Search Publications
INTEGRAL SPI Observation of the Galactic Central Radian: Contribution of Discrete Sources and Implication for the Diffuse Emission
Bouchet, L.; Terrier, R.; Diehl, R. +4 more
The INTEGRAL observatory has been performing a deep survey of the Galactic central radian since 2003, with the goal of both extracting a catalog of sources and gaining insight into the Galactic diffuse emission. This paper concentrates on the estimation of the total point-source emission contribution. It is now clear that unresolved point sources …
Disk-integrated Intensity Pseudomodes Measured by SOHO/VIRGO
Jiménez-Reyes, S. J.; García, R. A.; Jiménez, A.
The high-frequency spectrum above the acoustic cutoff frequency (νac) of the solar atmosphere has been observed in velocity measurements at low and high angular degrees and reveals significant evidence for the presence of pseudomodes characterized by their equally spaced signal. In this paper we study this region of the spectra using fo…
Central Blue Clumps in Elliptical Galaxies of the Hubble Ultra Deep Field
Elmegreen, Bruce G.; Elmegreen, Debra Meloy; Ferguson, Thomas E.
Elliptical galaxies larger than 10 pixels in the Hubble Ultra Deep Field (UDF) were surveyed for internal structure; 30 out of 100 in a sample of 884 morphologically classified galaxies exhibit large blue clumps near their centers. Unsharp-masked images of the clearest cases are presented. The distributions of the clumps on color-color and color-m…
Supernova Remnants in the Magellanic Clouds. V. The Complex Interior Structure of the N206 Supernova Remnant
Gruendl, R. A.; Chu, Y. -H.; Guerrero, M. A. +4 more
The N206 supernova remnant (SNR) in the Large Magellanic Cloud has long been considered a prototypical ``mixed morphology'' SNR. Recent observations, however, have added a new twist to this familiar plot: an elongated, radially oriented radio feature seen in projection against the SNR face. Utilizing the high resolution and sensitivity available w…
A Simultaneous RXTE and XMM-Newton Observation of the Broad-Line Radio Galaxy 3C 111
Eracleous, Michael; Gliozzi, Mario; Mushotzky, Richard F. +2 more
We present the results of simultaneous XMM-Newton and RXTE observations of the broad-line radio galaxy 3C 111. We find that the Compton reflection bump is extremely weak; however, broad residuals are clearly present in the spectrum near the Fe Kα emission line region. When fitted with a Gaussian emission line, the feature has an equivalent width o…
The Vela Pulsar in the Ultraviolet
Pavlov, George G.; Kargaltsev, Oleg; Romani, Roger W.
We describe time-tagged observations of the Vela pulsar (PSR B0833-45) with the HST STIS MAMA UV detectors. Using an optimal extraction technique, we obtain an NUV light curve and crude FUV phase-resolved spectra. The pulse is dominated by complex nonthermal emission at all phases. We obtain approximate spectral indices for the brightest pulse com…
The Absorption Signature of Six Mg II-selected Systems over 0.5 <= z <= 0.9
Charlton, Jane C.; Churchill, Christopher W.; Ding, Jie
We present the results of photoionization modeling of six Mg II-selected absorption systems, at redshift 0.5<=z<=0.9, along lines of sight toward three quasars: PG 1241+176, PG 1248+401, and PG 1317+274. These are part of a larger sample of ~20 Mg II absorbers at intermediate redshift, which facilitates a survey of the properties of, and pro…
Large-Scale CO and [C I] Emission in the ρ Ophiuchi Molecular Cloud
Kulesa, Craig A.; Hungerford, Aimee L.; Walker, Christopher K. +2 more
We present a comprehensive study of the ρ Ophiuchi molecular cloud that addresses aspects of the physical structure and condition of the molecular cloud and its photodissociation region (PDR) by combining far-infrared and submillimeter-wave observations with a wide range of angular scale and resolution. We present 1600 arcmin2 maps (2.3…
X-Ray Luminosity and Absorption Column Fluctuations in the H2O Maser Galaxy NGC 4258 from Weeks to Years
Filippenko, Alexei V.; Greenhill, Lincoln J.; Fruscione, Antonella +3 more
We report monitoring of the 0.3-10 keV spectrum of NGC 4258 with the XMM-Newton Observatory at five epochs over 1.5 yr. We also report reprocessing of an overlapping four-epoch series of archival Chandra observations (0.5-10 keV). By including earlier ASCA and BeppoSAX observations, we present a new, 9 year time series of models fitted to the X-ra…
The 10 µm Feature of M-Type Stars in the Large Magellanic Cloud and the Dust Condensation Sequence
Abraham, P.; Speck, A. K.; Dijkstra, C. +1 more
We present 7-14 µm Infrared Space Observatory (ISO) spectroscopy of 12 M-type evolved stars in the Large Magellanic Cloud (LMC), in order to study the dust mineralogy and condensation process around these stars. The sample stars show a broad dust feature in the 7-14 µm region, which is seen in either emission or (self-) absorption. The…