Bulletin of the American Physical Society
2008 Joint Fall Meeting of the Texas and Four Corners Sections of APS, AAPT, and Zones 13 and 16 of SPS, and the Societies of Hispanic & Black Physicists
Volume 53, Number 11
Friday–Saturday, October 17–18, 2008; El Paso, Texas
Session J1: Astrophysics and Astronomy II |
Hide Abstracts |
Chair: Stacy Palen, Weber State University Room: Union East, 3rd Floor University |
Saturday, October 18, 2008 1:30PM - 1:54PM |
J1.00001: Opportunities for Astronomical Research using the U.S. System of Ground-Based Optical and Infrared Telescopes Invited Speaker: The National Optical Astronomy Observatory (NOAO) manages access to a variety of ground-based telescopes, spanning a range in aperture size, which offer observational capabilities reaching from the near-ultraviolet, through the visual, and into the infrared spectral regions. NOAO's mission is to provide these ground-based astronomical facilities to the nation's astronomers, to promote public understanding and support of science, and to help advance all aspects of US astronomy. As a national facility, NOAO telescopes are open to all astronomers and their students, free of charge, regardless of institutional affiliation, through a peer-reviewed proposal process. NOAO is funded by the National Science Foundation and operated by the Association of Universities for Research in Astronomy, Inc. NOAO has its headquarters in Tucson, Arizona. The overall observational capabilities provided by NOAO will be reviewed, along with recent science highlights, and an outline of future plans for the next decade. [Preview Abstract] |
Saturday, October 18, 2008 1:54PM - 2:18PM |
J1.00002: Latest results from the Pierre Auger Observatory Invited Speaker: Since the first detection of a cosmic ray with energy above $10^{20}$~eV in 1962, their nature and origin remain unknown. At these energies, it is expected that the cosmic ray flux undergo a strong suppression. Due to the extreme rarity of these ultra high energy cosmic rays, they must be observed indirectly through the observation of extensive air showers, and the lack of knowledge of hadronic interactions at these energies leads to inherent difficulties in characterizing the properties of the primary particle. A new generation cosmic ray detector, the Pierre Auger Observatory, has been designed to study cosmic rays with energy above $10^{18}$~eV and answer the crucial questions of ultra high energy cosmic ray physics. The Southern Observatory in Argentina has been collecting data since 2004 and its exposure is already larger than that of any previous experiment. After three years of operation, we found strong indications that ultra high energy cosmic rays come from nearby, extragalactic sources, opening a window for charged particle astronomy. In this talk, I will describe the Observatory, our most recent results, and the exciting prospects for the near future. [Preview Abstract] |
Saturday, October 18, 2008 2:18PM - 2:30PM |
J1.00003: Site Selection for the Southern Utah Observatory David Kieda, R. Wayne Springer, Paolo Gondolo, Stephan Lebohec, Paul Ricketts, Chris Zimmer During 2007-2008, the University of Utah performed a survey of various high-altitude sites in southern Utah to select the site for the new 32" Southern Utah Observatory telescope. The site survey process consisted of evaluation of weather and climate databases as well as characterization of atmospheric seeing at each site over several months using several automated SBIG Polaris monitors that were deployed at selected sites. In this talk, I will describe the results of the site survey, including atmospheric seeing measurement histories at several potential sites. I will also describe the final selected site and the timeline for construction and operation of the telescope. [Preview Abstract] |
Saturday, October 18, 2008 2:30PM - 2:54PM |
J1.00004: Gravitational Wave Astronomy: a status report Invited Speaker: The LIGO observatories have recently finished more than a year of observation at design sensitivity. They will be going through an upgrade that will enhance their sensitivity by a factor of two and start a new period of observation in 2009. After that work to install the major upgrades that constitute Advanced LIGO will start. A few years later the LIGO observatories will start operating with an order of magnitude enhanced sensitivity. In this talk I review the most recent results obtained during the last observation period (scientific run number 5): these results although null, are giving interesting upper limits in observational astrophysics. I will discuss the implications they have for the nascent field of Gravitational Wave Astronomy. [Preview Abstract] |
Saturday, October 18, 2008 2:54PM - 3:06PM |
J1.00005: General relativistic effects in galactic rotation velocity profiles Sophia Cisneros The anomalously high galactic rotation velocities deduced from spectroscopic observations have motivated the conjecture of additional Dark Matter. Here we investigate to what extent this picture may be impacted by general relativistic effects. Previous work involving General Relativity has used linearized field equations to arrive at estimates of wavelength shifts arising from spin induced curvature. We show here that, using the fully contravariant 3+1 dimensional wave equation (the D'Alembertian for a Kerr Metric), non-trivial results for observed velocities can be obtained. These velocities are much higher than those obtained from the linearized equations. The Kerr rotation curve is derived from first principles. The wavelength shifts are then weighted by an empirical factor which accounts for difference in curvature of the originating galaxy and the Milky Way. The resulting apparent radial dependence of the velocity is much flatter than obtained in the Keplerian case, which opens the possibility that, for our test galaxy(M33), we have correct estimates of (luminous) matter on the exterior edges, but have only underestimated the mass at the center. This result suggests that general relativistic effects mitigate, or may possibly even obviate the need to invoke the presence of Dark Matter in order to explain the observed apparent velocity profiles. All rotation curves presented are computed with data graciously provided by E.Corbelli and R.Walterbos for M33, taken in the wavelength band of H{\_}alpha. [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