Search Publications
Hubble Space Telescope Wide Field Planetary Camera 2 Imaging of Shocks in Superbubbles
Chu, You-Hua; Gruendl, Robert A.; Chen, C. -H. Rosie +1 more
Bright X-ray emission has been detected in superbubbles in the Large Magellanic Cloud (LMC), and it is suggested that supernova remnants (SNRs) near the inner-shell walls are responsible for this X-ray emission. To identify SNR shocks in superbubble interiors, we have obtained Hubble Space Telescope Wide Field Planetary Camera 2 emission-line imag…
The Globular Cluster System in the Inner Region of the Giant Elliptical Galaxy NGC 4472
Lee, Myung Gyoon; Kim, Eunhyeuk
We present a study of globular clusters in the inner region of the giant elliptical galaxy NGC 4472, based on the HST/WFPC2 archive data. We have found about 1560 globular cluster candidates at the galactocentric radius r<4', most of which are located within r=1.1‧. A V-(V-I) diagram of these objects shows a dominant vertical structure obviousl…
Radial Color Gradient and Main-Sequence Mass Segregation in M30 (NGC 7099)
Guhathakurta, Puragra; Howell, Justin H.; Tan, Amy
It has long been known that the post-core-collapse globular cluster M30 (NGC 7099) has a bluer-inward color gradient, and recent work suggests that the central deficiency of bright red giant stars does not fully account for this gradient. This study uses Hubble Space Telescope Wide Field Planetary Camera 2 images in the F439W and F555W bands, alon…
The Starburst-Interstellar Medium Interaction in NGC 1569. I. Location and Nature of HE II Sources UsingHubble Space Telescope WFPC2 Imagery
Dufour, Reginald J.; Buckalew, Brent A.; Walter, Donald K. +1 more
We present the detection of He II sources in the Im galaxy NGC 1569 from Hubble Space Telescope WFPC2 imagery. Of the 15 detections, seven were Wolf-Rayet stars, five were stellar clusters with associated He II emission, and three were sources of unknown origin. The detected Wolf-Rayet stars' colors and magnitudes are similar to those of Large Mag…
Counts and Sizes of Galaxies in the Hubble Deep Field South: Implications for the Next Generation Space Telescope
Gardner, Jonathan P.; Satyapal, Shobita
Science objectives for the Next Generation Space Telescope (NGST) include a large component of galaxy surveys, both imaging and spectroscopy. The Hubble Deep Field data sets include the deepest observations ever made in the ultraviolet, optical, and near-infrared, reaching depths comparable to that expected for NGST spectroscopy. We present the so…
CCD Speckle Observations of Binary Stars from the Southern Hemisphere. II. Measures from the Lowell-Tololo Telescope during 1999
Franz, Otto G.; Horch, Elliott; Ninkov, Zoran
Speckle observations of 145 double stars and suspected double stars are presented and discussed. On the basis of multiple observations, a total of 280 position angle and separation measures are determined, as well as 23 high-quality nondetections. All observations were taken with the (unintensified) Rochester Institute of Technology fast-readout C…
The 0.33 Day DA Plus DME Binary BPM 6502
Vennes, Stéphane; Dupuis, Jean; Kawka, Adela +1 more
We have obtained a series of spectroscopic measurements of the high proper-motion star BPM 6502 showing Balmer emission superposed upon the absorption lines. Radial velocity measurements determined by tracing optical absorption and emission lines show that the star is a binary system comprised of a DA white dwarf and an M dwarf with an orbital per…
Comparisons of the Tycho-2 Catalogue Proper Motions with HIPPARCOS and ACT
Makarov, V. V.; Urban, S. E.; Wycoff, G. L.
The recently released Tycho-2 Catalogue is expected to supersede the currently used catalogs based on the Tycho data, specifically, the ACT Reference Catalog and the Tycho Reference Catalogue. Here the proper motions of the newly released Tycho-2 Catalogue are compared with those of the Hipparcos Catalogue and the ACT Reference Catalog. Tycho-2 is…
Variable Galaxies in the Hubble Deep Field
Phillips, M. M.; Gilliland, Ronald L.; Sarajedini, Vicki L.
We present results from a study to detect variable galaxies in the Hubble Deep Field North (HDF-N). The goal of this project is to investigate the number density of active galactic nuclei (AGNs) at z~=1 through the detection of variable galaxy nuclei. The advantage of the Hubble Space Telescope is its ability to do accurate photometry within small…
The Very Low Mass Component of the Gliese 105 System
Butler, R. Paul; Fischer, Debra A.; Marcy, Geoffrey W. +4 more
Multiple-epoch, multicolor images of the astrometric binary Gliese 105A and its very low mass companion Gliese 105C have been obtained using the Hubble Space Telescope's Wide Field Planetary Camera 2 (WFPC2) and near-infrared camera and multiobject spectrometer (NICMOS). The optical and near-infrared colors of Gl 105C strongly suggest a spectral t…