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The evolution of cluster E and S0 galaxies measured from the Fundamental Plane
van Dokkum, Pieter G.; Franx, Marijn; Hjorth, Jens +1 more
Photometry has been obtained for magnitude-limited samples of galaxies in the rich clusters Abell 665 (37 galaxies) and Abell 2218 (61 galaxies). Both clusters have a redshift of 0.18. The limiting magnitude of the samples is 19mag in the I band. Spectroscopy has been obtained for seven galaxies in A665 and nine galaxies in A2218, all of which als…
Highly Ionized High-Velocity Clouds: Intergalactic Gas in the Local Group or Distant Gas in the Galactic Halo?
Sembach, Kenneth R.; Savage, Blair D.; Lu, Limin +1 more
In the course of our studies of the gaseous halo surrounding the Milky Way, we have recently identified several high-velocity clouds (HVCs; VLSR<-100 km s-1) in the directions of Mrk 509 and PKS 2155-304 that have unusual ionization properties. The clouds exhibit strong C IV absorption with little or no detectable low ion …
Coronal hole diagnostics out to 8Rsun
Doyle, J. G.; Teriaca, L.; Banerjee, D.
The Si viii line width measurements and N_e estimates based on SUMER observations are combined with LASCO and UVCS output to provide an overview of its variations with height above a polar coronal hole. From the combined dataset we find a radial dependence of the electron density, in the range 1-2 Rsun as r(-8) , from 2 to 4 Rsun
The Origin of the Narrow-Line Region of Markarian 3: An Overpressured Jet Cocoon
Marconi, A.; Macchetto, F. D.; Capetti, A. +2 more
We have obtained Hubble Space Telescope (HST) Faint Object Camera (FOC) f/48 long-slit optical spectroscopy of the inner 2" of the narrow-line region (NLR) of the Seyfert 2 galaxy Mrk 3 with a spatial resolution of 0.06". Spectra were taken in six locations with the slit approximately perpendicular to the radio axis. In the region cospatial with t…
Ages for Globular Clusters in the Outer Galactic Halo: The Second-Parameter Clusters Palomar 3, Palomar 4, and Eridanus
Bond, Howard E.; Stetson, Peter B.; Richer, Harvey B. +9 more
We have used the Wide Field Planetary Camera 2 on the Hubble Space Telescope to obtain photometry of the outer halo globular clusters Palomar 3, Palomar 4, and Eridanus. These three are classic examples of the ``second-parameter'' anomaly because of their red horizontal-branch morphologies in combination with their low-to-intermediate metallicitie…
The distribution of nearby stars in phase space mapped by Hipparcos. Clustering and streaming among A-F type stars
Bienaymé, O.; Crézé, M.; Chereul, E.
This paper presents the detailed results obtained in the search of density-velocity inhomogeneities in a volume limited and absolute magnitude limited sample of A-F type dwarfs within 125 parsecs of the Sun. A 3-D wavelet analysis is used to extract inhomogeneities, both in the density and velocity distributions. Thus, a real picture of the phase …
The PG X-Ray QSO Sample: Links between the Ultraviolet-X-Ray Continuum and Emission Lines
Ferland, G. J.; Wilkes, B. J.; Wills, D. +4 more
Two sets of relationships relate QSO UV to soft X-ray continua with the broad-line region. These are (i) the Baldwin relationships, which are inverse relationships between the broad-line equivalent width and the continuum luminosity, and (ii) Boroson & Green's optical ``Principal Component 1'' relationships, linking steeper soft X-ray spectra …
A Determination of H0 with the CLASS Gravitational Lens B1608+656. II. Mass Models and the Hubble Constant from Lensing
Koopmans, L. V. E.; Fassnacht, C. D.
We present mass models of the four-image gravitational lens system B1608+656, based on information obtained through VLBA imaging, VLA monitoring, and Hubble Space Telescope (HST) WFPC2 and NICMOS imaging. We have determined a mass model for the lens galaxies that reproduces (1) all image positions within the observational errors, (2) two out of th…
The Eagle Nebula's fingers - pointers to the earliest stages of star formation?
Pilbratt, G. L.; White, G. J.; Holland, W. S. +14 more
Molecular line, millimetre/submillimetre continuum, and mid-IR observations are reported of the opaque fingers which cross the Eagle Nebula. The fingers are surprisingly warm when viewed in the CO J= 3-2 lines, with kinetic temperatures approaching 60 K, although the lines are relatively narrow. Most of the mass in the fingers is concentrated in c…
Space Velocities of Southern Globular Clusters. II. New Results for 10 Clusters
Girard, Terrence M.; van Altena, William F.; López, Carlos E. +1 more
Absolute proper motions have been measured for 10 clusters, in addition to the sample of five clusters presented in an earlier paper. These newly measured clusters are NGC 1904 (M79), NGC 2298, NGC 4590 (M68), NGC 5139 (omega Cen), NGC 5897, NGC 6093 (M80), NGC 6121 (M4), NGC 6144, NGC 6809 (M55), and NGC 7099 (M30). The correction to absolute pro…