Search Publications

Large heterogeneities in comet 67P as revealed by active pits from sinkhole collapse
DOI: 10.1038/nature14564 Bibcode: 2015Natur.523...63V

Bertaux, Jean-Loup; Naletto, Giampiero; Debei, Stefano +64 more

Pits have been observed on many cometary nuclei mapped by spacecraft. It has been argued that cometary pits are a signature of endogenic activity, rather than impact craters such as those on planetary and asteroid surfaces. Impact experiments and models cannot reproduce the shapes of most of the observed cometary pits, and the predicted collision …

2015 Nature
Rosetta 168
High-precision Photometric Redshifts from Spitzer/IRAC: Extreme [3.6] - [4.5] Colors Identify Galaxies in the Redshift Range z ∼ 6.6 - 6.9
DOI: 10.1088/0004-637X/801/2/122 Bibcode: 2015ApJ...801..122S

Holwerda, Benne; Franx, Marijn; Labbé, Ivo +7 more

One of the most challenging aspects of studying galaxies in the z≳ 7 universe is the infrequent confirmation of their redshifts through spectroscopy, a phenomenon thought to occur from the increasing opacity of the intergalactic medium to Lyα photons at z\gt 6.5. The resulting redshift uncertainties inhibit the efficient search for [C ii] in z∼ 7 …

2015 The Astrophysical Journal
eHST 168
Probing the role of the galactic environment in the formation of stellar clusters, using M83 as a test bench
DOI: 10.1093/mnras/stv1203 Bibcode: 2015MNRAS.452..246A

Bastian, N.; Adamo, A.; Silva-Villa, E. +2 more

We present a study of the M83 cluster population, covering the disc of the galaxy between radii of 0.45 and 4.5 kpc. We aim to probe the properties of the cluster population as a function of distance from the galactic centre. We observe a net decline in cluster formation efficiency (Γ, i.e. amount of star formation happening in bound clusters) fro…

2015 Monthly Notices of the Royal Astronomical Society
eHST 168
Spectroscopic Evidence for a Temperature Inversion in the Dayside Atmosphere of Hot Jupiter WASP-33b
DOI: 10.1088/0004-637X/806/2/146 Bibcode: 2015ApJ...806..146H

Deming, Drake; Madhusudhan, Nikku; Knutson, Heather +2 more

We present observations of two occultations of the extrasolar planet WASP-33b using the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope, which allow us to constrain the temperature structure and composition of its dayside atmosphere. WASP-33b is the most highly irradiated hot Jupiter discovered to date, and the only exoplanet known to orb…

2015 The Astrophysical Journal
eHST 167
A remarkably flat relationship between the average star formation rate and AGN luminosity for distant X-ray AGN
DOI: 10.1093/mnras/stv1678 Bibcode: 2015MNRAS.453..591S

Alexander, D. M.; Swinbank, A. M.; Del Moro, A. +5 more

In this study, we investigate the relationship between the star formation rate (SFR) and AGN luminosity (L_AGN) for ∼2000 X-ray detected AGN. The AGN span over three orders of magnitude in X-ray luminosity (10^{42} < L_{2-8 keV} < 10^{45.5} erg s^{-1}) and are in the redshift range z = 0.2-2.5. Using infrared (IR) photometry (8-500 µ m…

2015 Monthly Notices of the Royal Astronomical Society
Herschel 166
XMM-Newton and Chandra cross-calibration using HIFLUGCS galaxy clusters . Systematic temperature differences and cosmological impact
DOI: 10.1051/0004-6361/201424085 Bibcode: 2015A&A...575A..30S

Lovisari, L.; David, L.; Reiprich, T. H. +2 more

Context. Robust X-ray temperature measurements of the intracluster medium (ICM) of galaxy clusters require an accurate energy-dependent effective area calibration. Since the hot gas X-ray emission of galaxy clusters does not vary on relevant timescales, they are excellent cross-calibration targets. Moreover, cosmological constraints from clusters …

2015 Astronomy and Astrophysics
Planck XMM-Newton 166
CLASH-VLT: Insights on the Mass Substructures in the Frontier Fields Cluster MACS J0416.1-2403 through Accurate Strong Lens Modeling
DOI: 10.1088/0004-637X/800/1/38 Bibcode: 2015ApJ...800...38G

Zitrin, A.; Grillo, C.; Balestra, I. +25 more

We present a detailed mass reconstruction and a novel study on the substructure properties in the core of the Cluster Lensing And Supernova survey with Hubble (CLASH) and Frontier Fields galaxy cluster MACS J0416.1-2403. We show and employ our extensive spectroscopic data set taken with the VIsible Multi-Object Spectrograph instrument as part of o…

2015 The Astrophysical Journal
eHST 166
Merger-driven Fueling of Active Galactic Nuclei: Six Dual and Offset AGNs Discovered with Chandra and Hubble Space Telescope Observations
DOI: 10.1088/0004-637X/806/2/219 Bibcode: 2015ApJ...806..219C

Greene, Jenny E.; Zakamska, Nadia L.; Comerford, Julia M. +4 more

Dual active galactic nuclei (AGNs) and offset AGNs are kpc-scale separation supermassive black holes pairs created during galaxy mergers, where both or one of the black holes are AGNs, respectively. These dual and offset AGNs are valuable probes of the link between mergers and AGNs but are challenging to identify. Here we present Chandra/ACIS obse…

2015 The Astrophysical Journal
eHST 165
Redistribution of particles across the nucleus of comet 67P/Churyumov-Gerasimenko
DOI: 10.1051/0004-6361/201526049 Bibcode: 2015A&A...583A..17T

Jorda, L.; Lamy, P. L.; Lara, L. M. +52 more

Context. We present an investigation of the surface properties of areas on the nucleus of comet 67P/Churyumov-Gerasimenko.
Aims: We aim to show that transport of material from one part of the cometary nucleus to another is a significant mechanism that influences the appearance of the nucleus and the surface thermal properties.
Methods: W…

2015 Astronomy and Astrophysics
Rosetta 165
The diurnal cycle of water ice on comet 67P/Churyumov-Gerasimenko
DOI: 10.1038/nature14869 Bibcode: 2015Natur.525..500D

Langevin, Y.; Bellucci, G.; Jaumann, R. +77 more

Observations of cometary nuclei have revealed a very limited amount of surface water ice, which is insufficient to explain the observed water outgassing. This was clearly demonstrated on comet 9P/Tempel 1, where the dust jets (driven by volatiles) were only partially correlated with the exposed ice regions. The observations of 67P/Churyumov-Gerasi…

2015 Nature
Rosetta 164