Search Publications
Evidence for a Clumpy, Rotating Gas Disk in a Submillimeter Galaxy at z = 4
Daddi, E.; Walter, F.; Riechers, D. +4 more
We present Karl G. Jansky Very Large Array observations of the CO(2-1) emission in the z = 4.05 submillimeter galaxy (SMG) GN20. These high-resolution data allow us to image the molecular gas at 1.3 kpc resolution just 1.6 Gyr after the big bang. The data reveal a clumpy, extended gas reservoir, 14 ± 4 kpc in diameter, in unprecedented detail. A d…
A Large Population of Massive Compact Post-starburst Galaxies at z > 1: Implications for the Size Evolution and Quenching Mechanism of Quiescent Galaxies
van Dokkum, Pieter G.; Franx, Marijn; Labbé, Ivo +4 more
We study the growth of the red sequence through the number density and structural evolution of a sample of young and old quiescent galaxies at 0 < z < 2. The galaxies are selected from the NEWFIRM Medium-Band Survey in the Cosmic Evolution Survey field. We find a large population of massive young recently quenched ("post-starburst") galaxies…
In-orbit performance of Herschel-HIFI
de Graauw, Th.; Braine, J.; Martín-Pintado, J. +96 more
Aims: In this paper the calibration and in-orbit performance of the Heterodyne Instrument for the Far-Infrared (HIFI) is described.
Methods: The calibration of HIFI is based on a combination of ground and in-flight tests. Dedicated ground tests to determine those instrument parameters that can only be measured accurately using controlled…
The Galactic WC stars. Stellar parameters from spectral analyses indicate a new evolutionary sequence
Sander, A.; Hamann, W. -R.; Todt, H.
Context. The life cycles of massive stars from the main sequence to their explosion as supernovae or gamma ray bursts are not yet fully clear, and the empirical results from spectral analyses are partly in conflict with current evolutionary models. The spectral analysis of Wolf-Rayet stars requires the detailed modeling of expanding stellar atmosp…
Simultaneous Planck, Swift, and Fermi observations of X-ray and γ-ray selected blazars
Tagliaferri, G.; Bonaldi, A.; Bonavera, L. +92 more
We present simultaneous Planck, Swift, Fermi, and ground-based data for 105 blazars belonging to three samples with flux limits in the soft X-ray, hard X-ray, and γ-ray bands, with additional 5GHz flux-density limits to ensure a good probability of a Planck detection. We compare our results to those of a companion paper presenting simultaneous Pla…
Reverberation Mapping Results for Five Seyfert 1 Galaxies
Skowron, J.; Kochanek, C. S.; Peterson, B. M. +40 more
We present the results from a detailed analysis of photometric and spectrophotometric data on five Seyfert 1 galaxies observed as a part of a recent reverberation mapping program. The data were collected at several observatories over a 140 day span beginning in 2010 August and ending in 2011 January. We obtained high sampling-rate light curves for…
XHIP: An extended hipparcos compilation
Anderson, E.; Francis, Ch.
We present the Extended Hipparcos Compilation (XHIP), a database of all stars in the New Reduction of the Hipparcos Catalog extensively cross-referenced with data from a broad survey of presently available sources. The resulting collection uniquely assigns 116 096 spectral classifications, 46 392 radial velocities, and 18 549 homogenized iron abun…
A Unified Empirical Model for Infrared Galaxy Counts Based on the Observed Physical Evolution of Distant Galaxies
Buat, Véronique; Daddi, Emanuele; Hezaveh, Yashar +10 more
We reproduce the mid-infrared to radio galaxy counts with a new empirical model based on our current understanding of the evolution of main-sequence (MS) and starburst (SB) galaxies. We rely on a simple spectral energy distribution (SED) library based on Herschel observations: a single SED for the MS and another one for SB, getting warmer with red…
A chemical model for the atmosphere of hot Jupiters
Agúndez, M.; Hersant, F.; Dobrijevic, M. +5 more
Context. The atmosphere of hot Jupiters can be probed by primary transit and secondary eclipse spectroscopy. Owing to the intense UV irradiation, mixing, and circulation, their chemical composition is maintained out of equilibrium and must be modeled with kinetic models.
Aims: Our purpose is to release a chemical network and the associated ra…
CANDELS: The Contribution of the Observed Galaxy Population to Cosmic Reionization
Papovich, Casey; Finkelstein, Steven L.; Dickinson, Mark +12 more
We present measurements of the specific ultraviolet luminosity density from a sample of 483 galaxies at 6 <~ z <~ 8. These galaxies were selected from new deep near-infrared Hubble Space Telescope imaging from the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey, Hubble UltraDeep Field 2009, and Wide Field Camera 3 Early Releas…