Search Publications
Water in star-forming regions with Herschel (WISH). II. Evolution of 557 GHz 110-101 emission in low-mass protostars
Liseau, R.; van Dishoeck, E. F.; Bergin, E. A. +22 more
Context. Water is a key tracer of dynamics and chemistry in low-mass star-forming regions, but spectrally resolved observations have so far been limited in sensitivity and angular resolution, and only data from the brightest low-mass protostars have been published.
Aims: The first systematic survey of spectrally resolved water emission in 29 …
The M31 Velocity Vector. II. Radial Orbit toward the Milky Way and Implied Local Group Mass
Anderson, Jay; van der Marel, Roeland P.; Beaton, Rachael L. +5 more
We determine the velocity vector of M31 with respect to the Milky Way and use this to constrain the mass of the Local Group, based on Hubble Space Telescope proper-motion measurements of three fields presented in Paper I. We construct N-body models for M31 to correct the measurements for the contributions from stellar motions internal to M31. This…
On the Cluster Physics of Sunyaev-Zel'dovich and X-Ray Surveys. I. The Influence of Feedback, Non-thermal Pressure, and Cluster Shapes on Y-M Scaling Relations
Bond, J. R.; Battaglia, N.; Sievers, J. L. +1 more
The utility of large Sunyaev-Zel'dovich (SZ) surveys for determining cosmological parameters from cluster abundances is limited by the theoretical uncertainties in the integrated SZ-flux-to-mass relation, Y-M. We explore how non-thermal pressure and the anisotropic shape of the gas distribution of the intracluster medium (ICM) impacts Y-M scaling …
The warm gas atmosphere of the HD 100546 disk seen by Herschel. Evidence of a gas-rich, carbon-poor atmosphere?
van Dishoeck, E. F.; Bruderer, S.; Herczeg, G. J. +1 more
Context. With the Herschel Space Observatory, lines of simple molecules (C+, O, and high-J lines of CO, Jup ≳ 14) have been observed in the atmosphere of protoplanetary disks. When combined with ground-based data on [C i], all principle forms of carbon can be studied. These data allow us to test model predictions for the main…
Temporal variations in the evaporating atmosphere of the exoplanet HD 189733b
Ehrenreich, D.; Lecavelier des Etangs, A.; Bourrier, V. +8 more
Atmospheric escape has been detected from the exoplanet
The Dependence of Quenching upon the Inner Structure of Galaxies at 0.5 <= z < 0.8 in the DEEP2/AEGIS Survey
Bell, Eric F.; Kocevski, Dale D.; Koekemoer, Anton M. +25 more
The shutdown of star formation in galaxies is generally termed "quenching." Quenching may occur through a variety of processes, e.g., active galactic nucleus (AGN) feedback, stellar feedback, or the shock heating of gas in the dark matter halo. However, which mechanism(s) is, in fact, responsible for quenching is still in question. This paper addr…
Two stellar-mass black holes in the globular cluster M22
Strader, Jay; Maccarone, Thomas J.; Seth, Anil C. +2 more
Hundreds of stellar-mass black holes probably form in a typical globular star cluster, with all but one predicted to be ejected through dynamical interactions. Some observational support for this idea is provided by the lack of X-ray-emitting binary stars comprising one black hole and one other star (`black-hole/X-ray binaries') in Milky Way globu…
Galaxy properties from the ultraviolet to the far-infrared: Λ cold dark matter models confront observations
Somerville, Rachel S.; Primack, Joel R.; Domínguez, Alberto +1 more
We combine a semi-analytic model of galaxy formation with simple analytic recipes describing the absorption and re-emission of starlight by dust in the interstellar medium of galaxies. We use the resulting models to predict galaxy counts and luminosity functions from the far-ultraviolet (FUV) to the submillimetre, from redshift five to the present…
Understanding Dual Active Galactic Nucleus Activation in the nearby Universe
Koss, Michael; Veilleux, Sylvain; Mushotzky, Richard +3 more
We study the fraction of dual active galactic nuclei (AGNs) in a sample of 167 nearby (z < 0.05), moderate-luminosity, ultra-hard X-ray-selected AGNs from the all-sky Swift Burst Alert Telescope (BAT) survey. Combining new Chandra and Gemini observations together with optical and X-ray observations, we find that the dual AGN frequency at scales…
Large-amplitude Variations of an L/T Transition Brown Dwarf: Multi-wavelength Observations of Patchy, High-contrast Cloud Features
Marley, Mark; Radigan, Jacqueline; Saumon, Didier +3 more
We present multiple-epoch photometric monitoring in the J, H, and Ks bands of the T1.5 dwarf 2MASS J21392676+0220226 (2M2139), revealing persistent, periodic (P = 7.721 ± 0.005 hr) variability with a peak-to-peak amplitude as high as 26% in the J band. The light curve shape varies on a timescale of days, suggesting that evolving atmosph…