Search Publications
Compton-thick Accretion in the Local Universe
Bauer, F. E.; Gandhi, P.; Ricci, C. +3 more
Heavily obscured accretion is believed to represent an important stage in the growth of supermassive black holes and to play an important role in shaping the observed spectrum of the cosmic X-ray background. Hard X-ray (E > 10 keV) selected samples are less affected by absorption than samples selected at lower energies, and are therefore one of…
Hubble Space Telescope Combined Strong and Weak Lensing Analysis of the CLASH Sample: Mass and Magnification Models and Systematic Uncertainties
Donahue, Megan; Broadhurst, Tom; Frye, Brenda L. +23 more
We present results from a comprehensive lensing analysis in Hubble Space Telescope (HST) data of the complete Cluster Lensing And Supernova survey with Hubble cluster sample. We identify previously undiscovered multiple images, allowing improved or first constraints on the cluster inner mass distributions and profiles. We combine these strong lens…
Space Telescope and Optical Reverberation Mapping Project. II. Swift and HST Reverberation Mapping of the Accretion Disk of NGC 5548
Brandt, W. N.; Kriss, G. A.; Ely, J. +47 more
Recent intensive Swift monitoring of the Seyfert 1 galaxy NGC 5548 yielded 282 usable epochs over 125 days across six UV/optical bands and the X-rays. This is the densest extended active galactic nucleus (AGN) UV/optical continuum sampling ever obtained, with a mean sampling rate <0.5 day. Approximately daily Hubble Space Telescope UV sampling …
Weighing the giants - IV. Cosmology and neutrino mass
Kelly, Patrick L.; Allen, Steven W.; Ebeling, Harald +14 more
We employ robust weak gravitational lensing measurements to improve cosmological constraints from measurements of the galaxy cluster mass function and its evolution, using X-ray selected clusters detected in the ROSAT All-Sky Survey. Our lensing analysis constrains the absolute mass scale of such clusters at the 8 per cent level, including both st…
Multiple images of a highly magnified supernova formed by an early-type cluster galaxy lens
Fontana, Adriano; Weiner, Benjamin J.; Schmidt, Kasper B. +28 more
In 1964, Refsdal hypothesized that a supernova whose light traversed multiple paths around a strong gravitational lens could be used to measure the rate of cosmic expansion. We report the discovery of such a system. In Hubble Space Telescope imaging, we have found four images of a single supernova forming an Einstein cross configuration around a r…
The Tycho-Gaia astrometric solution . How to get 2.5 million parallaxes with less than one year of Gaia data
Michalik, Daniel; Lindegren, Lennart; Hobbs, David
Context. The first release of astrometric data from Gaia will contain the mean stellar positions and magnitudes from the first year of observations, and proper motions from the combination of Gaia data with Hipparcos prior information (HTPM).
Aims: We study the potential of using the positions from the Tycho-2 Catalogue as additional informat…
The galaxy stellar mass function at 3.5 ≤z ≤ 7.5 in the CANDELS/UDS, GOODS-South, and HUDF fields
Ferguson, H. C.; Finkelstein, S. L.; Giavalisco, M. +38 more
Context. The form and evolution of the galaxy stellar mass function (GSMF) at high redshifts provide crucial information on star formation history and mass assembly in the young Universe, close or even prior to the epoch of reionization.
Aims: We used the unique combination of deep optical/near-infrared/mid-infrared imaging provided by HST, S…
Bounds on very low reheating scenarios after Planck
Lattanzi, M.; de Salas, P. F.; Miele, G. +3 more
We consider the case of very low reheating scenarios [TRH∼O (MeV ) ] with a better calculation of the production of the relic neutrino background (with three-flavor oscillations). At 95% confidence level, a lower bound on the reheating temperature TRH>4.1 MeV is obtained from big bang nucleosynthesis, while TRH&…
Gaia FGK benchmark stars: Effective temperatures and surface gravities
Gustafsson, B.; Soubiran, C.; Heiter, U. +3 more
Context. In the era of large Galactic stellar surveys, carefully calibrating and validating the data sets has become an important and integral part of the data analysis. Moreover, new generations of stellar atmosphere models and spectral line formation computations need to be subjected to benchmark tests to assess any progress in predicting stella…
Evolution of the dust emission of massive galaxies up to z = 4 and constraints on their dominant mode of star formation
Buat, Véronique; Daddi, Emanuele; Ilbert, Olivier +19 more
We aim to measure the average dust and molecular gas content of massive star-forming galaxies (>3 × 1010M⊙) up to z = 4 in the COSMOS field to determine if the intense star formation observed at high redshift is induced by major mergers or is caused by large gas reservoirs. Firstly, we measured the evolution of the average…