Search Publications
Tracing the Mass Growth and Star Formation Rate Evolution of Massive Galaxies from z ~ 6 to z ~ 1 in the Hubble Ultra-Deep Field
Stiavelli, Massimo; Franx, Marijn; van Dokkum, Pieter +8 more
We present an analysis of an H 160-selected photometric catalog of galaxies in the Hubble Ultra-Deep Field, using imaging from the WFC3/IR camera on the Hubble Space Telescope in combination with archival ultraviolet, optical, and near-infrared imaging. Using these data, we measure the spectral energy distributions of ~1500 galaxies to …
SUZAKU Observation of the Black Hole Binary 4U 1630-47 in the Very High State
Done, Chris; Shirahata, Mai; Ueda, Yoshihiro +7 more
We report the results from an X-ray and near-infrared observation of the Galactic black hole binary 4U 1630-47 in the very high state (VHS), performed with Suzaku and the Infrared Survey Facility around the peak of the 2012 September-October outburst. The X-ray spectrum is approximated by a steep power law, with photon index of 3.2, identifying th…
Plasma Flows in the Heliosheath along the Voyager 1 and 2 Trajectories due to Effects of the 11 yr Solar Cycle
Toth, G.; Richardson, J. D.; Opher, M. +2 more
We investigate the role of the 11 yr solar cycle variations in the solar wind (SW) parameters on the flows in the heliosheath using a new three-dimensional time-dependent model of the interaction between the SW and the interstellar medium. For boundary conditions in the model we use realistic time and the latitudinal dependence of the SW parameter…
Structure and Morphology of X-Ray-selected Active Galactic Nucleus Hosts at 1 < z < 3 in the CANDELS-COSMOS Field
Fang, Guanwen; Kong, Xu; Chen, Yang +4 more
We analyze morphologies of the host galaxies of 35 X-ray-selected active galactic nuclei (AGNs) at z ~ 2 in the Cosmic Evolution Survey field using Hubble Space Telescope/WFC3 imaging taken from the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey. We build a control sample of 350 galaxies in total by selecting 10 non-active galaxies…
Phase-resolved XMM-Newton and Swift Observations of WR 25
Pandey, J. C.; Pandey, S. B.; Karmakar, Subhajeet
We present an analysis of long-term X-ray and optical observations of the Wolf-Rayet binary, WR 25. Using archival data from observations with the XMM-Newton and the Swift observatories, spanning over ~10 yr, we show that WR 25 is a periodic variable in X-rays with a period of 208 ± 3 days. X-ray light curves in the 0.5-10.0 keV energy band show p…
The WFPC2 Ultraviolet Survey: The Blue Straggler Population in NGC 5824
O'Connell, R. W.; Dalessandro, E.; Sanna, N. +3 more
We have used a combination of high-resolution Hubble Space Telescope Wide Field Planetary Camera 2 and wide-field ground-based observations, in ultraviolet and optical bands, to study the blue straggler star population of the massive outer halo globular cluster NGC 5824 over its entire radial extent. We have computed the center of the cluster and …
The Radial Distribution of X-Ray Binaries and Globular Clusters in NGC 4649 and their Relation with the Local Stellar Mass Density
Zezas, A.; Luo, B.; Gallagher, J. S. +7 more
We investigate the radial distribution of the low-mass X-ray binary (LMXB) population in the elliptical galaxy NGC 4649, using Chandra and Hubble data to separate the field and globular cluster (GC) populations. GCs with LMXBs have the same radial distribution as the parent red and blue GCs. The radial profile of field LMXBs follows the V-band pro…
Dramatic Change in Jupiter's Great Red Spot from Spacecraft Observations
de Pater, Imke; Wong, Michael H.; Orton, Glenn S. +5 more
Jupiter's Great Red Spot (GRS) is one of its most distinct and enduring features. Since the advent of modern telescopes, keen observers have noted its appearance and documented a change in shape from very oblong to oval, confirmed in measurements from spacecraft data. It currently spans the smallest latitude and longitude size ever recorded. Here …
The Second-generation z (Redshift) and Early Universe Spectrometer. I. First-light Observation of a Highly Lensed Local-ulirg Analog at High-z
Hasselfield, Matthew; Halpern, Mark; Menten, Karl M. +20 more
We recently commissioned our new spectrometer, the second-generation z(Redshift) and Early Universe Spectrometer (ZEUS-2) on the Atacama Pathfinder Experiment telescope. ZEUS-2 is a submillimeter grating spectrometer optimized for detecting the faint and broad lines from distant galaxies that are redshifted into the telluric windows from 200 to 85…
A Pulsation Search among Young Brown Dwarfs and Very-low-mass Stars
Cody, Ann Marie; Hillenbrand, Lynne A.
In 2005, Palla & Baraffe proposed that brown dwarfs (BDs) and very-low-mass stars (VLMSs; < 0.1 solar masses) may be unstable to radial oscillations during the pre-main-sequence deuterium burning phase. With associated periods of one to four hours, this potentially new class of pulsation offers unprecedented opportunities to probe the inter…