Search Publications
New PARSEC evolutionary tracks of massive stars at low metallicity: testing canonical stellar evolution in nearby star-forming dwarf galaxies
Slemer, Alessandra; Girardi, Léo; Marigo, Paola +4 more
We extend the PARSEC library of stellar evolutionary tracks by computing new models of massive stars, from 14 to 350 M⊙. The input physics is the same used in the PARSEC V1.1 version, but for the mass-loss rate from considering the most recent updates in the literature. We focus on low metallicity, Z = 0.001 and Z = 0.004, for which the…
Planets and stellar activity: hide and seek in the CoRoT-7 system
Deleuil, M.; Moutou, C.; Queloz, D. +12 more
Since the discovery of the transiting super-Earth CoRoT-7b, several investigations have yielded different results for the number and masses of planets present in the system, mainly owing to the star's high level of activity. We re-observed CoRoT-7 in 2012 January with both HARPS and CoRoT, so that we now have the benefit of simultaneous radial-vel…
Galaxy Stellar Mass Functions from ZFOURGE/CANDELS: An Excess of Low-mass Galaxies since z = 2 and the Rapid Buildup of Quiescent Galaxies
Papovich, Casey; Kelson, Daniel D.; Kacprzak, Glenn G. +16 more
Using observations from the FourStar Galaxy Evolution Survey (ZFOURGE), we obtain the deepest measurements to date of the galaxy stellar mass function (SMF) at 0.2 < z < 3. ZFOURGE provides well-constrained photometric redshifts made possible through deep medium-bandwidth imaging at 1-2 µm. We combine this with Hubble Space Telescope i…
Measuring Black Hole Spin Using X-Ray Reflection Spectroscopy
Reynolds, Christopher S.
I review the current status of X-ray reflection (a.k.a. broad iron line) based black hole spin measurements. This is a powerful technique that allows us to measure robust black hole spins across the mass range, from the stellar-mass black holes in X-ray binaries to the supermassive black holes in active galactic nuclei. After describing the basic …
The 1% Concordance Hubble Constant
Larson, D.; Weiland, J. L.; Hinshaw, G. +1 more
The determination of the Hubble constant has been a central goal in observational astrophysics for nearly a hundred years. Extraordinary progress has occurred in recent years on two fronts: the cosmic distance ladder measurements at low redshift and cosmic microwave background (CMB) measurements at high redshift. The CMB is used to predict the cur…
Planck 2013 results. XVII. Gravitational lensing by large-scale structure
Kneissl, R.; Miville-Deschênes, M. -A.; Bernard, J. -P. +238 more
On the arcminute angular scales probed by Planck, the cosmic microwave background (CMB) anisotropies are gently perturbed by gravitational lensing. Here we present a detailed study of this effect, detecting lensing independently in the 100, 143, and 217 GHz frequency bands with an overall significance of greater than 25σ. We use thetemperature-gra…
Molecular line emission in NGC 1068 imaged with ALMA. I. An AGN-driven outflow in the dense molecular gas
Tacconi, L. J.; Hunt, L. K.; Colina, L. +23 more
Aims: We investigate the fueling and the feedback of star formation and nuclear activity in
Methods: We have used the A…
The frequency of planetary debris around young white dwarfs
Gänsicke, B. T.; Koester, D.; Farihi, J.
Context. Heavy metals in the atmospheres of white dwarfs are thought in many cases to be accreted from a circumstellar debris disk, which was formed by the tidal disruption of a rocky planetary body within the Roche radius of the star. The abundance analysis of photospheric elements and conclusions about the chemical composition of the accreted ma…
Transient Water Vapor at Europa's South Pole
Nimmo, Francis; Saur, Joachim; Roth, Lorenz +4 more
In November and December 2012, the Hubble Space Telescope (HST) imaged Europa's ultraviolet emissions in the search for vapor plume activity. We report statistically significant coincident surpluses of hydrogen Lyman-α and oxygen OI 130.4-nanometer emissions above the southern hemisphere in December 2012. These emissions were persistently found in…
The applicability of far-infrared fine-structure lines as star formation rate tracers over wide ranges of metallicities and galaxy types
Lebouteiller, Vianney; De Looze, Ilse; Baes, Maarten +19 more
Aims: We analyze the applicability of far-infrared fine-structure lines [Cii] 158 µm, [Oi] 63 µm, and [Oiii] 88 µm to reliably trace the star formation rate (SFR) in a sample of low-metallicity dwarf galaxies from the Herschel Dwarf Galaxy Survey and, furthermore, extend the analysis to a broad sample of galaxies of various …