Search Publications
The Detection of Circumnuclear X-Ray Emission from the Seyfert Galaxy NGC 3516
Nandra, K.; Turner, T. J.; Kraemer, S. B. +7 more
We present the first high-resolution, X-ray image of the circumnuclear regions of the Seyfert 1 galaxy NGC 3516, using the Chandra X-ray Observatory (CXO). All three of the CXO observations reported were performed with one of the two grating assemblies in place, and here we restrict our analysis to undispersed photons (i.e., those detected in the …
Energetic Particle Abundances as Probes of an Interplanetary Shock Wave
Reames, D. V.; Tylka, A. J.
We examine the unique abundance variations of Fe/O and He/H in solar energetic particles from a W09 event of 2001 April 10 that have leaked through the flank of an interplanetary shock launched from W04 on April 9. Shock waves from both events reached the Wind spacecraft on April 11. During the second event, both Fe/O and He/H began at low values …
Phase and Gain Relations between Low-Degree Intensity and Velocity Acoustic Modes during the Solar Activity Cycle
Jiménez, Antonio
Phase and gain relations between low-degree acoustic modes measured as intensity and velocity fluctuations have been carried out using various instruments and techniques. The helioseismic instrument aboard the Solar and Heliospheric Observatory (SOHO) satellite provides an opportunity to observe solar oscillations in intensity and velocity under t…
Extreme Ultraviolet Explorer Phase-resolved Spectroscopy of V834 Centauri
Mauche, Christopher W.
The Extreme Ultraviolet Explorer (EUVE) satellite was employed for 5.46 days, beginning on 1999 February 9.03 UT, to acquire phase-resolved EUV photometric and spectroscopic observations of the AM Her type cataclysmic variable V834 Centauri. The resulting data are superior to those obtained by EUVE beginning on 1993 May 28.14 UT, because the sourc…
Constraints on Cool Gas in Rich Clusters of Galaxies
Miller, Eric D.; Bregman, Joel N.; Knezek, Patricia M.
Cool gas should be present in galaxy clusters due to stripping of galactic gas, in-fall onto the cluster, and from cooling flows. We have searched for this gas through metal resonance absorption lines from low-ionization gas toward six background quasars. Both cooling-flow and non-cooling-flow clusters were observed, with lines of sight ranging fr…
Detection of a Vibration-Rotation Emission Line of Hydrogen Deuteride toward Orion Peak 1: Excitation Coupling of HD to H2
Bertoldi, F.; Geballe, T. R.; Timmermann, R. +2 more
The 2.46 µm v=1-0 R(5) line of deuterated molecular hydrogen (HD) has been detected in the Orion Peak 1 shock emission region, at a surface brightness of (8.5+/-2.1)×10-9Wm-2sr-1 over a 6 arcsec2 area. Comparison of the column density of HD (v=1,J=6) with the column density of HD (v=0,J=6) previous…
Globular Cluster Systems in Four Brightest Cluster Galaxies: A262, A3560, A3565, and A3742
Harris, William E.; Okoń, Waldemar M. M.
We have used deep I-band (F814W) images from the Hubble Space Telescope archive to study the globular cluster systems around the brightest cluster galaxies (BCGs) in A262, A3560, A3565, and A3742. Three of these BCGs have inner dust lanes and peculiar structural features that indicate past histories of low-level interaction and accretion. The deep…
Mid-Infrared Identification of Faint Submillimeter Sources
Kawara, K.; Cowie, L. L.; Matsuhara, H. +4 more
Faint submillimeter sources detected with the Submillimeter Common-User Bolometer Array on the James Clerk Maxwell Telescope have faced an identification problem due to the telescope's broad beam profile. Here we propose a new method to identify such submillimeter sources with a mid-infrared image having a finer point-spread function. The Infrared…
On the Low-Mass End of the Globular Cluster Luminosity Function
Smith, Graeme H.; Burkert, Andreas
The low-mass globular cluster luminosity function (GCLF) in the Milky Way and in two elliptical galaxies is investigated. We find that the power-law slope of the Milky Way GCLF depends on the cluster concentration c. The origin of this trend is explored within the framework of a GC mass-loss model. It is also found that the low-mass GCLF of the Mi…
Matching the Observed Star Formation Intensity Distribution with Empirical Laws
Thompson, Rodger I.
This Letter matches the shape of the star formation intensity distribution function to empirical laws such as the Schmidt law. The shape of the distribution at a redshift of 1 is reproduced from the empirical Schmidt law with a critical density, a Schechter distribution of galaxy masses, and the assumption that star formation occurs mainly in expo…