Search Publications
GRB 010921: Strong Limits on an Underlying Supernova from the Hubble Space Telescope
Piro, L.; Axelrod, T. S.; Frontera, F. +24 more
GRB 010921 was the first HETE-2 gamma-ray burst (GRB) to be localized via its afterglow emission. The low redshift of the host galaxy, z=0.451, prompted us to undertake intensive multicolor observations with the Hubble Space Telescope with the goal of searching for an underlying supernova (SN) component. We do not detect any coincident SN to a lim…
Probing the Size of Low-Redshift Lyα Absorbers
Stocke, John T.; Giroux, Mark L.; Ganguly, Rajib +1 more
The 3C 273 and RX J1230.8+0115 sight lines probe the outskirts of the Virgo Cluster at physical separations between the sight lines of 200 and 500 h-170 kpc. We present an analysis of available Hubble Space Telescope STIS echelle and Far-Ultraviolet Spectroscopic Explorer (FUSE) UV spectroscopy of RX J1230.8+0115, in which we…
Stellar Hydrodynamics in Radiative Regions
Rigby, Jane R.; Knierman, Karen A.; Young, Patrick A. +1 more
We present an analysis of the response of a radiative region to waves generated by a convective region of the star; this wave treatment of the classical problem of ``overshooting'' gives extra mixing relative to the treatment traditionally used in stellar evolutionary codes. The interface between convectively stable and unstable regions is dynamic…
The Homogeneity of Interstellar Krypton in the Galactic Disk
Meyer, David M.; Cartledge, Stefan I. B.; Lauroesch, J. T.
We present an analysis of high-resolution Hubble Space Telescope Space Telescope Imaging Spectrograph (STIS) observations of Kr I λ1236 absorption in seven sight lines that probe a variety of interstellar environments. In combination with krypton and hydrogen column densities derived from current and archival STIS and Far-Ultraviolet Spectroscopic…
Temporal Evolution of a Streamer Complex: Coronal and in Situ Plasma Parameters
Parenti, S.; Romoli, M.; Riley, P. +5 more
We report on observations acquired by the Ultraviolet Coronagraph Spectrometer (UVCS) aboard the Solar and Heliospheric Observatory (SOHO), from 2000 June 10 to June 17 at the time of a SOHO-Sun-Ulysses quadrature. UVCS took data at 1.6 and 1.9 Rsolar with a slit normal to the solar radius and centered along the radial to Ulysses. A str…
Detection of Pulsed X-Ray Emission from XMM-Newton Observations of PSR J0538+2817
Cropper, M.; McGowan, K. E.; Kennea, J. A. +5 more
We report on the XMM-Newton observations of the 143 ms pulsar PSR J0538+2817. We present evidence for the first detections of pulsed X-rays from the source at a frequency that is consistent with the predicted radio frequency. The pulse profile is broad and asymmetric, with a pulse fraction of 18%+/-3%. We find that the spectrum of the source is we…
Galaxies under the Cosmic Microscope: A Gemini Multiobject Spectrograph Study of Lensed Disk Galaxy 289 in A2218
Smail, I.; Kneib, J. -P.; Smith, Graham P. +7 more
In this paper, we exploit the gravitational potential of the rich cluster A2218 as a magnifying glass. We demonstrate that the magnification due to the cluster allows us to observe distant background galaxies at a comparable level of detail to galaxies at z~0.1. Using the Gemini Multiobject Spectrograph (GMOS) integral field unit (IFU) on Gemini N…
Ultraviolet Spectroscopy of Narrow Coronal Mass Ejections
Raymond, J. C.; Dobrzycka, D.; Biesecker, D. A. +2 more
We present Ultraviolet Coronagraph Spectrometer (UVCS) observations of five narrow coronal mass ejections (CMEs) that were among 15 narrow CMEs originally selected by Gilbert and coworkers. Two events (1999 March 27, April 15) were ``structured,'' i.e., in white-light data they exhibited well-defined interior features, and three (1999 May 9, May 2…
The 2001 April Burst Activation of SGR 1900+14: X-Ray Afterglow Emission
Hurley, K.; Costa, E.; Mereghetti, S. +8 more
After nearly two years of quiescence, the soft gamma-ray repeater SGR 1900+14 again became burst-active on 2001 April 18, when it emitted a large flare, preceded by few weak and soft short bursts. After having detected the X- and gamma-prompt emission of the flare, BeppoSAX pointed its narrow field X-ray telescopes to the source in less than 8 hr.…
A Scattered Light Echo around SN 1993J in M81
Bregman, Joel N.; Seitzer, Patrick; Liu, Ji-Feng
A light echo around SN 1993J was observed 8.2 yr after explosion by a Hubble Space Telescope Wide Field Planetary Camera 2 observation, adding to the small family of supernovae with light echoes. The light echo was formed by supernova light scattered from a dust sheet that lies 220 pc away from the supernova, 50 pc thick along the line of sight, a…