Search Publications
The Radial Velocity Experiment (RAVE): First Data Release
Gilmore, G.; Freeman, K. C.; Evans, N. W. +51 more
We present the first data release of the Radial Velocity Experiment (RAVE), an ambitious spectroscopic survey to measure radial velocities and stellar atmosphere parameters (temperature, metallicity, and surface gravity) of up to one million stars using the Six Degree Field multiobject spectrograph on the 1.2 m UK Schmidt Telescope of the Anglo-Au…
The Hubble Ultra Deep Field
Ferguson, Henry C.; Koekemoer, Anton M.; Lucas, Ray A. +12 more
This paper presents the Hubble Ultra Deep Field (HUDF), a 1 million s exposure of an 11 arcmin2 region in the southern sky with the Advanced Camera for Surveys on the Hubble Space Telescope using Director's Discretionary Time. The exposure time was divided among four filters, F435W (B435), F606W (V606), F775W (i
Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 pc-The Southern Sample
Gray, R. O.; Corbally, C. J.; Garrison, R. F. +5 more
We are obtaining spectra, spectral types, and basic physical parameters for the nearly 3600 dwarf and giant stars earlier than M0 in the Hipparcos catalog within 40 pc of the Sun. Here we report on results for 1676 stars in the southern hemisphere observed at Cerro Tololo Inter-American Observatory and Steward Observatory. These results include ne…
Calibration of Synthetic Photometry Using DA White Dwarfs
Holberg, J. B.; Bergeron, Pierre
We have calibrated four major ground-based photometric systems with respect to the Hubble Space Telescope (HST) absolute flux scale, which is defined by Vega and four fundamental DA white dwarfs. These photometric systems include the Johnson-Kron-Cousins UBVRI, the Strömgren uvby filters, the Two Micron All Sky Survey JHKs, and the Sloa…
The X-Ray-to-Optical Properties of Optically Selected Active Galaxies over Wide Luminosity and Redshift Ranges
Lehmer, B. D.; Alexander, D. M.; Brandt, W. N. +5 more
We present partial-correlation analyses that examine the strengths of the relationships between l2500Å, l2keV, αOX, and redshift for optically selected active galactic nuclei (AGNs). We extend the work of Strateva and coworkers, which analyzed optically selected AGNs from the Sloan Digital Sky Survey (SDSS), by including 52 m…
Galaxies in the Hubble Ultra Deep Field. I. Detection, Multiband Photometry, Photometric Redshifts, and Morphology
Coe, Dan; Ford, Holland; Benítez, Narciso +3 more
We present aperture-matched point-spread function (PSF)-corrected BVi'z'JH photometry and Bayesian photometric redshifts (BPZ) for objects detected in the Hubble Ultra Deep Field (UDF), 8042 of which are detected at the 10 σ level (e.g., i'<29.01 or z'<28.43). Most of our objects are defined identically to those in the …
A Survey of Local Group Galaxies Currently Forming Stars. I. UBVRI Photometry of Stars in M31 and M33
Smith, R. C.; Massey, Philip; Hodge, Paul W. +4 more
We present UBVRI photometry obtained from Mosaic images of M31 and M33 using the Kitt Peak National Observatory 4 m telescope. We describe our data reduction and automated photometry techniques in some detail, as we will shortly perform a similar analysis of other Local Group galaxies. The present study covered 2.2 deg2 along the major …
The Gravity Field of the Saturnian System from Satellite Observations and Spacecraft Tracking Data
Jacobson, R. A.; Owen, W. M., Jr.; Mackenzie, R. A. +11 more
We present values for the masses of Saturn and its major satellites, the zonal harmonics in the spherical harmonic expansion of Saturn's gravitational potential, and the orientation of the pole of Saturn. We determined these values using an extensive data set: satellite astrometry from Earth-based observatories and the Hubble Space Telescope; Eart…
Hubble Space Telescope STIS Spectra of Nuclear Star Clusters in Spiral Galaxies: Dependence of Age and Mass on Hubble Type
Böker, Torsten; Ho, Luis C.; Shields, Joseph C. +5 more
We study the nuclear star clusters (NCs) in spiral galaxies of various Hubble types using spectra obtained with the STIS on board the Hubble Space Telescope (HST). We observed the nuclear clusters in 40 galaxies, selected from two previous HST WFPC2 imaging surveys. At a spatial resolution of ~0.2" the spectra provide a better separation of cluste…
A Survey of Kiloparsec-Scale Radio Outflows in Radio-Quiet Active Galactic Nuclei
Baum, Stefi A.; O'Dea, Christopher P.; Gallimore, Jack F. +2 more
Seyfert galaxies commonly host compact jets spanning 10-100 pc scales, but larger structures are resolved out in long-baseline aperture synthesis surveys. Previous, targeted studies showed that kiloparsec-scale radio structures (KSRs) may be a common feature of Seyfert and LINER galaxies, and the origin of KSRs may be starbursts or active galactic…