Search Publications
Distinguishing Local and Global Influences on Galaxy Morphology: A Hubble Space Telescope Comparison of High and Low X-Ray Luminosity Clusters
Kneib, J. -P.; Smith, G. P.; Smail, Ian +6 more
We present a morphological analysis of 17 X-ray-selected clusters at z~0.25, imaged uniformly with the Hubble Space Telescope Wide Field Planetary Camera 2 (WFPC2). Eight of these clusters comprise a subsample selected for their low X-ray luminosities (<~1044 ergs s-1), called the low-LX sample. The remaining ni…
On the Temperature Structure of M87
Molendi, Silvano
We revisit the XMM-Newton observation of M87, focusing our attention on the temperature structure. We find that spectra for most regions of M87 can be adequately fitted by single-temperature models. Only in a few regions, which are cospatial with the east and southwest radio arms, do we find evidence of a second temperature. The cooler component (…
The Timing of Flares Associated with the Two Dynamical Types of Solar Coronal Mass Ejections
Golub, L.; Zhang, M.; Burkepile, J. +1 more
In this Letter, we consider a sample of Transition Region and Coronal Explorer flare-associated solar coronal mass ejections (CMEs) and study the timing behavior of the flares associated with fast or slow CMEs. We find that flares associated with fast CMEs tend to happen within half an hour of the CME onsets, while the timing of flares associated …
The Broadband Afterglow of GRB 980329
Price, P. A.; Harrison, F. A.; Galama, T. J. +15 more
We present radio observations of the afterglow of the bright γ-ray burst GRB 980329 made between 1 month and several years after the burst, a reanalysis of previously published submillimeter data, and late-time optical and near-infrared (NIR) observations of the host galaxy. From the absence of a spectral break in the optical/NIR colors of the hos…
Solar and Heliospheric Observatory Ultraviolet Coronagraph Spectrometer and Yohkoh Soft X-Ray Telescope Observations of the High-Temperature Corona above an Active Region Complex
Fineschi, Silvano; Raymond, John C.; Li, Jing +4 more
We present the results of Solar and Heliospheric Observatory Ultraviolet Coronagraph Spectrometer (SOHO/UVCS) and Yohkoh Soft X-Ray Telescope (SXT) observations above an active region complex (AR 8194, 8195, and 8198) at the southeast limb on 1998 April 6-7. This active region complex appears to be the base of a small streamer seen by the Large An…
XMM-Newton Detection of Hard X-Ray Emission in the Nitrogen-Type Wolf-Rayet Star WR 110
Skinner, Stephen L.; Zhekov, Svetozar A.; Güdel, Manuel +1 more
We have used the excellent sensitivity of XMM-Newton to obtain the first high-quality X-ray spectrum of a Wolf-Rayet (W-R) star that is not known to be a member of a binary system. Our target, the nitrogen-type star WR 110 (HD 165688), was also observed and detected with the Very Large Array at four different frequencies. The radio flux density in…
The X-Ray Source at the Center of the Cassiopeia A Supernova Remnant
Tiengo, A.; Mereghetti, S.; Israel, G. L.
We present the first results of an XMM-Newton observation of the central X-ray source in the Cas A supernova remnant. The spectrum can be fitted equally well with an absorbed steep power law (αph~3, NH~1.5×1022 cm-2) or with a bremsstrahlung with temperature kT~2.4 keV and NH~1022 c…
Hubble Space Telescope/NICMOS Observations of Terzan 5: Stellar Content and Structure of the Core
Cohn, Haldan N.; Lugger, Phyllis M.; Edmonds, Peter D. +1 more
We report results from Hubble Space Telescope/NICMOS imaging of the extremely dense core of the globular cluster Terzan 5. This highly obscured bulge cluster contains a low-mass X-ray binary and at least two millisecond pulsars, with evidence for a large millisecond pulsar population. It has been estimated to have one of the highest collision rate…
X-Ray Bright Points and Photospheric Bipoles during Cycles 22 and 23
Pevtsov, Alexei A.; Sattarov, Isroil; Hojaev, Alisher S. +1 more
We use the Yohkoh soft X-ray telescope (SXT) full-disk images made from 1993 to 2000 to manually identify X-ray bright points (XBPs). We also employ the National Solar Observatory (Kitt Peak) full-disk longitudinal magnetograms made between 1992 April and 2001 April and an automatic procedure to identify photospheric bipoles whose magnetic field s…
Thermal Pressures in Neutral Clouds inside the Local Bubble, as Determined from C I Fine-Structure Excitations
Jenkins, Edward B.
High-resolution spectra covering the absorption features from interstellar C I were recorded for four early-type stars with spectrographs on the Hubble Space Telescope, in a program to measure the fine-structure excitation of this atom within neutral clouds inside or near the edge of the Local Bubble, a volume of hot (T~106K) gas that e…