Search Publications
The Highest Resolution Chandra View of Photoionization and Jet-Cloud Interaction in the Nuclear Region of NGC 4151
Zezas, A.; Elvis, M.; Fabbiano, G. +4 more
We report high resolution imaging of the nucleus of the Seyfert 1 galaxy NGC 4151 obtained with a 50 ks Chandra High Resolution Camera (HRC) observation. The HRC image resolves the emission on spatial scales of 0farcs5, ~30 pc, showing an extended X-ray morphology overall consistent with the narrow-line region (NLR) seen in optical line emission. …
Dynamic S0 Galaxies: A Case Study of NGC 5866
Wang, Q. Daniel; Li, Zhiyuan; Chen, Yang +1 more
S0 galaxies are often thought to be passively evolved from spirals after star formation is quenched. To explore what is actually occurring in such galaxies, we present a multi-wavelength case study of NGC 5866—a nearby edge-on S0 galaxy in a relatively isolated environment. This study shows strong evidence for dynamic activities in the interstella…
The Dusty Nebula Surrounding HR Car: A Spitzer View
Umana, G.; Fazio, G. G.; Hora, J. L. +3 more
We present mid-IR observations of the Galactic Luminous Blue Variable (LBV) HR Car and its associated nebula carried out with the Spitzer Space Telescope using both Infrared Array Camera and Infrared Spectrograph, as part of a GTO program aimed to study stellar ejecta from evolved stars. Our observations reveal a rich mid-IR spectrum of the inner …
Toward Reconstruction of Coronal Mass Ejection Density from Only Three Points of View
Morgan, H.; Frazin, R. A.; Manchester, W. B., IV +2 more
Understanding the structure of coronal mass ejections (CMEs) is one of the primary challenges in solar astrophysics. White-light coronagraphs make images of line-of-sight projections of the CME electron density (Ne ). The combination of the coronagraphs on the STEREO and SOHO spacecraft provides three simultaneous viewpoints that vary i…
The UV-Mid-IR Spectral Energy Distribution of a z = 1.7 Quasar Host Galaxy
Kochanek, C. S.; Assef, R. J.; Ross, N. R. +2 more
We have measured the spectral energy distribution (SED) of the host galaxy of the zs = 1.7 gravitationally lensed quasar SDSS J1004+4112 from 0.44-8.0 µm (0.16-3.0 µm in the rest frame). The large angular extent of the lensed images and their separation from the central galaxy of this cluster lens allows the images to be res…
Color Bimodality in M87 Globular Clusters
Zepf, Stephen E.; Lauer, Tod R.; Waters, Christopher Z. +1 more
We present an analysis of a 50 orbit Hubble Space Telescope (HST) Advanced Camera for Surveys (ACS) observation of the M87 globular cluster system. We use the extraordinary depth of this data set to test whether the colors and magnitudes show evidence for a mass-metallicity relation in globular cluster populations. We find only a weak or absent re…
Discovery of Fog at the South Pole of Titan
Brown, M. E.; Chen, C.; Ádámkovics, M. +1 more
While Saturn's moon Titan appears to support an active methane hydrological cycle, no direct evidence for surface-atmosphere exchange has yet appeared. The indirect evidence, while compelling, could be misleading. It is possible, for example, that the identified lake features could be filled with ethane, an involatile long-term residue of atmosphe…
The X-ray Detectability of Electron Beams Escaping from the Sun
Krucker, Säm; Lin, Robert P.; Saint-Hilaire, Pascal +1 more
We study the detectability and characterization of electron beams as they leave their acceleration site in the low corona toward interplanetary space through their nonthermal X-ray bremsstrahlung emission. We demonstrate that the largest interplanetary electron beams (gsim1035 electrons above 10 keV) can be detected in X-rays with curre…
The Structure and Origin of Solar Plumes: Network Plumes
Wilhelm, K.; Gabriel, A.; Tison, E. +1 more
This study is based upon plumes seen close to the solar limb within coronal holes in the emission from ions formed in the temperature region of 1 MK, in particular, the band of Fe IX 171 Å from EIT on the Solar and Heliospheric Observatory. It is shown, using geometric arguments, that two distinct classes of structure contribute to apparently simi…
ChaMPlane Deep Galactic Bulge Survey. I. Faint Accretion-driven Binaries in the Limiting Window
van den Berg, Maureen; Grindlay, Jonathan E.; Hong, Jae Sub
We have carried out a deep X-ray and optical survey with Chandra and HST of low-extinction regions in the Galactic bulge. Here we present the results of a search for low-luminosity (LX lsim 1034 erg s-1) accreting binaries among the Chandra sources in the region closest to the Galactic center, at an angular offset …