Search Publications
The Resolved Stellar Populations in NGC 1705
Leitherer, Claus; Greggio, L.; Tosi, M. +4 more
We present HST photometry of the resolved stellar population in the dwarf irregular galaxy NGC 1705. The galaxy has been observed with both WFPC2 and NICMOS, and successful images have been obtained in the F555W, F814W, F110W, and F160W bands. The optical fields cover most of the galaxy, while the infrared field (NIC2) maps only its central region…
Radial Velocity Studies of Close Binary Stars. V.
Rucinski, Slavek M.; Lu, Wenxian; Mochnacki, Stefan W. +2 more
Radial velocity measurements and sine-curve fits to the orbital velocity variations are presented for the fifth set of 10 close binary systems: V376 And, EL Aqr, EF Boo, DN Cam, FN Cam, V776 Cas, SX Crv, V351 Peg, EQ Tau, and KZ Vir. All systems are double-lined, spectroscopic contact binaries (KZ Vir may be a low-inclination, close, noncontact bi…
A K-band-Selected Photometric Redshift Catalog in the Hubble Deep Field South: Sampling the Rest-Frame V Band to z =3
Franx, Marijn; Labbé, Ivo; van Dokkum, Pieter +7 more
We present the first results from the Faint Infra-Red Extragalactic Survey of the Hubble Deep Field South (HDF-S). Using a combination of deep near-infrared (NIR) data obtained with the Infrared Spectrograph and Array Camera at the VLT and the WFPC2 Hubble Space Telescope data, we construct a K-band-selected sample which is 50% and 90% complete fo…
An Ultraviolet through Infrared Look at Star Formation and Super Star Clusters in Two Circumnuclear Starburst Rings
Filippenko, Alexei V.; Ho, Luis C.; Maoz, Dan +2 more
We present broadband (U, V, I, and H) and narrowband (Hα+[N II] and Paα) images of the circumnuclear starburst rings in two nearby spiral galaxies, NGC 1512 and NGC 5248, obtained with the WFPC2 and NICMOS cameras on HST. Combined with previously published ultraviolet (UV) HST images at 2300 Å, these data provide a particularly wide wavelength ran…
Hubble Space Telescope Images of Stephan's Quintet: Star Cluster Formation in a Compact Group Environment
Charlton, Jane C.; Whitmore, Bradley C.; Gallagher, Sarah C. +2 more
Analysis of Hubble Space Telescope Wide Field Planetary Camera 2 images of Stephan's Quintet, Hickson Compact Group 92, yielded 115 candidate star clusters (with V-I<1.5). Unlike in merger remnants, the cluster candidates in Stephan's Quintet are not clustered in the inner regions of the galaxies; they are spread over the debris and surrounding…
New Photometry for the Intermediate-Age Large Magellanic Cloud Globular Cluster NGC 2121 and the Nature of the LMC Age Gap
Rich, R. Michael; Shara, Michael M.; Zurek, David
We report new photometry for the cluster NGC 2121 in the Large Magellanic Cloud, which shows a prominent hydrogen core exhaustion gap at the turnoff and a descending subgiant branch reminiscent of Galactic open clusters. We achieve an excellent fit using the Girardi isochrones, finding an age of 3.2+/-0.5 Gyr, with [Fe/H]=-0.6+/-0.2. The isochrone…
M31 Globular Clusters in the Hubble Space Telescope Archive. I. Cluster Detection and Completeness
Huchra, John P.; Barmby, Pauline
Globular clusters at the distance of M31 have apparent angular sizes of a few arcseconds. While many M31 globular clusters have been detected and studied from ground-based images, the high spatial resolution of the Hubble Space Telescope (HST) allows much more robust detection and characterization of star cluster properties. We present the results…
The Nonstellar Infrared Continuum of Seyfert Galaxies
Simpson, Chris; Alonso-Herrero, Almudena; Quillen, Alice C. +2 more
JHKL'M (1-5 µm) imaging of a sample of Seyfert 2 galaxies is presented. We have performed an accurate estimate of the near-infrared nonstellar nuclear fluxes. We confirm that the near-infrared nuclear continuum between 1 and 2.2 µm of some Seyfert 2s is dominated by stellar emission, whereas the continuum emission at longer wavelengths…
Hubble Space Telescope WFPC2 Imaging of Cassiopeia A
Chevalier, Roger A.; Borkowski, Kazimierz J.; van den Bergh, Sidney +4 more
The young galactic supernova remnant Cassiopeia A was imaged with Wide Field Planetary Camera 2 (WFPC2) aboard the Hubble Space Telescope through filters selected to capture the complete velocity range of the remnant's main shell in several emission lines. The primary lines detected, along with the specific WFPC2 filters used, were [O III] λλ4959,…
Speckle Interferometry of New and Problem Hipparcos Binaries. II. Observations Obtained in 1998-1999 from McDonald Observatory
Mason, Brian D.; Hartkopf, William I.; Holdenried, Ellis R. +1 more
The Hipparcos satellite made measurements of over 9734 known double stars, 3406 new double stars, and 11,687 unresolved but possible double stars. The high angular resolution afforded by speckle interferometry makes it an efficient means to confirm these systems from the ground, which were first discovered from space. Because of its coverage of a …