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The Local Lyα Forest. III. Relationship between Lyα Absorbers and Galaxies, Voids, and Superclusters
Shull, J. Michael; Stocke, John T.; Penton, Steven V.
In this paper we use large-angle, nearby galaxy redshift surveys to investigate the relationship between the 81 low-redshift Lyα absorbers in our Hubble Space Telescope GHRS survey and galaxies, superclusters, and voids. In a subsample of 46 Lyα absorbers located in regions where the 2000 February 8 CfA catalog is complete down to at least L* gala…
Spiral Galaxies with HST/NICMOS. I. Nuclear Morphologies, Color Maps, and Distinct Nuclei
Stiavelli, Massimo; de Zeeuw, P. Tim; Carollo, C. Marcella +2 more
This is the first of two papers where we present the analysis of an HST/NICMOS2 near-infrared (NIR) snapshot survey in the F160W (H) filter for a sample of 78 spiral galaxies selected from the UGC and ESOLV catalogs. For 69 of these objects we provide nuclear color information derived by combining the H data either with additional NICMOS F110W (J)…
The Stellar Velocity Dispersion of the Lens Galaxy in MG 2016+112 at z=1.004
Treu, Tommaso; Koopmans, Léon V. E.
We present a direct measurement of the stellar velocity dispersion of the early-type lens galaxy D in the system MG 2016+112 (z=1.004), determined from a spectrum obtained with the Echelle Spectrograph and Imager on the W. M. Keck II Telescope, as part of the Lenses Structure and Dynamics Survey. We find a velocity dispersion of σap=304…
Chandra observations of RX J1347.5-1145: the distribution of mass in the most X-ray-luminous galaxy cluster known
Fabian, A. C.; Allen, S. W.; Schmidt, R. W.
We present Chandra observations of RX J1347.5-1145, the most X-ray-luminous cluster of galaxies known. We report the discovery of a region of relatively hot, bright X-ray emission, located approximately 20 arcsec to the south-east of the main X-ray peak at a position consistent with the region of enhanced Sunyaev-Zel'dovich effect reported recentl…
Chandra Observations of the Lensing Cluster EMSS 1358+6245: Implications for Self-interacting Dark Matter
Garmire, G. P.; Bautz, M. W.; Arabadjis, J. S.
We present Chandra observations of EMSS 1358+6245, a relaxed cooling flow cluster of galaxies at z=0.328. We employ a new deprojection technique to construct temperature, gas, and dark matter profiles. We confirm the presence of cool gas in the cluster core, and our deprojected temperature profile for the hot component is isothermal over 30kpc<…
Energy Distribution of Microevents in the Quiet Solar Corona
Krucker, Säm; Benz, Arnold O.
Recent imaging observations of EUV line emissions have shown evidence for frequent flarelike events in a majority of the pixels in quiet regions of the solar corona. The changes in coronal emission measure indicate impulsive heating of new material to coronal temperatures. These heating or evaporation events are candidate signatures of ``nanoflare…
Variability of magnetospheric storms driven by different solar wind perturbations
Koskinen, Hannu E. J.; Schwenn, Rainer; Huttunen, K. Emilia J.
We have investigated the solar wind drivers of magnetic storms during the rising phase of solar cycle 23 from January 1996 to December 1999. We used observations of coronal mass ejections (CMEs) by the Large Angle and Spectrometric Coronagraph instrument on SOHO and in situ solar wind observations by Wind, IMP 8, and ACE spacecraft. The storms wer…
Flare waves observed in Helium I 10 830 Å. A link between Hα Moreton and EIT waves
Vršnak, B.; Hanslmeier, A.; Warmuth, A. +1 more
Three traveling disturbances recorded in the absorption line of Helium I at 10 830 Å, (He I), analogous to Hα Moreton waves, are analyzed. The morphology and kinematics of the wavefronts are described in detail. The He I wave appears as an expanding arc of increased absorption roughly corresponding to the Hα disturbance, although not as sharply de…
An XMM-Newton Study of the 401 Hz Accreting Pulsar SAX J1808.4-3658 in Quiescence
Campana, S.; Mereghetti, S.; Stella, L. +6 more
SAX J1808.4-3658 is a unique source, being the first low-mass X-ray binary showing coherent pulsations at a spin period comparable to that of millisecond radio pulsars. Here we present an XMM-Newton observation of SAX J1808.4-3658 in quiescence, the first that assessed its quiescent luminosity and spectrum with a good signal-to-noise ratio. XMM-Ne…
The initial conditions of isolated star formation - V. ISOPHOT imaging and the temperature and energy balance of pre-stellar cores
Ward-Thompson, D.; André, P.; Kirk, J. M.
ISO data taken with the long-wavelength imaging photo-polarimeter ISOPHOT are presented of 18 pre-stellar cores at three far-infrared wavelengths, 90, 170 and 200µm. Most of the cores are detected clearly at 170 and 200µm, but only one is detected strongly at 90µm, indicating that mostly they are very cold, with typical temperatu…