Search Publications
Extragalactic Source Counts at 24 Microns in the Spitzer First Look Survey
Im, M.; Frayer, D. T.; Helou, G. +18 more
We present the Spitzer Multiband Imaging Photometer 24 µm source counts in the Extragalactic First Look Survey (FLS) main, verification, and European Large Area ISO Survey N1 fields. Spitzer's increased sensitivity and efficiency in large areal coverage over previous infrared telescopes, coupled with the enhanced sensitivity of the 24 µ…
Intrinsic Absorption in the Spectrum of Markarian 279: Simultaneous Chandra, FUSE, and STIS Observations
Kaiser, Mary Elizabeth; Green, Richard F.; Scott, Jennifer E. +12 more
We present a study of the intrinsic X-ray and far-ultraviolet absorption in the Seyfert 1.5 galaxy Markarian 279 using simultaneous observations from the Chandra X-ray Observatory, the Space Telescope Imaging Spectrograph aboard the Hubble Space Telescope, and the Far Ultraviolet Spectroscopic Explorer (FUSE). We also present FUSE observations mad…
Principles of Seismic Holography for Diagnostics of the Shallow Subphotosphere
Braun, D. C.; Lindsey, Charles
We develop the wave-mechanical formalism for phase-correlation computational seismic holography of the shallow subphotosphere under the plane-parallel approximation and apply it to helioseismic Doppler observations from the Michelson Doppler Imager on the SOHO spacecraft of both the quiet Sun and active regions. We compare holographic signatures c…
Emission Line Properties of Active Galactic Nuclei from a Post-COSTAR Hubble Space Telescope Faint Object Spectrograph Spectral Atlas
Green, Paul J.; Vestergaard, Marianne; Aldcroft, Tom L. +4 more
We present consistent emission-line measurements for active galactic nuclei (AGNs), useful for reliable statistical studies of emission line properties. This paper joins a series including similar measurements of 993 spectra from the Large Bright Quasar Survey and 174 spectra of AGNs obtained from the Faint Object Spectrograph (FOS) on the Hubble …
A Multiwavelength Perspective of Flares on HR 1099: 4 Years of Coordinated Campaigns
Ayres, Thomas R.; Brown, Alexander; Skinner, Stephen L. +7 more
We report on four years of multiple wavelength observations of the RS CVn system V711 Tau (HR 1099) from 1993, 1994, 1996, and 1998. This combination of radio, ultraviolet, extreme ultraviolet, and X-ray observations allows us to view, in the most comprehensive manner currently possible, the coronal and upper atmospheric variability of this active…
The Nature of Luminous X-Ray Sources with Mid-Infrared Counterparts
Le Floc'h, E.; Barmby, P.; Dole, H. +28 more
We investigate the luminous X-ray sources in the Lockman Hole (LH) and the extended Groth strip (EGS) detected at 24 µm using the Multiband Imaging Photometer (MIPS) and also with the Infrared Array Camera (IRAC) on board the Spitzer Space Telescope. We assemble optical/infrared spectral energy distributions (SEDs) for 45 X-ray/24 µm s…
A Complete Atlas of Recalibrated Hubble Space Telescope Faint Object Spectrograph Spectra of Active Galactic Nuclei and Quasars. I. Pre-COSTAR Spectra
Koratkar, Anuradha P.; Evans, Ian N.
We have recalibrated all nonpolarimetric, pre-COSTAR, archival Hubble Space Telescope Faint Object Spectrograph UV and optical spectrophotometry of active galaxies and quasars in order to extract uniformly calibrated spectrophotometric data for further detailed scientific investigations. The raw archival spectra have been recalibrated using the la…
Heavy Element Abundances in Late-B and Early-A Stars. I. Co-Added IUE Spectra of HgMn Stars
Leckrone, D. S.; Wahlgren, G. M.; Adelman, S. J. +2 more
Very heavy elements (Pt, Au, Hg, Tl, and Bi) are found to be enhanced in the atmospheres of the chemically peculiar stars of the upper main sequence by up to a million times the solar system levels. Such enhancements are believed to result from atmospheric dynamics (i.e., diffusion) rather than scenarios that dredge up nuclear-processed material t…
An Atlas of Far-Ultraviolet Spectra of Wolf-Rayet Stars from the FUSE Satellite
Walborn, Nolan R.; Sonneborn, George; Hutchings, John B. +5 more
We present an atlas of far-ultraviolet spectra of 21 Wolf-Rayet (WR) stars in the Galaxy and Large and Small Magellanic Clouds, secured with the Far Ultraviolet Spectroscopic Explorer (FUSE) satellite. The data cover the wavelength range of 912-1190 Å at a spectral resolution of 0.1 Å and span examples of most subtypes in the WN and WC sequences. …
Spectral Classification of Stars in A Supplement to the Bright Star Catalogue
Abt, Helmut A.
MK spectral types are given for about 584 stars in A Supplement to the Bright Star Catalogue. These are compared with Hipparcos parallaxes to check the reliability of those classifications. The estimated errors are +/-1.2 subtypes, and 10% of the luminosity classes may be wrong.