Bulletin of the American Physical Society
APS April Meeting 2012
Volume 57, Number 3
Saturday–Tuesday, March 31–April 3 2012; Atlanta, Georgia
Session X3: Invited Session: Hot Topics in Astrophysics |
Hide Abstracts |
Sponsoring Units: DAP DCOMP Chair: Neil Cornish, Montana State University Room: Hanover CDE |
Tuesday, April 3, 2012 1:30PM - 2:06PM |
X3.00001: First BAO Results from the Baryon Oscillation Spectroscopic Survey Invited Speaker: Nikhil Padmanabhan We present the first baryon acoustic oscillation (BAO) results from the Baryon Oscillation Spectroscopic Survey (BOSS) galaxy sample. We analyze spectroscopic data from the first two years of the survey with 325,000 galaxies over 3800 sq.deg. and between redshifts of 0.45 and 0.7. The galaxy clustering results show unambiguous evidence for a BAO signal. We present our distance measurement to z=0.6, and discuss its implications for measurements of the properties of dark energy. [Preview Abstract] |
Tuesday, April 3, 2012 2:06PM - 2:42PM |
X3.00002: Neutrinos in Cosmology Invited Speaker: Lloyd Knox A number of lines of evidence (both laboratory and astrophysical) suggest that there are extra (sterile) neutrino species, or otherwise extra light degrees of freedom than exist in the standard model of particle physics. In this talk I will review the astrophysical evidence for these extra degrees of freedom, as well as constraints on neutrino masses. Relevant data come from emission spectra of extragalactic regions of ionized gas (used to infer the primordial Helium abundance), high-resolution observations of the cosmic microwave background as well as measurements of the large-scale structure in the low-redshift Universe. The astrophysical evidence for extra light degrees of freedom is currently not highly compelling. We can expect a much clearer picture to come from Planck data in 2013. [Preview Abstract] |
Tuesday, April 3, 2012 2:42PM - 3:18PM |
X3.00003: The Puzzling Darkness of Massive Milky Way Subhalos Invited Speaker: Michael Boylan-Kolchin A firm prediction of the cold dark matter model of cosmological structure formation is that the Milky Way should host a huge population of self-bound dark matter subhalos. The vast majority of these subhalos are likely devoid of stars, but a tiny minority are expected to host the luminous dwarf galaxies observed around the Milky Way. These are the most dark matter-dominated galaxies presently known, and are therefore excellent laboratories for testing theories about galaxy formation and the properties of dark matter. I will discuss a new comparison of the structure and abundance of Milky Way satellite galaxies with predictions based on cold dark matter simulations, which has revealed a perplexing tension: massive dark matter subhalos, the putative hosts of luminous satellites, are much more dense than the observed dwarf galaxies orbiting the Milky Way. I will also review plausible explanations of this serious discrepancy, which include the possibility that galaxy formation is markedly different in low-mass dark matter halos than in larger systems, that baryonic processes wreak havoc on dark matter subhalos, or that the nature of dark matter differs from the canonical picture of a massive, weakly interacting particle. [Preview Abstract] |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700