Search Publications
A HIPPARCOS Census of the Nearby OB Associations
Brown, A. G. A.; de Bruijne, J. H. J.; de Zeeuw, P. T. +2 more
A comprehensive census of the stellar content of the OB associations within 1 kpc from the Sun is presented, based on Hipparcos positions, proper motions, and parallaxes. It is a key part of a long-term project to study the formation, structure, and evolution of nearby young stellar groups and related star-forming regions. OB associations are unbo…
The Luminosity Function of Young Star Clusters in ``the Antennae'' Galaxies (NGC 4038-4039)
Leitherer, Claus; Whitmore, Bradley C.; Fall, S. Michael +3 more
The Wide Field Planetary Camera 2 of the Hubble Space Telescope has been used to obtain high-resolution images of NGC 4038/4039 that go roughly 3 mag deeper in V than previous observations made during cycle 2. These new images allow us to measure the luminosity functions (LFs) of clusters and stars over a range of 8 mag (-14<M_V<-6). To firs…
Spectral Irradiance Calibration in the Infrared. X. A Self-Consistent Radiometric All-Sky Network of Absolutely Calibrated Stellar Spectra
Noguchi, Kunio; Cohen, Martin; Walker, Russell G. +3 more
We start from our six absolutely calibrated continuous stellar spectra from 1.2 to 35 µm for K0, K1.5, K3, K5, and M0 giants. These were constructed as far as possible from actual observed spectral fragments taken from the ground, the Kuiper Airborne Observatory, and the IRAS Low Resolution Spectrometer, and all have a common calibration ped…
A Large Mid-Infrared Spectroscopic and Near-Infrared Imaging Survey of Ultraluminous Infrared Galaxies: Their Nature and Evolution
Lutz, D.; Genzel, R.; Rigopoulou, D. +3 more
We present a low-resolution mid-infrared spectroscopic survey of an unbiased sample of 62 ultraluminous infrared galaxies (ULIRGs) (LIR>1012Lsolar, z<=0.3) using ISOPHOT-S on board the Infrared Space Observatory (ISO). For comparison, we also present ISOPHOT-S spectra for 23 active galactic nuclei (AGNs) and …
HUBBLE SPACE TELESCOPE/NICMOS Imaging of Disks and Envelopes around Very Young Stars
Brandner, Wolfgang; Stapelfeldt, Karl R.; Terebey, Susan +3 more
We present HST/NICMOS observations with ~0.1"~15 AU resolution of six young stellar objects in the Taurus star formation region. The targets of our survey are three Class I IRAS sources (IRAS 04016+2610, IRAS 04248+2612, and IRAS 04302+2247) and three low-luminosity stars (DG Tau B, Haro 6-5B, and CoKu Tau/1) associated with Herbig-Haro jets. The …
A Hubble Space Telescope Survey for Resolved Companions of Planetary Nebula Nuclei
Bond, Howard E.; Ciardullo, Robin; Fullton, Laura K. +3 more
We report the results of a Hubble Space Telescope ``snapshot'' survey aimed at finding resolved binary companions of the central stars of Galactic planetary nebulae (PNe). Using the the Wide Field and Planetary Camera and Wide Field Planetary Camera 2, we searched the fields of 113 PNe for stars whose close proximity to the central star suggests a…
Radii and Effective Temperatures for G, K, and M Giants and Supergiants
Kulkarni, S. R.; Palmer, D.; van Belle, G. T. +13 more
Interferometrically determined angular diameters obtained at the Palomar Testbed Interferometer (PTI) for 69 giant and supergiant stars are presented. Spectral types of the 59 giant stars generally lie between G6 and M6, although a B7 giant is included; the nine bright giants and supergiants have spectral types between F5 and M5. Comparison of the…
Globular Cluster Systems. I. V-I Color Distributions
Gebhardt, Karl; Kissler-Patig, Markus
We have compiled data for the globular cluster systems of 50 galaxies from the Hubble Space Telescope Wide Field Planetary Camera 2 archive, of which 43 are type S0 or earlier. In this paper, we present the data set and derive the V-I color distributions. We derive the first four moments of the color distributions, as well as a measure for their n…
The Star Formation History of the Local Group Dwarf Galaxy Leo I
Freedman, Wendy L.; Aparicio, Antonio; Gallart, Carme +2 more
We present a quantitative analysis of the star formation history (SFH) of the Local Group dSph galaxy Leo I, from the information in its Hubble Space Telescope [(V-I),I] color-magnitude diagram (CMD). It reaches the level of the oldest main-sequence turnoffs, and this allows us to retrieve the SFH in considerable detail. The method we use is based…
The Formation and Evolution of Candidate Young Globular Clusters in NGC 3256
Zepf, Stephen E.; Freeman, Kenneth C.; Sharples, Ray M. +2 more
We present images of the recent galaxy merger NGC 3256 obtained with the Wide Field Planetary Camera 2 of the Hubble Space Telescope in B and I filters. We show that there is a large population of more than 1000 compact, bright, blue objects in this galaxy within the 7 kpcx7 kpc region studied. These objects have sizes, colors, and luminosities li…