Search Publications
X-ray follow-ups of XSS J12270-4859: a low-mass X-ray binary with gamma-ray Fermi-LAT association
Mukai, K.; Belloni, T.; de Martino, D. +10 more
Context. XSS J1227.0-4859 is a peculiar, hard X-ray source recently positionally associated to the Fermi-LAT source 1FGL J1227.9-4852/2FGL J1227.7-4853. Multi-wavelength observations have added information on this source, indicating a low-luminosity low-mass X-ray binary (LMXB), but its nature is still unclear.
Aims: To progress in our unders…
Magnesium in the atmosphere of the planet HD 209458 b: observations of the thermosphere-exosphere transition region
Ehrenreich, D.; Lecavelier des Etangs, A.; Bourrier, V. +8 more
The planet HD 209458 b is one of the most well studied hot-Jupiter exoplanets. The upper atmosphere of this planet has been observed through ultraviolet/optical transit observations with H i observation of the exosphere revealing atmospheric escape. At lower altitudes just below the thermosphere, detailed observations of the Na i absorption line h…
Constraining turbulence and conduction in the hot ICM through density perturbations
Churazov, E.; Gaspari, M.
Turbulence and conduction can dramatically affect the evolution of baryons in the universe; current constraints are however rare and uncertain. Using 3D high-resolution hydrodynamic simulations, tracking both electrons and ions, we study the effects of turbulence and conduction in the hot intracluster medium. We show how the power spectrum of the …
Limits on intermediate-mass black holes in six Galactic globular clusters with integral-field spectroscopy
Kissler-Patig, M.; de Zeeuw, P. T.; Neumayer, N. +6 more
Context. The formation of supermassive black holes at high redshift still remains a puzzle to astronomers. No accretion mechanism can explain the fast growth from a stellar mass black hole to several billion solar masses in less than one Gyr. The growth of supermassive black holes becomes reasonable only when starting from a massive seed black hol…
Interstellar medium composition through X-ray spectroscopy of low-mass X-ray binaries
Kaastra, J. S.; Costantini, E.; Pinto, C. +1 more
Context. The diffuse interstellar medium (ISM) is an integral part of the evolution of the entire Galaxy. Metals are produced by stars and their abundances are the direct testimony of the history of stellar evolution. However, the interstellar dust composition is not well known and the total abundances are yet to be accurately determined.
Aim…
Water in star-forming regions with Herschel (WISH). III. Far-infrared cooling lines in low-mass young stellar objects
Liseau, R.; Fedele, D.; van Dishoeck, E. F. +22 more
Context. Understanding the physical phenomena involved in the earlierst stages of protostellar evolution requires knowledge of the heating and cooling processes that occur in the surroundings of a young stellar object. Spatially resolved information from its constituent gas and dust provides the necessary constraints to distinguish between differe…
The mean star-forming properties of QSO host galaxies
Berta, S.; Magnelli, B.; Nordon, R. +22 more
Quasi-stellar objects (QSOs) occur in galaxies in which supermassive black holes (SMBHs) are growing substantially through rapid accretion of gas. Many popular models of the co-evolutionary growth of galaxies and black holes predict that QSOs are also sites of substantial recent star formation (SF), mediated by important processes, such as major m…
Macroclumping as solution of the discrepancy between Hα and P v mass loss diagnostics for O-type stars
Hamann, W. -R.; Oskinova, L. M.; Aret, A. +3 more
Context. Recent studies of O-type stars have demonstrated that discrepant mass-loss rates are obtained when different diagnostic methods are employed. Fitting the unsaturated UV resonance lines (e.g., P v) gives drastically lower values than obtained from the Hα emission. Wind inhomogeneity (so-called "clumping") may be the main cause of this disc…
Improved photometric calibration of the SNLS and the SDSS supernova surveys
Kessler, R.; Marriner, J.; Sako, M. +13 more
Context. We present a combined photometric calibration of the Supernova Legacy Survey (SNLS) and the SDSS supernova survey, which results from a joint effort of the SDSS and the SNLS collaborations.
Aims: Our primary motivation is to eventually sharpen cosmological constraints derived from type Ia supernova measurements by improving the accur…
Hubble Space Telescope detection of oxygen in the atmosphere of exoplanet HD 189733b
Ballester, G. E.; Ben-Jaffel, L.
Detecting heavy atoms in the inflated atmospheres of giant exoplanets that orbit close to their parent stars is a key factor for understanding their bulk composition, their evolution, and the processes that drive their expansion and interaction with the impinging stellar wind. Unfortunately, very few detections have been made thus far. Here, we us…