Search Publications
Observations of a Z = 1.44 Dusty, Ultraluminous Galaxy and Implications for Deep Submillimeter Surveys
Smail, Ian; Graham, James R.; Dey, Arjun +3 more
We present new near-infrared and optical spectroscopic observations that confirm the redshift of the z=1.44 extremely red object ERO J164502+4626.4 (object 10 of Hu & Ridgway, formerly known as HR 10 or [HR94] 10) and a Hubble Space Telescope image that reveals a reflected S-shaped morphology at (rest-frame) near-ultraviolet wavelengths. The c…
Using HUBBLE SPACE TELESCOPE Imaging of Nuclear Dust Morphology to Rule Out Bars Fueling Seyfert Nuclei
Mulchaey, John S.; Regan, Michael W.
If active galactic nuclei (AGN) are powered by the accretion of matter onto massive black holes, how does the gas in the host galaxy lose the required angular momentum to approach the black hole? Gas easily transfers angular momentum to stars in strong bars, making them likely candidates. Although ground-based searches for bars in active galaxies …
The Hα Luminosity Function and Global Star Formation Rate from Redshifts of 1-2
Teplitz, Harry I.; McCarthy, Patrick J.; Malumuth, Eliot M. +4 more
We present a luminosity function for Hα emission from galaxies at redshifts between 0.7 and 1.9 based on slitless spectroscopy with the near-infrared camera and multiobject spectrometer on the Hubble Space Telescope. The luminosity function is well fit by a Schechter function over the range 6×1041<L(Hα)<2×1043 ergs s
The Diffuse Interstellar Clouds toward 23 Orionis
York, Donald G.; Lauroesch, James T.; Welty, Daniel E. +3 more
Spectra obtained with the Hubble Space Telescope Goddard High Resolution Spectrograph are combined with high-resolution optical spectra and UV spectra from Copernicus to study the abundances and physical conditions in the diffuse interstellar clouds seen along the line of sight to the star 23 Ori. Multiple absorption components are present for eac…
Weak ice absorption features at 7.24 and 7.41 MU M in the spectrum of the obscured young stellar object W 33A
de Graauw, Th.; van Dishoeck, E. F.; Whittet, D. C. B. +7 more
ISO-SWS observations of the highly obscured young stellar object W 33A reveal two broad absorption features centered at 7.24 and 7.41 mu m. Comparison to interstellar ice analogs shows that the 7.24 mu m band can be well matched by the CH deformation mode of formic acid (HCOOH), while the 7.41 mu m band can be fitted both by the formate ion (HCOO(…
A comprehensive study of intense star formation bursts in irregular and compact galaxies
Mas-Hesse, J. Miguel; Kunth, Daniel
We have analyzed the properties of the star formation episodes taking place in a sample of blue compact and irregular galaxies by comparing their multiwavelength observational properties with the predictions of evolutionary population synthesis models. This method has allowed us to constrain the age, star formation regime (instantaneous or extende…
The Population of Weak Mg II Absorbers. I. A Survey of 26 QSO HIRES/Keck Spectra
Vogt, Steven S.; Charlton, Jane C.; Churchill, Christopher W. +1 more
We present a search for ``weak'' Mg II absorbers [those with Wr(2796)<0.3 Å] in the HIRES/Keck spectra of 26 QSOs. We found 30, of which 23 are newly discovered. The spectra are 80% complete to Wr(2796)=0.02 Å and have a cumulative redshift path of ~17.2 for the redshift range 0.4<=z<=1.4. The number of absorbers per…
White Dwarfs in Cataclysmic Variables
Sion, E. M.
Prior to the last 15 years, the literature on cataclysmic variables (CVs) contained little on the properties of the underlying white dwarf accreter other than estimates of their masses. They were regarded simply as nondescript potential wells for studies of accretion disk structure and stability. Estimates of their masses and associated core compo…
Signatures of the Youngest Starbursts: Optically Thick Thermal Bremsstrahlung Radio Sources in Henize 2-10
Kobulnicky, Henry A.; Johnson, Kelsey E.
VLA radio continuum imaging reveals compact (<8 pc)~1 mJy radio sources in the central 5" starburst region of the blue compact galaxy Henize 2-10. While the global radio continuum spectrum is a power law (Sν~να) indicative of nonthermal processes (α~=-0.5), the radio sources have positive (α>0.0) spectral indices sugges…
A Keck High-Resolution Spectroscopic Study of the Orion Nebula Proplyds
O'Dell, C. R.; Henney, W. J.
We present the results of spectroscopy of four bright proplyds in the Orion Nebula obtained at a velocity resolution of 6 km s-1. After careful isolation of the proplyd spectra from the confusing nebular radiation, the emission-line profiles are compared with those predicted by realistic dynamic/photoionization models of the objects. Th…