13CO at 100, 300, and 750K above ground state; which are crucial for improving the modeling of the internal layers of the envelope around VY CMa.  Also detect 27 lines of H2O and its isotopomers, and 96 lines of species such as NH3, SiO, SO, SO2, HCN, OH and others, some originating from vibrationally excited levels.  Three lines were not unambiguously assigned.  Observations confirm that VY CMa's envelope must consist of 2 or more detached components.  The molecular excitation in the outer layers is significantly lower than in the inner ones, resulting in strong self-absorbed profiles in molecular lines that are optically thick in this outer envelope, for instance, low-lying lines of H2O.  Except for the most abundant species, CO and H2O, most of the molecular emission detected at these sub-mm/FIR wavelengths arise from the central parts of the envelope.  The spectrum of VY CMa is very prominent in vibrationally excited lines, which are caused by the strong IR pumping present in the central regions.  Compared with envelopes of other massive evolved stars, VY CMa's emission is particularly strong in these vibrationally excited lines, as well as in the emission from less abundant species such as H13CN, SO, and NH3.

1310.2419
Fast radio bursts may originate from nearby flaring stars
Loeb, Shvartzvald, Maoz

6 cases of FRBs discovered; bright (~0.1-1Jy) and brief (~1ms) pulses of radio emission with dispersion measures (DMs) that exceed Galactic values, interpreted to be at cosmological distances.  Instead, proposed that FRBs are rare eruptions of flaring MS stars within ~1kpc.  Rather than associating their excess DM with the intergalactic medium, relate it to a blanket of coronal plasma around their host stars.  Monitored at optical bands the stars within the radio beams of 3 of the known FRBs.  In one field, find a bright (V=13.6 mag) variable star (0.2 mag peak-to-trough) with a MS G-type spectrum and a period P=7.8 hr, likely a W-UMa-type contact binary.  Analysis of data outside of the FRB beams indicates a 5% chance probability of finding a variable star of this brightness and amplitude within the FRB beams.  Find no unusual variable stars in the other two FRB fields.  Further observations are needed to investigate if similar nearby (<~800 pc) stars are the sources of FRBs.

1310.2607
The SLUGGS survey: wide-field stellar kinematics of early-type galaxies
Arnold et al

...Observational results appear generally consistent with a picture of two-phase (in-situ plus accretion) galaxy formation.

1310.2672
Simulating the anisotropic clustering of luminous red galaxies with subhaloes: a direct confrontation with observation and cosmological implications
Nishimichi, Oka

Examine how well one can explain the large-scale anisotropic clustering of LRGs in SDSS with mock galaxies assigned to subhaloes identified in a large suite of high-res cosmological sims.  Vary the parameters that characterize the condition of subhaloes to host LRGs and search for the best-fit parameters to the observed multipole moments of the PS using the Markov-chain Monte Carlo method.  After demonstrating that we cannot find a reasonable fit to the observation when assigning mock LRGs only to the central population of subhaloes sitting at the center of their host haloes, show that simple models using both centrals and satellites can simultaneously fit the multipole moments up to hexadecapole at large scale (k~<0.3, h/Mpc).  The multiplicity function measured from the best-fit mock catalogs shows good agreement with the observation, when the mean spacial number density is adjusted by random sampling.  Finally demonstrate the possibility of simultaneous determination of the nature of LRGs and cosmological parameters by deforming the simulation box (the Alcock-Paczynski distortion) and changing by hand the velocities of mock LRGs (the amplitude of the redshift-space distortions).  Derive constraints on the Hubble parameter H(z), the angular diameter distance D_A(z), and the amplitude of the velocity perturbations f sigma_8(z) by utilizing a clear acoustic feature in the observed spectrum.  Argue the robustness of these constraints against the range of the wavenumber used in the fit, and conclude that the cosmological model assumed in the simulations as well as in the redshift-distance conversion has a significant discrepancy with the true one.