Day 381

Wednesday.

1303.0292
Recovering redshift distributions with cross-correlations: pushing the boundaries
Schmidt, Menard, Scranton, Morrison, McBride

Investigate impact of extending cross-correlaiton based redshift distribution recovery methods to include small scale clustering information.  The major concern in such work is the ability to disentangle the amplitude of the underlying redshift distribution from the influence of evolving galaxy bias.  use multiple sims covering a variety of galaxy bias evolution scenarios, and demonstrate reliable redshift recoveries using linear clustering assumptions well into the NL regime for redshift distributions of narrow redshift width.  Including information from intermediate physical scales balances the increased information available from clustering and the residual bias incurred from relaxing of linear constraints.  Discuss how breaking a broad sample into tomographic bins can improve estimates of the redshift distribution, and present a simple bias removal technique using clustering information from the spectroscopic sample alone.

1303.0304
Near-infrared spectroscopy of SN2009ip's 2012 brightening reveals a dusty pre-supernova environment
Smith (Nathan), .. Burgasser, et al

As the title says.

1303.3078
The solar corona: why it is interesting for us
Somov

Strong B-fields are of vital importance to the physics of the solar corona; they easily move a rarefied coronal plasma.  Physical origin of the main structural element of the corona, the so-called coronal streamers, is discussed.  It is shown that the reconnecting current layers inside streamers determine their large-scale structure and evolution, including creating, disruption and recovery.  Small-scale B-fields in the photosphere experience random motion.  Their reconnection appears to be an important source of energy flux for quiet-corona heating.  For active-corona heating, the peculiarities of entropy and magneto-acoustic waves, related to radiative cooling, are significant and should be taken into account in the coronal heating theory.

1303.0456
The efficiency and wavelength dependence of near-infrared interstellar polarization toward the galactic center
Hatano, et al

Polarization efficiency (PE) = ratio of degree of polarization to color excess; it is lower towards the Galactic center than in the Galactic disk by x3.  The spatial variation of PE vs. color excess, degree of polarization and position angle show: spatial variation of color excess and degree of polarization depend on Galactic latitude, while PE varies independently of galactic structure.  Position angls are nearly parallel to the Galactic plane, indicating the longitudinal B-field configuration between the Galactic center and us.  PE anticorrelates with dispersions of position angles.  The low PE and its spatial variation can be explained by the differences of the B-field directions along the LoS.  From the lower PE, suggest a hight strength of a random component relative to a uniform component of the B-field between the Galactic center and us.  The wavelength dependence of polarization are beta~2; exhibiting flattening toward longer wavelengths in the range of 1.25-2.14 um.  The flattening would be caused by aligned large-size dust grains.

1303.0538
An interacting galaxy system along a filament in a void
Beygu, et al

As the title says: VGS_31 is a small elongated group whose members are embedded in a common HI envelope.  The HI picture suggests a filamentary structure with accretion of intergalactic cold gas from the filament onto the galaxies.  Present deep optical and narrow band H_alpha data, spectroscopy, NUV and FUV Galex, and CO(1-0) data.  Find that one of the galaxies (Markarian object) has a ring-like structure and a tail evident both in optical and HI.  While all three galaxies form stars in their central parts, the tail and the ring of the Markarian object are devoid of SF.  Discuss these findings in terms of a gravitational interaction and ongoing growth of galaxies out of a filament.  System also shows that galaxy evolution in voids can be as dynamic as in high density environments.

1303.0554
Visible and near-infrared observations of asteroid 2012 DA14 during its closest approach of February 15th, 2013
de Leon, et al

The object can be classified as an L-type asteroid, not a very common spectral type among the asteroid population.  Has rotational period around 9 hours; the large amplitude of the variation suggests that the object is very elongated and irregular, with an equivalent diameter around 22m.  Geometric albedo is p_V = 0.34 pm 0.20.

1303.0580
A redshift dependent color-luminosity relation in type 1a supernovae
Mohlabeng, Ralston

Find a highly significant correlation of SNIa magnitudes in Union2.1 compilation of 580 sources.  Correlates magnitude residuals relative to LCDM model and (color x redshift) appears to be highly significant (13 sigma).  The goodness of fit chisq decreases by more than 50 units using one additional parameter linear in (color x redshift).  The new parameter shifts the SNe best-fit cosmological DE density parameter from Omega_L=0.71 to Omega_L=0.74, assuming a flat universe. The color-redshift correlation is quite robust, cannot be attributed to outliers, and passes several tests indicating it does not originate in data selection or systematic error assignments.  One physical interpretation is that SNe or their environments evolve significantly with increasing redshift.  The previously known rule that bluer SNe have larger absolute luminosity tends to flatten out observationally with increasing redshift.