Search Publications
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…
XMM-Newton observation of the BAL Quasar PHL 5200:. The big surprise
Brinkmann, W.; Gliozzi, M.; Ferrero, E.
XMM-Newton observations of the BAL quasar PHL 5200 revealed that the X-ray emission attributed to the quasar originates from a nearby, optically unidentified radio source. Although visible in X-rays as well the flux from PHL 5200 is by a factor ga 20 smaller than previously anticipated. Thus most of the scenarios for a physical interpretation of t…
Filling factors and magnetic field strengths of nanoflare-heated coronal active regions: Yohkoh and MDI observations
Yashiro, S.; Jain, R.
The scaling laws describing the relationship between thermal and magnetic properties of active regions are derived using the concept that solar coronal active regions are heated by numerous small flare-like events (nanoflares). Thus, a coronal active region is viewed as an ensemble of hot elementary filaments created within the coronal magnetic fi…
A Spectrographic Study of the Interacting Eclipsing Binary RY Scuti: An Episode in the Rapid Mass Loss Stage or a Protoplanetary Nebula?
Sahade, J.; West, R. M.; Skul'Sky, M. Yu.
RY Scuti, the 11-day [Fe III] eclipsing binary, has been reinvestigated on the basis of spectrographic material obtained in Chile at the European Southern Observatory, La Silla, and at the Cerro Tololo Interamerican Observatory, covering the spectral regions 3400-5150 Å and 5700-6700 Å . Ultraviolet IUE observations were also analyzed. The spectru…
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…
Cassini-Huygens Investigations of Satellite Surfaces and Interiors
Soderblom, Laurence A.; Lunine, Jonathan I.
The Saturnian system contains 18 known satellites ranging from 10 km to 2575 km in radius. In bulk properties and surface appearance these objects show less regularity than the sparser Jupiter system. The Galilean-sized moon Titan sports a dense atmosphere of nitrogen and methane which renders surface observations difficult, but also makes this mo…
Spectral energy distributions of five FR I radio galaxies
Capetti, A.; Chiaberge, M.; Celotti, A. +2 more
We discuss the multi-wavelength properties of the radio galaxies 3C 31, 3C 264, 3C 270, 3C 465 and NGC 7052. The data have been deduced from observations with the VLBI/VLA arrays, HST and ROSAT. The SED of these sources, when compared with that of BL Lacs shows that beaming effects are important, but are not enough—in the simplest scenario—to expl…
A Multi-Band Photometric Study of Tidal Debris in a Compact Group of Galaxies: Seyfert's Sextet
Nagao, Tohru; Taniguchi, Yoshiaki; Sanders, David B. +4 more
In order to investigate the properties of the prominent tidal debris feature extending to the northeast of a compact group of galaxies, Seyfert's Sextet, we analyzed multi-band (U, B, V, VR, R, I, J, H, and K') photometric imaging data and obtained the following results: 1) The radial surface brightness distribution of this tidal debris in Seyfert…
Hubble Space Telescope NICMOS Imaging of the Core of M87
Rieke, Marcia J.; Corbin, Michael R.; O'Neil, Earl
We present broadband 1.1, 1.6, and 2.2 µm images and a 2.37 µm narrowband image of the inner 19" of the nearby radio galaxy M87, obtained with the Near Infrared Camera and Multi-Object Spectrometer of the Hubble Space Telescope (HST). The isophotes of the broadband images are almost perfectly circular to within approximately 0.5" (~50 …
The Nature of [Ar III]-Bright Knots in the Crab Nebula
Fesen, Robert A.; Schaller, Emily L.
The kinematic and morphological properties of a string of [Ar III]-bright knots in the Crab Nebula are examined using 1994-1999 Hubble Space Telescope (HST) Wide Field Planetary Camera 2 images of the remnant. We find that five southern [Ar III]-bright knots exhibit ordinary radial motions away from the nebula's center of expansion with magnitudes…