Search Publications
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…
Further Evidence for Large Central Mass-to-light Ratios in Early-type Galaxies: The Case of Ellipticals and Lenticulars in the A262 Cluster
Saglia, R. P.; Thomas, J.; Bender, R. +3 more
We present new radially resolved spectroscopy of eight early-type galaxies in the A262 cluster. The measurements include stellar rotation, velocity dispersion, H 3 and H 4 coefficients of the line-of-sight velocity distribution along the major and minor axes and an intermediate axis as well as line-strength index profiles of …
Water Ice in the Kuiper Belt
Brown, M. E.; Schaller, E. L.; Fraser, W. C.
We examine a large collection of low-resolution near-infrared spectra of Kuiper Belt objects (KBOs) and centaurs in an attempt to understand the presence of water ice in the Kuiper Belt. We find that water ice on the surface of these objects occurs in three separate manners: (1) Haumea family members uniquely show surfaces of nearly pure water ice…
Speckle Interferometry and Orbits of "Fast" Visual Binaries
Tokovinin, Andrei
Results of speckle observations at the 4.1 m SOAR telescope in 2012 (158 measures of 121 systems, 27 non-resolutions) are reported. The aim is to follow fast orbital motion of recently discovered or neglected close binaries and sub-systems. Here, eight previously known orbits are defined better, two more are completely revised, and five orbits are…
The Stellar and Gas Kinematics of the LITTLE THINGS Dwarf Irregular Galaxy NGC 1569
Brinks, Elias; Hunter, Deidre A.; Johnson, Megan +5 more
In order to understand the formation and evolution of Magellanic-type dwarf irregular (dIm) galaxies, one needs to understand their three-dimensional structure. We present measurements of the stellar velocity dispersion in NGC 1569, a nearby post-starburst dIm galaxy. The stellar vertical velocity dispersion, σz, coupled with the maximu…
PAndromeda—First Results from the High-cadence Monitoring of M31 with Pan-STARRS 1
Price, P. A.; Saglia, R. P.; Chambers, K. C. +19 more
The Pan-STARRS 1 (PS1) survey of M31 (PAndromeda) is designed to identify gravitational microlensing events, caused by bulge and disk stars (self-lensing) and by compact matter in the halos of M31 and the Milky Way (halo lensing or lensing by massive compact halo objects). With the 7 deg2 field of view (FOV) of PS1, the entire disk of M…
AKARI Infrared Camera Survey of the Large Magellanic Cloud. I. Point-source Catalog
Onaka, Takashi; Tanabé, Toshihiko; Ita, Yoshifusa +10 more
We present a near- to mid-infrared point-source catalog of five photometric bands at 3.2, 7, 11, 15, and 24 µm for a 10 deg2 area of the Large Magellanic Cloud (LMC) obtained with the Infrared Camera on board the AKARI satellite. To cover the survey area the observations were carried out at three separate seasons from 2006 May to …
An Inverse Compton Scattering Origin of X-Ray Flares from Sgr A*
Genzel, R.; Heinke, C. O.; Grosso, N. +6 more
The X-ray and near-IR emission from Sgr A* is dominated by flaring, while a quiescent component dominates the emission at radio and submillimeter (sub-mm) wavelengths. The spectral energy distribution of the quiescent emission from Sgr A* peaks at sub-mm wavelengths and is modeled as synchrotron radiation from a thermal population of electrons in …
A Treasury Study of Star-forming Regions in the Local Group. I. HST Photometry of Young Populations in Six Dwarf Galaxies
Massey, Philip; Bianchi, Luciana; Olsen, K. A. G. +2 more
We present a comprehensive study of young stellar populations in six dwarf galaxies in or near the Local Group: Phoenix, Pegasus, Sextans A, Sextans B, WLM, and NGC 6822. Their star-forming regions, selected from GALEX wide-field far-UV imaging, were imaged (at sub-pc resolution) with the WFPC2 camera on board the Hubble Space Telescope (HST) in s…
HST/COS Observations of Thirteen New He II Quasars
Anderson, Scott F.; Schneider, Donald P.; York, Donald G. +3 more
The full reionization of intergalactic helium was a major event in the history of the intergalactic medium (IGM), and UV observations of the He II Gunn-Peterson trough allow us to characterize the end of this process at z ~ 3. Due to intervening hydrogen absorption, quasars allowing such study are rare, with only 33 known in the literature, and mo…