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The Mass of the Candidate Exoplanet Companion to HD 33636 from Hubble Space Telescope Astrometry and High-Precision Radial Velocities
DOI: 10.1086/519956 Bibcode: 2007AJ....134..749B

Bizyaev, Dmitry; Smith, Verne V.; Harrison, Thomas E. +4 more

We have determined a dynamical mass for the companion to HD 33636 that indicates it is a low-mass star instead of an exoplanet. Our result is based on an analysis of Hubble Space Telescope (HST) astrometry and ground-based radial velocity data. We have obtained high-cadence radial velocity measurements spanning 1.3 yr of HD 33636 with the Hobby-Eb…

2007 The Astronomical Journal
Hipparcos eHST 64
Spectral Properties from Lyα to Hα for an Essentially Complete Sample of Quasars. I. Data
DOI: 10.1086/518505 Bibcode: 2007AJ....134..294S

Wills, D.; Shang, Zhaohui; Brotherton, Michael S. +1 more

We have obtained quasi-simultaneous ultraviolet-optical spectra for 22 out of 23 quasars in the complete Palomar-Green X-ray sample with redshift z<0.4 and MB<-23. The spectra cover rest-frame wavelengths from at least Lyα to Hα. Here we provide a detailed description of the data, including careful spectrophotometry and redshift d…

2007 The Astronomical Journal
eHST 64
A View of the M81 Galaxy Group via the Hα Window
DOI: 10.1086/512127 Bibcode: 2007AJ....133.1883K

Karachentsev, Igor D.; Kaisin, Serafim S.

We present images for 36 galaxies of the M81 Group obtained in the Hα line. Estimates of the Hα flux and star formation rate (SFR) are now available for all the known members of the group with absolute magnitudes down to MB=-10 mag. The character of distribution of the galaxies over three parameters, MB, SFR, and total hydrog…

2007 The Astronomical Journal
eHST 62
An Atlas of the Circumnuclear Regions of 75 Seyfert Galaxies in the Near-Ultraviolet with the Hubble Space Telescope Advanced Camera for Surveys
DOI: 10.1086/519448 Bibcode: 2007AJ....134..648M

Leitherer, Claus; Storchi-Bergmann, Thaisa; Pérez, Enrique +5 more

We present an atlas of the central regions of 75 Seyfert galaxies imaged in the near-UV with the Advanced Camera for Surveys of the Hubble Space Telescope at an average resolution of ~10 pc. These data complement archival high-resolution data from the Hubble Space Telescope at optical and near-IR wavelengths, creating an extremely valuable data se…

2007 The Astronomical Journal
eHST 61
The Stellar Populations in the Outer Regions of M33. III. Star Formation History
DOI: 10.1086/511186 Bibcode: 2007AJ....133.1138B

Sarajedini, Ata; Schommer, Robert; Geisler, Doug +2 more

We present a detailed analysis of the star formation history (SFH) of three fields in M33 located approximately four to six visual scale lengths from its nucleus. These fields were imaged with the Advanced Camera for Surveys on the Hubble Space Telescope and reach ~2.5 mag below the red clump of core helium-burning stars. The observed color-magnit…

2007 The Astronomical Journal
eHST 55
Bayesian Single-Epoch Photometric Classification of Supernovae
DOI: 10.1086/520956 Bibcode: 2007AJ....134.1285P

Maoz, Dan; Gal-Yam, Avishay; Poznanski, Dovi

Ongoing supernova (SN) surveys find hundreds of candidates that require confirmation for their various uses. Traditional classification based on follow-up spectroscopy of all candidates is virtually impossible for these large samples. The use of Type Ia SNe as standard candles is at an evolved stage that requires pure, uncontaminated samples. Howe…

2007 The Astronomical Journal
eHST 55
A Statistical Study of Accretion Disk Model Spectra for Cataclysmic Variables
DOI: 10.1086/522112 Bibcode: 2007AJ....134.1923P

Hubeny, Ivan; Puebla, Raúl E.; Diaz, Marcos P.

We have performed a statistical test of the currently used accretion disk models for cataclysmic variables (CVs) using a set of 33 CVs with steady disks (10 old novae and 23 nova-like systems). The mass transfer rate () for each system was also calculated. Ultraviolet (UV) data were fitted by model spectra using a multiparametric optimization meth…

2007 The Astronomical Journal
IUE eHST 53
XMM-Newton and Chandra Spectroscopy of the Variable High-Energy Absorption of PG 1115+080: Refined Outflow Constraints
DOI: 10.1086/512364 Bibcode: 2007AJ....133.1849C

Brandt, W. N.; Chartas, G.; Gallagher, S. C. +1 more

We present results from multi-epoch spectral analysis of XMM-Newton and Chandra observations of the mini-broad absorption line (BAL) quasar PG 1115+080. This is one of the few X-ray-detected mini-BAL quasars to date that is bright enough in the X-ray band, mostly due to large gravitational-lensing magnifications, to allow in-depth spectral analysi…

2007 The Astronomical Journal
XMM-Newton 52
Stellar Populations of Globular Clusters in the Elliptical Galaxy NGC 1407
DOI: 10.1086/518504 Bibcode: 2007AJ....134..391C

Forbes, Duncan A.; Brodie, Jean P.; Beasley, Michael A. +2 more

We present high-quality Keck spectroscopic data for a sample of 20 globular clusters (GCs) in the massive E0 galaxy NGC 1407. A subset of 20 line-strength indices of the Lick/IDS system has been measured for both the GC system and the central integrated starlight of the galaxy. Ages, metallicities, and [α/Fe] ratios have been derived using several…

2007 The Astronomical Journal
eHST 51
Global Properties of the Globular Cluster Systems of Four Spiral Galaxies
DOI: 10.1086/521397 Bibcode: 2007AJ....134.1403R

Kundu, Arunav; Zepf, Stephen E.; Rhode, Katherine L. +1 more

We present results from a wide-field imaging study of the globular cluster (GC) systems of a sample of edge-on, Sb-Sc spiral galaxies ~7-20 Mpc away. This study is part of a larger survey of the ensemble properties of the GC populations of giant galaxies. We imaged the galaxies in BVR filters with large-format CCD detectors on the WIYN 3.5 m teles…

2007 The Astronomical Journal
eHST 49