Day 706

Wednesday.

1407.5619
The starfish diagram: visualizing data within the context of survey samples
Konstantopoulos

A novel but simple plot that simultaneously visualizes the properties of the sample and the individual: a 'starfish diagram'.  The utility and versatility of the plot is demonstrated through its application to astrophysical data and sports statistics.  Provide a brief description of the concept and the source code.

1407.5622
Constraints on core collapse from the black hole mass function
Kochanek

Model the observed BH MF under the assumption that BH formation is controlled by the compactness of the stellar core at the time of collapse.  Low compactness stars are more likely to explode as supernovae and produce neutron stars, while high compactness stars are more likely to be failed SNe that produce BHs with the mass of the He core of the star.  From 3 stellar model sequences and marginalizing over a model of completeness of the BH MF, find that the compactness xi(2.5) above which 50% of core collapses produce BHs is xi(2.5)=0.24 (0.15<xi(2.5)<0.37 at 90% confidence).  While models with a sharp transition between successful and failed explosions are always the most likely, the width of the transition between the minimum compactness for BH formation and the compactness above which all core collapses produce BHs is not well constrained.  The models also predict that f=0.18 (0.09<f<0.39) of core collapses fail assuming a minimum mass for core collapse of 8Msun.  Tested 4 other criteria for BH formation based on xi(2.0) and xi(3.0), the compactnesses at enclosed masses of 2.0 or 3.0 rather than 2.5 Msun, the mass of the Fe core, and the mass inside the O burning shell.  Find that xi(2.0) works as well as xi(2.5), while the compactness xi(3.0) works significantly worse, as does using the Fe core mass or the mass enclosed by the O burning shell.  As expected from the high compactness of 20-25 Msun stars, BH formation in this mass range provides a natural explanation of the red supergiant problem [what is the RSG problem?].

1407.5623
Mapping the integrated Sachs-Wolfe effect
Manzotti, Dodelson

Present a likelihood technique for extracting the ISW signal from measurements of CMB, galaxy distribution, and maps of gravitational lensing.  

1407.5627
Surface photometry of BCGs and intracluster stars in Lambda-CDM
Cooper, Gao, Guo, Frenk, Jenkins, Springel, White

SB profiles of BCGs (from simulations) match well to observations.  On average, stars formed in galaxies accreted by the BCG account of ~90% of its total mass, remainder formed in situ.  In circular BCG-centered apertures, the superposition of multiple debris clouds (each ~10% of the total BCG mass) from different progenitors can result in an extensive outer diffuse component, qualitatively similar to a 'cD envelope'.  These clouds typically originate from tidal stripping at z<1 and comprise both streams and the extended envelopes of other massive galaxies in the cluster.  The faint regions of the BCG contribute a significant part of the total cluster stellar mass budget: in the central 1Mpc^2 of a z~0.15 cluster imaged at SDSS-like resolution, the fiducial model predicts 80-95% of M* below a SB of mu_V=26.5 mag arcsec^-2 is associated with accreted stars in the envelope of the BCG.  The ratio of BCG stellar mass to total cluster stellar mass is ~30%.

1407.5686
The distortion of the cosmic microwave background by the Milky Way
Czaja, Bromley

MW acting as a large-scale weak gravitational lens of the CMB.  Study this effect using a photon ray-tracing code and galactic mass distribution with disk, bulge and halo components.  For an observer at the Sun's coordinates in the Galaxy, the bending of CMB photon paths is limited to less than 1 arc second, and only for rays that pass within a few degrees of the Galactic Center.  However, the entire sky is affected, resulting in global distortions of the CMB on large angular scales.  These distortions can cause the low-order multipoles of a spherical harmonic expansion of the CMB sky temperature to leak into higher-order modes.  Thus the component of the CMB dipole that results from the Local Group's motion relative to the local cosmic frame of rest contributes to higher-order moments for an observer in the solar system. With the ray-tracing code, show that the phenomenon is not sensitive to the specific choice of Galactic potential.  Also quantitatively rule it out as a contributor to CMB anomalies such as power asymmetry or correlated alignment of low-order multipole moments.

1407.5928
BICEP3: a 95 GHz refracting telescope for degree-scale CMB polarization
Ahmed et al

BICEP3 is a 550mm-aperture refracting telescope for polarimetry of radiation in the CMB at 95 GHz.  Similar to BICEP1 and 2, it possesses sufficient resolution to search for signatures of the inflation-induced cosmic gravitational-wave background while utilizing a compact design for ease of construction and to facilitate the characterization and mitigation of systematics.  However, BICEP3 represents a significant breakthrough in per-reciever sensitivity, with a focal plane area 5x larger than a BICEP2/Keck array receiver and faster optics.  Large-aperture IR-reflective metal-mesh filters and IR-absorptive cold alumina filters and lenses were developed and implemented for its optics.  The camera consists of 1280 dual-polarization pixels; each is a pair of orthogonal antenna arrays coupled to transition-edge sensor bolometers and read out by multiplexed SQUIDs.  Upon deployment at the SP during the 2014-15 season, BICEP3 will have survey speed comparable to Keck Array 150 GHz (2013), and will significantly enhance spectral separation of primordial B-mode power from that of possible galactic dust contamination in the BICEP2 observation patch.