Search Publications
Uncloaking Globular Clusters in the Inner Galaxy
Minniti, Dante; Mateo, Mario; von Braun, Kaspar +4 more
Extensive photometric studies of the globular clusters located toward the center of the Milky Way have been historically neglected. The presence of patchy differential reddening in front of these clusters has proven to be a significant obstacle to their detailed study. We present here a well defined and reasonably homogeneous photometric database …
The Solar Neighborhood. XXVIII. The Multiplicity Fraction of Nearby Stars from 5 to 70 AU and the Brown Dwarf Desert around M Dwarfs
Krist, John E.; Golimowski, David A.; Henry, Todd J. +2 more
We report on our analysis of Hubble Space Telescope/NICMOS snapshot high-resolution images of 255 stars in 201 systems within ~10 pc of the Sun. Photometry was obtained through filters F110W, F180M, F207M, and F222M using NICMOS Camera 2. These filters were selected to permit clear identification of cool brown dwarfs through methane contrast imagi…
The History and Environment of a Faded Quasar: Hubble Space Telescope Observations of Hanny's Voorwerp and IC 2497
Schawinski, Kevin; Keel, William C.; Thomas, Daniel +6 more
We present Hubble Space Telescope imaging and spectroscopy, along with supporting Galaxy Evolution Explorer and ground-based data, for the extended high-ionization cloud known as Hanny's Voorwerp, near the spiral galaxy IC 2497. Wide Field Camera 3 images show complex dust absorption near the nucleus of IC 2497. The galaxy core in these data is, w…
Observations of Binary Stars with the Differential Speckle Survey Instrument. IV. Observations of Kepler, CoRoT, and Hipparcos Stars from the Gemini North Telescope
Howell, Steve B.; Ciardi, David R.; Everett, Mark E. +1 more
We present the results of 71 speckle observations of binary and unresolved stars, most of which were observed with the DSSI speckle camera at the Gemini North Telescope in 2012 July. The main purpose of the run was to obtain diffraction-limited images of high-priority targets for the Kepler and CoRoT missions, but in addition, we observed a number…
Hubble Space Telescope Observations of an Outer Field in Omega Centauri: A Definitive Helium Abundance
Anderson, J.; Milone, A. P.; Bedin, L. R. +6 more
We revisit the problem of the split main sequence (MS) of the globular cluster ω Centauri, and report the results of two-epoch Hubble Space Telescope observations of an outer field, for which proper motions give us a pure sample of cluster members, and an improved separation of the two branches of the MS. Using a new set of stellar models covering…
The Nuclear Infrared Emission of Low-luminosity Active Galactic Nuclei
Colina, L.; Aretxaga, I.; Packham, C. +9 more
We present high-resolution mid-infrared (MIR) imaging, nuclear spectral energy distributions (SEDs), and archival Spitzer spectra for 22 low-luminosity active galactic nuclei (LLAGNs; L bol <~ 1042 erg s-1). Infrared (IR) observations may advance our understanding of the accretion flows in LLAGNs, the fate of th…
Investigation of Dual Active Nuclei, Outflows, Shock-heated Gas, and Young Star Clusters in Markarian 266
Sturm, E.; Veilleux, S.; Sanders, D. B. +24 more
Results of observations with the Spitzer, Hubble, GALEX, Chandra, and XMM-Newton space telescopes are presented for the luminous infrared galaxy (LIRG) merger Markarian 266. The SW (Seyfert 2) and NE (LINER) nuclei reside in galaxies with Hubble types SBb (pec) and S0/a (pec), respectively. Both companions are more luminous than L* galaxies and th…
Mean-flux-regulated Principal Component Analysis Continuum Fitting of Sloan Digital Sky Survey Lyα Forest Spectra
Spergel, David N.; Suzuki, Nao; Lee, Khee-Gan
Continuum fitting is an important aspect of Lyα forest science, since errors in the derived optical depths scale with the fractional continuum error. However, traditional methods of estimating continua in noisy and moderate-resolution spectra (e.g., Sloan Digital Sky Survey, SDSS; S/N <~ 10 pixel-1 and R ~ 2000), such as power-law ex…
The Spectral Energy Distributions and Infrared Luminosities of z ≈ 2 Dust-obscured Galaxies from Herschel and Spitzer
Dey, Arjun; Bussmann, R. S.; Alberts, Stacey +6 more
Dust-obscured galaxies (DOGs) are a subset of high-redshift (z ≈ 2) optically-faint ultra-luminous infrared galaxies (ULIRGs, e.g., L IR > 1012 L ⊙). We present new far-infrared photometry, at 250, 350, and 500 µm (observed-frame), from the Herschel Space Telescope for a large sample of 113 DOGs with spect…
Wide Companions to Hipparcos Stars within 67 pc of the Sun
Lépine, Sébastien; Tokovinin, Andrei
A catalog of common-proper-motion (CPM) companions to stars within 67 pc of the Sun is constructed based on the SUPERBLINK proper-motion survey. It contains 1392 CPM pairs with angular separations 30'' < ρ < 1800'', relative proper motion between the two components less than 25 mas yr-1, and magnitudes and colors of the secondarie…