Sunday. Lunch at Peter Schneider's. Exotic fruits, roasted duck. Now I'm not sure if I can work (sleepy).
1109.6326
A multi-wavelength study of the radio source G296.7-0.9: confirmation as a Galactic supernova remnant
Robbins, Gaensler, Murphy, Reeves, Green
* as the title says.
1109.6328
Measures of galaxy environment I -- what is "environment"?
Muldrew, ... Skibba, ... Park, ... et al
Differing techniques often used to define environment: either (i) use nearest neighbors to probe the underlying density field, or (ii) used fixed apertures. The differences between the two inhibit a clean comparison between analysis and leave open the possibility that, even with the same data, different properties are actually being measured. Compare 20 different published methods to define environment, find that the nearest neighbour-based measures best probe the internal densities of high-mass haloes, while at low masses the inter-halo separation dominates and acts to smooth out local density variations. Nearest neighbor galaxy environment is largely independent of dark matter halo mass. Conversely, aperture-based methods that probe super-halo scales accurately identify high-density regions corresponding to high mass haloes. Both methods show how galaxies in dense environments tend to be redder, with the exception of largest apertures. Largest apertures are the strongest at recovering the BG DM environment. Warn against using photometric redshifts to define environment in all but the densest regions. When considering environment there are two regions: the 'local environment' internal to a halo best measured with nearest neighbour and 'large-scale environment' external to a halo best measured with apertures. Conclude: there is no universal environment measure and the most suitable methods depends on the scale being probed.
* for small scale, use nearest neighbor. for large scale, use aperture.
1109.6333
Cosmological information in weak lensing peaks
Yang, Kratochvil, Wang, Lim, Haiman, May
Convergence peaks N(kappa) in WL maps can be a useful probe of cosmology. Study (i) physical origin of WL peaks with different heights, and (ii) whether the peaks contain information beyond the convergence power spectrum P_ell. Find: high peaks with >3.5 sigma are typically dominated by a single massive halo; medium peaks (>0.5-1.5 sigma) cannot be attributed to a single collapsed DM halo, and are instead created by the projection of a multiple (typically, 4-8) haloes along the LOS, and by random galaxy shape noise. Nevertheless, these peaks dominate the sensitivity of the cosmological parameters w, sigma_8 and Omega_m. Find: peak height distribution and its dependence on cosmology differ significantly from predictions in a Gaussian random field. Directly compute the marginalized errors on w, sigma_8 and Omega_m from N(kappa) + P_ell combination, including redshift tomography with soruce galaxies at z_s=1 and z_s=2. Find: N(kappa) and P_ell combination has approximately twice the cosmological sensitivity compared to P_ell alone. These results demonstrate the N(kappa) contains non-Gaussian information complementary to the power spectrum.
* non-Gaussian information that is sensitive to the total matter, too.
1109.6334
Probing cosmology with WL Minkowski functionals
Kratochvil, Lim, Wang, Haiman, May, Huffenberger
* Minkowski functionals: In functional analysis, given a linear space X, a Minkowski functional is a device that uses the linear structure to introduce a topology on X.
* how does one calculate these functionals? I guess there is "area", "length" and "genus", from below...
Study the cosmological information content of MFs derived from mock WL convergence maps. Esstimate the joint confidence contours of the 3 parameters w, sigma_8 and Omega_m. Use redshift tomography at 3 different source redshifts z=1, 1.5, 2 and 5 different smoothing scales 1,2,3,5,10 arcmin; explicitly compare and combine the MFs wit the WL power spectrum. Find MFs capture a substantial amount of information from non-Gaussian features of convergence maps beyond the power spectrum. The MFs are well suited to break degeneracies and constrain w by a factor of ~3 than power specturm alone. The non-Gaussian information derives partly from the one-point function of the convergence (V_0, the "area" MF), and partly through non-linear spatial information (through combining different smoothing scales for V_0 and through V_1 and V_2, the boundary length and genus MFs, respectively). In contrast to the power spectrum, the best constraints from the MFs are obtained only when multiple smoothing scales are combined.
1109.6349
Cataclysmic variables from SDSS. VIII. The final year (2007-2008)
Szkody, Anderson, ... Ross, ... Knapp, ... et al
Cataclysmic variables (CVs) identified from SDSS I/II completed. Coordinates, magnitudes and spectra of 33 CVs are presented. 8 previously known to SDSS; 9 objects recently found through various photometric surveys. Two polar candidates, two intermediate polar candidates, and one candidate for containing a pulsating white dwarf. Followup data confirmed a polar candidate from Paper VII and determined tentative periods for three of the enewly identified CVs. A complete summary table of the 285 CVs with spectra from SDSS I/II is presented as well as link to an online table of all known CVs from both photometry and spectroscopy that will continue to be updated as future data appear.
1109.6400
NEOWISE observations of near-earth objects: Preliminary results
Mainzer, et al
Near-earth objects (NEO) Wide-field infrared survey explorer (WISE) from 3 to 22 microns. Discovery of >130 new NEOs. Exporation of 428 near-Earth asteroids (NEA's) detected by NEOWISE during the fully cryogenic portion of the WISE mission. There are 981 NEAs larger than 1km and 20k\pm3k larger than 100m. Spaceguard goal of detecting 90% of all 1km NEAs has been met; cumulative size distribution is best represented by a broken power low with a slope of 1.32 below 1.5 km. The power law slope produces 13k pm 2k NEAs with D>140m.
1109.6571
Gravitational redshift of galaxies in clusters as predicted by general relativity
Wojtak, Hansen, Hjorth
Test of GR within LCDM concordance between predictions and the observations of the growth rate and clustering of the comic web. GR has not been tested on cosmological scales independent of the assumptions of the LCDM model. Report observations of the gravitational redshift of light coming from galaxies in clusters at the 99 per cent confidence level, based on archival data. Measurement agrees with the predictions of general relativity and its modification created to explain cosmic acceleration without the need for DE (f(R) theory), bus is inconsistent with alternative models such as MOND.
* related question: what is the Reyes paper?
1109.6493
Star formation near and obscured AGN: Variations in the initial mass function
Hocuk, Spaans
Conditions that affect the formation of stars in radiatively and mechanically active environments: a variety of feedback processes can play a significan role in shaping the IMF. Present numerical study of SM around an accreting 800 M_sun BH in a molecular cloud at 10pc from the BH. Parameterize and study radiative feedback effects of hard X-rays emanating from the BH broad line regions, increased CR rates due to SNe in starbursts, and strong UV radiation produced by nearby massive stars. We also investigate the importance of shear from the SMBH as the star-forming cloud orbits around it. Find thermal pressure from X-rays compresses the cloud, which induces a high star formation rate early on, but reduces the overall star formation efficiency to about 7% due to gas depletion by evaporation. The turn-over mass of the IMF increases up to a factor of 2, M_turn=1-1.5 M_sun, for the model with the highest X-ray flux, while the high-mass slope of the IMF becomes Gamma>-1. This results in more high mass stars and a non-Salpeter initial mass function. Cosmic rays penetrate deeply into the cloud and increase the gas temperature (50-200K), which leads to a reduced formation efficiency of low mass stars. High CR rates increase the average mass of stars, thereby shifting the turn-over mass to higher values (up to several solar masses). Due to this process, the onset of star formation is also delayed. Conclude initial mass function inside active galaxies is different that the one obtained from local environments.
* thermal pressure from X-ray compresses the molecular cloud?
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