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…
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…
Hubble Space Telescope Observations of the HD 202628 Debris Disk
Krist, John E.; Stapelfeldt, Karl R.; Plavchan, Peter +1 more
A ring-shaped debris disk around the G2V star HD 202628 (d = 24.4 pc) was imaged in scattered light at visible wavelengths using the coronagraphic mode of the Space Telescope Imaging Spectrograph on the Hubble Space Telescope. The ring is inclined by ~64° from face-on, based on the apparent major/minor axis ratio, with the major axis aligned along…
A Deep, Wide-field, and Panchromatic View of 47 Tuc and the SMC with HST: Observations and Data Analysis Methods
Anderson, Jay; Dotter, Aaron; Rich, R. M. +10 more
In Hubble Space Telescope (HST) Cycle 17, we imaged the well-known globular star cluster 47 Tucanae for 121 orbits using the Wide Field Channel of the Advanced Camera for Surveys (ACS) and both the UV/visible (UVIS) and IR channels of the newly installed Wide Field Camera 3 (WFC3) instrument (GO-11677, PI: H. Richer). This unique data set was obta…
The Spectral Energy Distributions of White Dwarfs in 47 Tucanae: The Distance to the Cluster
Anderson, J.; Tremblay, P. -E.; Stetson, P. B. +13 more
We present a new distance determination to the Galactic globular cluster 47 Tucanae by fitting the spectral energy distributions of its white dwarfs (WDs) to pure hydrogen atmosphere WD models. Our photometric data set is obtained from a 121-orbit Hubble Space Telescope program using the Wide Field Camera 3 UVIS/IR channels, capturing F390W, F606W…