Search Publications
Sizes and Surface Brightness Profiles of Quiescent Galaxies at z ~ 2
van Dokkum, Pieter G.; Franx, Marijn; Szomoru, Daniel
We use deep Hubble Space Telescope Wide Field Camera 3 near-infrared imaging obtained of the GOODS-South field as part of the CANDELS survey to investigate a stellar mass-limited sample of quiescent galaxies at 1.5 < z < 2.5. We measure surface brightness profiles for these galaxies using a method that properly measures low surface brightnes…
Enhanced star formation rates in AGN hosts with respect to inactive galaxies from PEP-Herschel observations
Berta, S.; Magnelli, B.; Nordon, R. +35 more
We compare the average star formation (SF) activity in X-ray selected AGN hosts with a mass-matched control sample of inactive galaxies, including both star forming and quiescent sources, in the 0.5 < z < 2.5 redshift range. Recent observations carried out by PACS, the 60-210 µm photometric camera on board the Herschel Space Observator…
A far-infrared survey of bow shocks and detached shells around AGB stars and red supergiants
Blommaert, J. A. D. L.; Jorissen, A.; Ottensamer, R. +16 more
Aims: Our goal is to study the different morphologies associated to the interaction of the stellar winds of AGB stars and red supergiants with the interstellar medium (ISM) to follow the fate of the circumstellar matter injected into the interstellar medium.
Methods: Far-infrared Herschel/PACS images at 70 and 160 µm of a sample of…
Dissipationless Formation and Evolution of the Milky Way Nuclear Star Cluster
Mastrobuono-Battisti, Alessandra; Merritt, David; Antonini, Fabio +1 more
In one widely discussed model for the formation of nuclear star clusters (NSCs), massive globular clusters spiral into the center of a galaxy and merge to form the nucleus. It is now known that at least some NSCs coexist with supermassive black holes (SMBHs); this is the case, for instance, in the Milky Way. In this paper, we investigate how the p…
An over-massive black hole in the compact lenticular galaxy NGC 1277
van der Wel, Arjen; Gebhardt, Karl; van de Ven, Glenn +3 more
Most massive galaxies have supermassive black holes at their centres, and the masses of the black holes are believed to correlate with properties of the host-galaxy bulge component. Several explanations have been proposed for the existence of these locally established empirical relationships, including the non-causal, statistical process of galaxy…
The 4 Ms Chandra Deep Field-South Number Counts Apportioned by Source Class: Pervasive Active Galactic Nuclei and the Ascent of Normal Galaxies
Lehmer, B. D.; Hornschemeier, A. E.; Ptak, A. +13 more
We present 0.5-2 keV, 2-8 keV, 4-8 keV, and 0.5-8 keV (hereafter soft, hard, ultra-hard, and full bands, respectively) cumulative and differential number-count (log N-log S) measurements for the recently completed ≈4 Ms Chandra Deep Field-South (CDF-S) survey, the deepest X-ray survey to date. We implement a new Bayesian approach, which allows rel…
Spectrophotometric Libraries, Revised Photonic Passbands, and Zero Points for UBVRI, Hipparcos, and Tycho Photometry
Murphy, Simon; Bessell, Michael
We have calculated improved photonic passbands for the UBVRI, Hipparcos Hp, and Tycho BT and VT standard systems using the extensive spectrophotometric libraries of NGSL and MILES. Using the Hp passband, we adjusted the absolute flux levels of stars in the spectrophotometric libraries so that their synth…
Accurate fundamental parameters and detailed abundance patterns from spectroscopy of 93 solar-type Kepler targets
Kawaler, S. D.; Christensen-Dalsgaard, J.; García, R. A. +29 more
We present a detailed spectroscopic study of 93 solar-type stars that are targets of the NASA/Kepler mission and provide detailed chemical composition of each target. We find that the overall metallicity is well represented by Fe lines. Relative abundances of light elements (CNO) and α elements are generally higher for low-metallicity stars. Our s…
The suppression of star formation by powerful active galactic nuclei
Altieri, B.; Aussel, H.; Elbaz, D. +75 more
The old, red stars that constitute the bulges of galaxies, and the massive black holes at their centres, are the relics of a period in cosmic history when galaxies formed stars at remarkable rates and active galactic nuclei (AGN) shone brightly as a result of accretion onto black holes. It is widely suspected, but unproved, that the tight correlat…
The dust scaling relations of the Herschel Reference Survey
Clements, D. L.; Ciesla, L.; Boquien, M. +23 more
We combine new Herschel/SPIRE sub-millimeter observations with existing multiwavelength data to investigate the dust scaling relations of the Herschel Reference Survey, a magnitude-, volume-limited sample of ~300 nearby galaxies in different environments. We show that the dust-to-stellar mass ratio anti-correlates with stellar mass, stellar mass s…