Astrophysics Seminars

ABSTRACT: A detailed and precise understanding of the formation of neutral atomic hydrogen is necessary to predict the spectrum of microwave anisotropies. New experiments like Planck and ACT will gain considerable leverage on the cosmological...

ABSTRACT: In addition to the major planets, the solar system contains a large number of so-called small bodies in dynamically distinct reservoirs. These include the main-belt asteroids, main-belt comets, Trojans, Centaurs, irregular satellites, the...

ABSTRACT: Observations of the gamma-ray sky by the Fermi Gamma-ray Space Telescope have revealed a striking sharp-edged, double-lobed structure in 1-100 GeV gamma rays, centered on the Galactic Center and extending 50 degrees north and south of the...

ABSTRACT: Herschel Space Observatory, a 3.5m far-infrared telescope, was launched 14 May 2009, and is now located at the Earth-Sun L2 point, carrying out imaging and spectroscopy at wavelengths from 70um to 500um with LHe-cooled detectors. For...

ABSTRACT: We take a fresh look at high energy radioactive nuclei data reported in the 90's and at the positron data recently reported by PAMELA. Our aim is to study the model independent implications of these data for the propagation time scales of...

ABSTRACT: Core-collapse supernovae are a puzzle that has taxed theorists and computational science for half a century. Such explosions, the source of much of the heavy elements in the Universe and the birthplace of neutron stars and stellar-mass...

ABSTRACT: I briefly review recent Auger results and the likely astrophysical sources responsible, such as gamma-ray bursts, active galactic nuclei, magnetars and hypernoave. I then discuss the secondary GeV-TeV gamma-ray and neutrino signatures of...

ABSTRACT: The cosmic rays (CRs) in star-forming galaxies dominate their emission at gamma-ray and radio wavelengths. The observed linear correlation between the nonthermal radio emission and the thermal infrared emission of galaxies, the far...

ABSTRACT: The discovery of the accelerating expansion of the Universe poses a profound challenge to our understanding of fundamental physics. I will describe our group's ongoing efforts to determine the nature of the Dark Energy, including next...