355 citations · 4.5k across the 73 of their papers we have counts for
23 papers · 1 filter
The Anisotropic Spatial Distribution of Hypervelocity Stars
Warren R. Brown, Margaret J. Geller, Scott J. Kenyon +1
We study the distribution of angular positions and angular separations of unbound hypervelocity stars (HVSs). HVSs are spatially anisotropic at the 3-sigma level. The spatial aniso…
MMT Hypervelocity Star Survey
Warren R. Brown, Margaret J. Geller, Scott J. Kenyon
We describe a new survey for unbound hypervelocity stars (HVSs), stars traveling with such extreme velocities that dynamical ejection from a massive black hole (MBH) is their most…
Hypervelocity Stars: From the Galactic Center to the Halo
S. J. Kenyon, B. C. Bromley, M. J. Geller +1
Hypervelocity stars (HVS) traverse the Galaxy from the central black hole to the outer halo. We show that the Galactic potential within 200 pc acts as a high pass filter preventing…
The Century Survey Galactic Halo Project III: A Complete 4300 deg^2 Survey of Blue Horizontal Branch Stars in the Metal-Weak Thick Disk and Inner Halo
Warren R. Brown, Timothy C. Beers, Ronald Wilhelm +4
We present a complete spectroscopic survey of 2414 2MASS-selected blue horizontal branch (BHB) candidates selected over 4300 deg^2 of the sky. We identify 655 BHB stars in this non…
Hypervelocity Stars III. The Space Density and Ejection History of Main Sequence Stars from the Galactic Center
Warren R. Brown, Margaret J. Geller, Scott J. Kenyon +2
We report the discovery of 3 new unbound hypervelocity stars (HVSs), stars traveling with such extreme velocities that dynamical ejection from a massive black hole (MBH) is their o…
The Discovery of a Companion to the Lowest Mass White Dwarf
Mukremin Kilic, Warren R. Brown, Carlos Allende Prieto +2
We report the detection of a radial velocity companion to SDSS J091709.55+463821.8, the lowest mass white dwarf currently known with M~0.17Msun. The radial velocity of the white dw…
Hypervelocity Stars II. The Bound Population
Warren R. Brown, Margaret J. Geller, Scott J. Kenyon +2
Hypervelocity stars (HVSs) are stars ejected completely out of the Milky Way by three-body interactions with the massive black hole in the Galactic center. We describe 643 new spec…
SDSS 0809+1729: Connections Between Extremely Metal Poor Galaxies and Gamma Ray Burst Hosts
Lisa J. Kewley, Warren R. Brown, Margaret J. Geller +2
We discuss the serendipitous discovery of an extremely metal poor galaxy, SDSS 0809+1729, classified as a star in the Sloan Digital Sky Survey (SDSS). The galaxy has a redshift z =…
Infrared Properties of Close Pairs of Galaxies
Margaret J. Geller, Scott J. Kenyon, Elizabeth J. Barton +2
We discuss spectroscopy and infrared photometry for a complete sample of ~ 800 galaxies in close pairs objectively selected from the CfA2 redshift survey. We use 2MASS to compare n…
Hypervelocity Stars. I. The Spectroscopic Survey
Warren R. Brown, Margaret J. Geller, Scott J. Kenyon +1
We discuss our targeted search for hypervelocity stars (HVSs), stars traveling with velocities so extreme that dynamical ejection from a massive black hole is their only suggested…
Tidally Triggered Star Formation in Close Pairs of Galaxies: Major and Minor Interactions
Deborah Freedman Woods, Margaret J. Geller, Elizabeth J. Barton
We study star formation in a sample of 345 galaxies in 167 pairs and compact groups drawn from the original CfA2 Redshift Survey and from a follow-up search for companions. We cons…
The Century Survey Galactic Halo Project II: Global Properties and the Luminosity Function of Field Blue Horizontal Branch Stars
Warren R. Brown, Margaret J. Geller, Scott J. Kenyon +4
We discuss a 175 deg^2 spectroscopic survey for blue horizontal branch (BHB) stars in the Galactic halo. We use the Two Micron All Sky Survey (2MASS) and the Sloan Digital Sky Surv…
Surveying the Inner Halo of the Galaxy with 2MASS-Selected Horizontal Branch Candidates
Warren R. Brown, M. J. Geller, S. J. Kenyon +3
We use 2MASS photometry to select blue horizontal branch (BHB) candidates covering the sky |b|>15 deg. A 12.5<J<15.5 sample of BHB stars traces the thick disk and inner halo to d<9…
The Century Survey Galactic Halo Project I: Stellar Spectral Analysis
W. R. Brown, C. Allende Prieto, T. C. Beers +4
The Century Survey Galactic Halo Project is a photometric and spectroscopic survey from which we select relatively blue stars (V-R<0.30 mag) as probes of the Milky Way halo. The Su…
Tidally-Triggered Star Formation in Close Pairs of Galaxies 2: Constraints on Burst Strengths and Ages
Elizabeth Barton Gillespie, Margaret J. Geller, Scott J. Kenyon
Galaxy-galaxy interactions rearrange the baryons in galaxies and trigger substantial star formation; the aggregate effects of these interactions on the evolutionary histories of ga…
Correlated radial velocity and X-ray variations in HD 154791/4U 1700+24
D. K. Galloway, J. L. Sokoloski, S. J. Kenyon
We present evidence for approximately 400-d variations in the radial velocity of HD 154791 (V934 Her), the suggested optical counterpart of 4U 1700+24. The variations are correlate…
H-Band and Spectroscopic Properties of Abell 1644
Aaron W. Tustin, Margaret J. Geller, Scott J. Kenyon +1
We discuss H-band (1.65 micrometer) near-infrared photometry of the central 3x3h^{-2} Mpc^2 of Abell 1644 to a limiting M_H~M^*_H+3 (throughout this paper H_0=100 h km s^{-1} Mpc^{…
A Near-Infrared Imaging Survey of the Chamaeleon I Dark Cloud
M. Gomez, S. J. Kenyon
We describe a near-infrared imaging survey covering approximately 1 square deg of the Chamaeleon I dark cloud. The survey is complete for K < 15.0, H < 16.0, and J < 16.5, roughly…
The Tully-Fisher Relation as a Measure of Luminosity Evolution: A Low Redshift Baseline for Evolving Galaxies
Elizabeth J. Barton, Margaret J. Geller, Benjamin C. Bromley +2
We use optical rotation curves to investigate the R-band Tully-Fisher properties of a sample of 90 spiral galaxies in close pairs. The galaxies follow the Tully-Fisher relation rem…
UV excess galaxies: Wolf-Rayet galaxies
Warren R. Brown, Scott J. Kenyon, Margaret J. Geller +1
We discuss V and R band photometry for 67% of the Sullivan et al. 2000 SA57 ultraviolet-selected galaxy sample. In a sample of 176 UV-selected galaxies, Sullivan et al. 2000 find t…
An Optical Study of BG Geminorum: An Ellipsoidal Binary with an Unseen Primar Star
P. J. Benson, A. Dullighan, A. Bonanos +2
We describe optical photometric and spectroscopic observations of the bright variable BG Geminorum. Optical photometry shows a pronounced ellipsoidal variation of the K0 I secondar…
Tidally-Triggered Star Formation in Close Pairs of Galaxies
Elizabeth J. Barton, Margaret J. Geller, Scott J. Kenyon
We analyze new optical spectra of a sample of 502 galaxies in close pairs and n-tuples, separated by <= 50/h kpc. We extracted the sample objectively from the CfA2 redshift survey,…
Dust Extinction and Molecular Cloud Structure: L977
J. Alves, C. Lada, E. Lada +2
We report results of a near--infrared imaging survey of L977, a dark cloud in Cygnus seen in projection against the plane of the Milky Way. We use measurements of the near--infrare…