Search Publications
The metal-enriched host of an energetic γ-ray burst at z ≈ 1.6
Geier, S.; Milvang-Jensen, B.; Fynbo, J. P. U. +7 more
Context. The star-forming nature of long γ-ray burst (GRB) host galaxies provides invaluable constraints on the progenitors of GRBs and might open a short-cut to the characteristics of typical star-forming galaxies throughout the history of the Universe. Due to the absence of near-infrared (NIR) spectroscopy, however, detailed investigations, spec…
Tracking down R Coronae Borealis stars from their mid-infrared WISE colours
Tisserand, P.
Context. R Coronae Borealis stars (RCBs) are hydrogen-deficient and carbon-rich supergiant stars. They are very rare, with only ~50 actually known in our Galaxy. Interestingly, RCBs are strongly suspected of being the evolved merger product of two white dwarfs and could therefore be an important tool for understanding supernovae type Ia in the dou…
Time-resolved spectroscopy of BD+46°442: Gas streams and jet creation in a newly discovered evolved binary with a disk
Jorissen, A.; Frémat, Y.; Gorlova, N. +9 more
Context. Previous studies have shown that many post-asymptotic giant branch (AGB) stars with dusty disks are associated with single-lined binary stars. The inferred orbital separations are too small to accommodate a fully grown AGB star, hence these systems represent a new evolutionary channel that bypasses a full AGB evolution.
Aims: We wish…
The CHESS survey of the L1157-B1 shock: the dissociative jet shock as revealed by Herschel-PACS
Codella, C.; Ceccarelli, C.; Benedettini, M. +9 more
Outflows generated by protostars heavily affect the kinematics and chemistry of the hosting molecular cloud through strong shocks that enhance the abundance of some molecules. L1157 is the prototype of chemically active outflows, and a strong shock, called B1, is taking place in its blue lobe between the precessing jet and the hosting cloud. We pr…
Unveiling the nature of INTEGRAL objects through optical spectroscopy. IX. Twenty two more identifications, and a glance into the far hard X-ray Universe
Palazzi, E.; Minniti, D.; Masetti, N. +14 more
Since its launch in October 2002, the INTEGRAL satellite has revolutionized our knowledge of the hard X-ray sky thanks to its unprecedented imaging capabilities and source detection positional accuracy above 20 keV. Nevertheless, many of the newly-detected sources in the INTEGRAL sky surveys are of unknown nature. The combined use of available inf…
Study of LINER sources with broad Hα emission. Spectral energy distribution and multiwavelength correlations
Grosso, N.; Porquet, D.; Reeves, J. N. +2 more
Context. The geometry and physical properties of the accretion mode, and the radiative processes occurring in AGN-powered low ionization nuclear emission-line regions (LINERs) remain a riddle. Both a standard thin accretion disk and an inner-hot radiatively-inefficient accretion flow (RIAF) have been invoked. Models depending on only a jet have al…
Quantitative spectroscopy of Galactic BA-type supergiants. I. Atmospheric parameters
Przybilla, N.; Firnstein, M.
Context. BA-type supergiants show a high potential as versatile indicators for modern astronomy. This paper constitutes the first in a series that aims at a systematic spectroscopic study of Galactic BA-type supergiants. Various problems will be addressed, including in particular observational constraints on the evolution of massive stars and a de…
Neutron star masses from hydrodynamical effects in obscured supergiant high mass X-ray binaries
Walter, R.; Manousakis, A.; Blondin, J. M.
Context. A population of obscured supergiant high mass X-ray binaries has been discovered by INTEGRAL. X-ray wind tomography of IGR J17252-3616 inferred a slow wind velocity to account for the enhanced obscuration.
Aims: The main goal of this study is to understand under which conditions high obscuration could occur.
Methods: We have use…
C and N abundances of main sequence and subgiant branch stars in NGC 1851
Rejkuba, M.; Milone, A. P.; Marino, A. F. +6 more
We present the first chemical analysis of stars on the double subgiant branch (SGB) of the globular cluster NGC 1851. We obtained 48 Magellan IMACS spectra of subgiants and fainter stars covering the spectral region between 3650-6750 Å to derive C and N abundances from the spectral features at 4300 Å (G-band) and at ~3883 Å (CN). We added to our s…
Determination of binary asteroid orbits with a genetic-based algorithm
Berthier, J.; Marchis, F.; Vachier, F.
Aims: Over the past decade, discoveries of multiple and binary asteroid systems have played a significant role in our general understanding of small solar system bodies. Direct observations of satellites of asteroids are rare and difficult since they require the use of already over-subscribed facilities such as adaptive optics (AO) on large 8…