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CCD Speckle Observations of Binary Stars from the Southern Hemisphere. III. Differential Photometry
Franz, Otto G.; Horch, Elliott; Ninkov, Zoran
Two hundred seventy-two magnitude difference measures of 135 double star systems are presented. The results are derived from speckle observations using the Bessel V and R passbands and a fast readout CCD camera. Observations were taken at two 60 cm telescopes, namely the Helen Sawyer Hogg Telescope, formerly at Las Campanas, Chile, and the Lowell-…
RX J0848+4456: Disentangling a Moderate Redshift Cluster
Papovich, C.; Tozzi, P.; Rosati, P. +7 more
We present a multiwavelength study of RX J0848+4456, a cluster of galaxies discovered through X-ray emission in the ROSAT Deep Cluster Survey. Our observations consist of WFPC2 imaging, optical spectra, and X-ray data collected with the Chandra X-Ray Observatory. We find that RX J0848+4456 consists of an X-ray-emitting cluster of galaxies at a red…
Caltech Faint Galaxy Redshift Survey. XV. Classifications of Galaxies with 0.2<Z<1.1 in the Hubble Deep Field North and its Flanking Fields
Cohen, Judith G.; van den Bergh, Sidney; Crabbe, Christopher
To circumvent the spatial effects of resolution on galaxy classification, the images of 233 objects of known redshift in the Hubble Deep Field (HDF) and its flanking fields that have redshifts in the range 0.20<z<1.10 were degraded to the resolution that they would have had if they were all located at a redshift of z=1.00. As in Paper XIV of…
The Main-Sequence Luminosity Function of Palomar 5 from THE HUBBLE SPACE TELESCOPE
Smith, Graeme H.; Grillmair, Carl J.
A low mass, large core radius, low central concentration, and strong tidal tails suggest that the globular cluster Palomar 5 has lost a large fraction of its initial mass over time. If the dynamical evolution of Pal 5 has been dominated by the effects of mass loss, then theoretical arguments suggest that the luminosity function should be deficient…
Hubble Space Telescope Images of the Ultraluminous Supernova Remnant Complex in NGC 6946
Blair, William P.; Fesen, Robert A.; Schlegel, Eric M.
We present Hubble Space Telescope (HST) narrow-passband Hα and [S II] images and broadband continuum images of the region around an extremely luminous optical and X-ray supernova remnant complex in the spiral galaxy NGC 6946. These images, obtained with the PC1 CCD of the Wide Field Planetary Camera 2, show a circular, limb-brightened shell of dia…
The Massive Star Content of NGC 6822: Ground-Based andHubble Space Telescope Photometry
Massey, Philip; Bianchi, Luciana; Romaniello, Martino +1 more
We investigate the massive star population of NGC 6822 with ground-based UBV photometry covering the whole of the galaxy and HST WFPC2 photometry with filters F255W, F336W, F439W, and F555W of two fields containing very rich and crowded OB associations. The four-band WFPC2 photometry is used to derive Teff and E(B-V). H-R diagrams are c…
Multicolor Observations of the Hubble Deep Field South
Fontana, Adriano; Grazian, Andrea; Bianchi, Simone +6 more
We present a deep multicolor (U, B, V, I, Js, H, Ks) catalog of galaxies in the Hubble Deep Field South, based on observations obtained with the HST WFPC2 in 1998 and VLT-ISAAC in 1999. The photometric procedures were tuned to derive a catalog optimized for the estimation of photometric redshifts. In particular we adopted a ``conservative'' detect…
Compact Star Clusters in M81. I. Data from Hubble Space Telescope Wide Field Planetary Camera 2 Imaging
Chandar, Rupali; Ford, Holland C.; Tsvetanov, Zlatan
In this paper, we present the discovery of 114 compact star clusters in the nearby spiral galaxy M81 from B-, V-, and I-band Hubble Space Telescope Wide Field Planetary Camera 2 imaging in eight fields, covering a total area of ~40 arcmin2. The fields sample a variety of environments (both spiral and interarm regions), as well as a rang…
Spatially Resolved STIS Spectra of WR+OB Binaries with Colliding Winds
Moffat, Anthony F. J.; Lépine, Sébastien; Shara, Michael M. +2 more
We present spatially resolved spectra of the visual WR+OB massive binaries WR 86, WR 146, and WR 147, obtained with the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope. The systems are classified as follows: WR 86=WC 7+B0 III, WR 146=WC 6+O8 I-IIf, WR 147=WN 8+O5-7 I-II(f). Both WR 146 and WR 147 are known to have strong n…
Sr II and [Sr II] Emission in the Ejecta of η Carinae
Gull, Theodore R.; Hartman, Henrik; Davidson, Kris +3 more
We have discovered four extremely surprising emission lines of strontium in ejecta near η Carinae. Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph (STIS) observations made in 1999 show two narrow features whose wavelengths correspond to the forbidden transitions of Sr II, and we have found no other plausible identification for th…