Search Publications
Planck intermediate results. XLI. A map of lensing-induced B-modes
Miville-Deschênes, M. -A.; Boulanger, F.; Bernard, J. -P. +178 more
The secondary cosmic microwave background (CMB) B-modes stem from the post-decoupling distortion of the polarization E-modes due to the gravitational lensing effect of large-scale structures. These lensing-induced B-modes constitute both a valuable probe of the dark matter distribution and an important contaminant for the extraction of the primary…
NuSTAR reveals the extreme properties of the super-Eddington accreting supermassive black hole in PG 1247+267
Harrison, F. A.; Stern, D.; Zhang, W. W. +26 more
PG1247+267 is one of the most luminous known quasars at z ~ 2 and is a strongly super-Eddington accreting supermassive black hole (SMBH) candidate. We obtained NuSTAR data of this intriguing source in December 2014 with the aim of studying its high-energy emission, leveraging the broad band covered by the new NuSTAR and the archival XMM-Newton dat…
Gaia Data Release 1. On-orbit performance of the Gaia CCDs at L2
Prusti, T.; Mora, A.; Brown, A. G. A. +19 more
The European Space Agency's Gaia satellite was launched into orbit around L2 in December 2013 with a payload containing 106 large-format scientific CCDs. The primary goal of the mission is to repeatedly obtain high-precision astrometric and photometric measurements of one thousand million stars over the course of five years. The scientific value o…
Probing deep photospheric layers of the quiet Sun with high magnetic sensitivity
Franz, M.; Schmidt, W.; Solanki, S. K. +31 more
Context. Investigations of the magnetism of the quiet Sun are hindered by extremely weak polarization signals in Fraunhofer spectral lines. Photon noise, straylight, and the systematically different sensitivity of the Zeeman effect to longitudinal and transversal magnetic fields result in controversial results in terms of the strength and angular …
Multiwavelength study of the flaring activity of Sagittarius A in 2014 February-April
Grosso, N.; Porquet, D.; Eckart, A. +8 more
Context. The supermassive black hole named Sgr A* is located at the dynamical center of the Milky Way. This closest supermassive black hole is known to have a luminosity several orders of magnitude lower than the Eddington luminosity. Flares coming from the Sgr A* environment can be observed in infrared, X-ray, and submillimeter wavelengths, but t…
Observations and analysis of a curved jet in the coma of comet 67P/Churyumov-Gerasimenko
Jorda, L.; Lamy, P. L.; Lara, L. M. +48 more
Aims: We analyze the physical properties and dynamical origin of a curved jet of comet 67P/Churyumov-Gerasimenko that was observed repeatedly in several nucleus rotations starting on May 30 and persisting until early August, 2015.
Methods: We simulated the motion of dust grains ejected from the nucleus surface under the influence of the …
Multi-band morpho-Spectral Component Analysis Deblending Tool (MuSCADeT): Deblending colourful objects
Starck, J. -L.; Courbin, F.; Joseph, R.
We introduce a new algorithm for colour separation and deblending of multi-band astronomical images called MuSCADeT which is based on Morpho-spectral Component Analysis of multi-band images. The MuSCADeT algorithm takes advantage of the sparsity of astronomical objects in morphological dictionaries such as wavelets and their differences in spectra…
Hot prominence detected in the core of a coronal mass ejection: Analysis of SOHO/UVCS Lα and SOHO/LASCO visible-light observations
Heinzel, P.; Anzer, U.; Jejčič, S. +2 more
Context. The paper deals with the physics of erupting prominences in the core of coronal mass ejections (CME).
Aims: We determine the physical parameters of an erupting prominence embedded in the core of a CME using SOHO/UVCS hydrogen Lα and Lβ lines and SOHO/LASCO visible light observations. In particular we analyze the CME event observed on…
Firedec: a two-channel finite-resolution image deconvolution algorithm
Jablonka, P.; Meylan, G.; Courbin, F. +2 more
We present a two-channel deconvolution method that decomposes images into a parametric point-source channel and a pixelized extended-source channel. Based on the central idea of the deconvolution algorithm proposed by Magain et al. (1998, ApJ, 494, 472), the method aims at improving the resolution of the data rather than at completely removing the…
The rotation-metallicity relation for the Galactic disk as measured in the Gaia DR1 TGAS and APOGEE data
Cropper, Mark; Kawata, Daisuke; Allende Prieto, Carlos
Aims: Previous studies have found that the Galactic rotation velocity-metallicity (V-[Fe/H]) relations for the thin and thick disk populations show negative and positive slopes, respectively. The first Gaia data release includes the Tycho-Gaia Astrometric Solution (TGAS) information, which we use to analyze the V-[Fe/H] relation for a strictl…