Search Publications
The Three-body System δ Circini
Mayer, Pavel; Harmanec, Petr; Sana, Hugues +1 more
Delta Cir is known as an O7.5 III eclipsing and spectroscopic binary with an eccentric orbit. Penny et al. discovered the presence of a third component in the IUE spectra. The eclipsing binary and the third body revolve around a common center of gravity with a period of 1644 days in an eccentric orbit with a semimajor axis of 10 AU. We demonstrate…
Measuring Metallicities with Hubble Space Telescope/Wide-Field Camera 3 Photometry
Bond, Howard E.; Anthony-Twarog, Barbara J.; Holtzman, Jon A. +4 more
We quantified and calibrated the metallicity and temperature sensitivities of colors derived from nine Wide-Field Camera 3 filters on board the Hubble Space Telescope using Dartmouth isochrones and Kurucz atmosphere models. The theoretical isochrone colors were tested and calibrated against observations of five well studied galactic clusters, M92,…
A Magnified View of Star Formation at z = 0.9 From Two Lensed Galaxies
Veilleux, Sylvain; Rigby, Jane R.; Swinbank, Mark +1 more
We present new narrowband Hα imaging from the Hubble Space Telescope of two z = 0.91 galaxies that have been lensed by the foreground galaxy cluster A2390. These data probe spatial scales as small as ~0.3 kpc, providing a magnified look at the morphology of star formation at an epoch when the global star formation rate (SFR) was high. However, dus…
First Ultraviolet Reflectance Measurements of Several Kuiper Belt Objects, Kuiper Belt Object Satellites, and New Ultraviolet Measurements of a Centaur
Stern, S. A.; Schindhelm, R.; Cunningham, N. J.
We observed the 2600-3200 Å (hereafter, mid-UV) reflectance of two Kuiper Belt Objects (KBOs), two KBO satellites, and a Centaur, using the Hubble Space Telescope (HST) Cosmic Origins Spectrograph (COS). Other than measurements of the Pluto system, these constitute the first UV measurements obtained of KBOs, and KBO satellites, and new HST UV meas…
The Massive Star Population in M101. II. Spatial Variations in the Recent Star Formation History
Humphreys, Roberta M.; Grammer, Skyler
We investigate star formation history (SFH) as a function of radius in M101 using archival Hubble Space Telescope Advanced Camera for Surveys photometry. We derive the SFH from the resolved stellar populations in five 2' wide annuli. Binning the SFH into time frames corresponding to stellar populations traced by Hα, far-ultraviolet, and near-ultra…
Updated Models for the Creation of a Low-Z Qso Absorber By a Dwarf Galaxy Wind
Danforth, Charles W.; Stocke, John T.; Keeney, Brian A. +2 more
We present new GALEX images and optical spectroscopy of J1229+02, a dwarf post-starburst galaxy located 81 kpc from the 1585 km {{s}-1} absorber in the 3C 273 sight line. The absence of Hα emission and the faint GALEX UV fluxes confirm that the galaxy's recent star formation rate is \lt {{10}-3} {{M}⊙ } y{{r}-…
The Baryon Oscillation Spectroscopic Survey of SDSS-III
Weiner, Benjamin J.; Finley, Hayley; Brandt, W. N. +162 more
The Baryon Oscillation Spectroscopic Survey (BOSS) is designed to measure the scale of baryon acoustic oscillations (BAO) in the clustering of matter over a larger volume than the combined efforts of all previous spectroscopic surveys of large-scale structure. BOSS uses 1.5 million luminous galaxies as faint as i = 19.9 over 10,000 deg2…
The Fourth US Naval Observatory CCD Astrograph Catalog (UCAC4)
Zacharias, N.; Finch, C. T.; Girard, T. M. +4 more
The fourth United States Naval Observatory (USNO) CCD Astrograph Catalog, UCAC4, was released in 2012 August (double-sided DVD and CDS data center Vizier catalog I/322). It is the final release in this series and contains over 113 million objects; over 105 million of them with proper motions (PMs). UCAC4 is an updated version of UCAC3 with about t…
Cosmicflows-2: The Data
Dolphin, Andrew E.; Wu, Po-Feng; Shaya, Edward J. +11 more
Cosmicflows-2 is a compilation of distances and peculiar velocities for over 8000 galaxies. Numerically the largest contributions come from the luminosity-line width correlation for spirals, the Tully-Fisher relation (TFR), and the related fundamental plane relation for E/S0 systems, but over 1000 distances are contributed by methods that provide …
Confirmation of Faint Dwarf Galaxies in the M81 Group
Chiboucas, Kristin; Tully, R. Brent; Karachentsev, Igor D. +1 more
We have followed up on the results of a 65 deg2 CFHT/MegaCam imaging survey of the nearby M81 Group searching for faint and ultra-faint dwarf galaxies. The original survey turned up 22 faint candidate dwarf members. Based on two-color HST ACS/WFC and WFPC2 photometry, we now confirm 14 of these as dwarf galaxy members of the group. Dist…