Search Publications
The Evolution of the Global Stellar Mass Density at 0<z<3
Papovich, Casey; Dickinson, Mark; Ferguson, Henry C. +1 more
The buildup of stellar mass in galaxies is the consequence of their past star formation and merging histories. Here we report measurements of rest-frame optical light and calculations of stellar mass at high redshift based on an infrared-selected sample of galaxies from the Hubble Deep Field-North. The bright envelope of rest-frame B-band galaxy l…
Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 Parsecs: The Northern Sample. I.
Gray, R. O.; Corbally, C. J.; Garrison, R. F. +2 more
We have embarked on a project, under the aegis of the Nearby Stars (NStars)/Space Interferometry Mission Preparatory Science Program, to obtain spectra, spectral types, and, where feasible, basic physical parameters for the 3600 dwarf and giant stars earlier than M0 within 40 pc of the Sun. In this paper, we report on the results of this project f…
Age and metallicity distribution of the Galactic bulge from extensive optical and near-IR stellar photometry
Rejkuba, M.; Greggio, L.; Zoccali, M. +7 more
We present a new determination of the metallicity distribution, age, and luminosity function of the Galactic bulge stellar population. By combining near-IR data from the 2MASS survey, from the SOFI imager at ESO NTT and the NICMOS camera on board HST we were able to construct color-magnitude diagrams (CMD) and luminosity functions (LF) with large …
A high-velocity ionized outflow and XUV photosphere in the narrow emission line quasar PG1211+143
O'Brien, P. T.; King, A. R.; Reeves, J. N. +3 more
We report on the analysis of a ~60-ks XMM-Newton observation of the bright, narrow emission line quasar PG1211+143. Absorption lines are seen in both European Photon Imaging Camera and Reflection Grating Spectrometer spectra corresponding to H- and He-like ions of Fe, S, Mg, Ne, O, N and C. The observed line energies indicate an ionized outflow ve…
JEM-X: The X-ray monitor aboard INTEGRAL
Andersson, H.; Frontera, F.; Costa, E. +52 more
The JEM-X monitor provides X-ray spectra and imaging with arcminute angular resolution in the 3 to 35 keV band. The good angular resolution and the low energy response of JEM-X plays an important role in the identification of gamma ray sources and in the analysis and scientific interpretation of the combined X-ray and gamma ray data. JEM-X is a co…
Axisymmetric Dynamical Models of the Central Regions of Galaxies
Filippenko, Alexei V.; Ho, Luis C.; Gebhardt, Karl +12 more
We present axisymmetric, orbit superposition models for 12 galaxies using data taken with the Hubble Space Telescope (HST) and ground-based observatories. In each galaxy, we detect a central black hole (BH) and measure its mass to accuracies ranging from 10% to 70%. We demonstrate that in most cases the BH detection requires both the HST and groun…
Binarity in Brown Dwarfs: T Dwarf Binaries Discovered with the Hubble Space Telescope Wide Field Planetary Camera 2
Kirkpatrick, J. Davy; Burgasser, Adam J.; Brown, Michael E. +3 more
We present the discovery of two T dwarf binaries, 2MASS 1225-2739AB and 2MASS 1534-2952AB, identified in a sample of 10 T dwarfs imaged with the Hubble Space Telescope (HST) Wide Field Planetary Camera 2. Companionship is established by the uniquely red F814W-F1042M colors of the binary components, caused by heavily pressure-broadened K I absorpti…
Cassini Imaging of Jupiter's Atmosphere, Satellites, and Rings
Dones, Luke; West, Robert A.; Porco, Carolyn C. +21 more
The Cassini Imaging Science Subsystem acquired about 26,000 images of the Jupiter system as the spacecraft encountered the giant planet en route to Saturn. We report findings on Jupiter's zonal winds, convective storms, low-latitude upper troposphere, polar stratosphere, and northern aurora. We also describe previously unseen emissions arising fro…
XMM-Newton Observations of the Perseus Cluster. I. The Temperature and Surface Brightness Structure
Böhringer, H.; Churazov, E.; Forman, W. +1 more
We present preliminary results of a XMM-Newton 50 ks observation of the Perseus Cluster that provides an unprecedented view of the central 0.5 Mpc region. The projected gas temperature declines smoothly by a factor of 2 from a maximum value of ~ 7 keV in the outer regions to just above 3 keV at the cluster center. Over this same range, the heavy-e…
Spatio-temporal structure of storm-time chorus
Gurnett, D. A.; Pickett, J. S.; Parrot, M. +2 more
We discuss chorus emissions measured by the four Cluster spacecraft at close separations during a geomagnetically disturbed period on 18 April 2002. We analyze the lower band of chorus below one half of the electron cyclotron frequency, measured at a radial distance of 4.4 Earth's radii, within a 2000 km long source region located close to the equ…