Search Publications
3D model of hydrogen atmospheric escape from HD 209458b and HD 189733b: radiative blow-out and stellar wind interactions
Lecavelier des Etangs, A.; Bourrier, V.
Transit observations in the Lyman-α line of the hot-Jupiters HD 209458b and HD 189733b revealed strong signatures of neutral hydrogen escaping the planets' upper atmospheres. Here we present a 3D particle model of the dynamics of the escaping atoms. This model is used to calculate theoretical Lyman-α absorption line profiles, which can be directly…
The multi-thermal emission in solar active regions
Del Zanna, G.
We present simultaneous SDO AIA and Hinode EIS observations of the hot cores of active regions (ARs) and assess the dominant contributions to the AIA EUV bands. This is an extension of our previous work. We find good agreement between SDO AIA, EVE and EIS observations, using our new EIS calibration and the latest EVE v.3 data. We find that all the…
Formation and evolution of interstellar filaments. Hints from velocity dispersion measurements
André, Ph.; Arzoumanian, D.; Könyves, V. +1 more
We investigate the gas velocity dispersions of a sample of filaments recently detected as part of the Herschel Gould Belt Survey in the IC 5146, Aquila, and Polaris interstellar clouds. To measure these velocity dispersions, we use 13CO, C18O, and N2H+ line observations obtained with the IRAM 30 m telesc…
Revealing the cold dust in low-metallicity environments. I. Photometry analysis of the Dwarf Galaxy Survey with Herschel
Ciesla, L.; Boquien, M.; Roussel, H. +21 more
Context. We present new photometric data from our Herschel guaranteed time key programme, the Dwarf Galaxy Survey (DGS), dedicated to the observation of the gas and dust in low-metallicity environments. A total of 48 dwarf galaxies were observed with the PACS and SPIRE instruments onboard the Herschel Space Observatory at 70, 100, 160, 250, 350, a…
The VLT-FLAMES Tarantula Survey. XI. A census of the hot luminous stars and their feedback in 30 Doradus
van Loon, J. Th.; Crowther, P. A.; Herrero, A. +16 more
Context. The VLT-FLAMES Tarantula Survey has an extensive view of the copious number of massive stars in the 30 Doradus (30 Dor) star forming region of the Large Magellanic Cloud. These stars play a crucial role in our understanding of the stellar feedback in more distant, unresolved star forming regions.
Aims: The first comprehensive census …
The Earliest Phases of Star Formation (EPoS): a Herschel key project. The thermal structure of low-mass molecular cloud cores
Stecklum, B.; Henning, Th.; Krause, O. +19 more
Context. The temperature and density structure of molecular cloud cores are the most important physical quantities that determine the course of the protostellar collapse and the properties of the stars they form. Nevertheless, density profiles often rely either on the simplifying assumption of isothermality or on observationally poorly constrained…
Resolving stellar populations with crowded field 3D spectroscopy
Roth, M. M.; Kamann, S.; Wisotzki, L.
We describe a new method of extracting the spectra of stars from observations of crowded stellar fields with integral field spectroscopy (IFS). Our approach extends the well-established concept of crowded field photometry in images into the domain of 3-dimensional spectroscopic datacubes. The main features of our algorithm follow. (1) We assume th…
Multiwavelength campaign on Mrk 509. XII. Broad band spectral analysis
Kaastra, J. S.; Kriss, G. A.; Bianchi, S. +12 more
The origin of the different spectral components present in the high-energy (UV to X-rays/gamma-rays) spectra of Seyfert galaxies is still being debated a lot. One of the major limitations, in this respect, is the lack of really simultaneous broad-band observations that allow us to disentangle the behavior of each component and to better constrain …
TNOs are Cool: A survey of the trans-Neptunian region. VIII. Combined Herschel PACS and SPIRE observations of nine bright targets at 70-500 µm
Mottola, S.; Fornasier, S.; Lellouch, E. +17 more
Aims: Trans-Neptunian objects (TNOs) are bodies populating the Kuiper belt and they are believed to retain the most pristine and least altered material of the solar system. The Herschel open time key programme entitled "TNOs are Cool: A survey of the trans-Neptunian region" has been awarded 373 h to investigate the albedo, size distribution a…
Atmospheric escape from HD 189733b observed in H I Lyman-α: detailed analysis of HST/STIS September 2011 observations
Ehrenreich, D.; Lecavelier des Etangs, A.; Bourrier, V. +8 more
Observations of transits of the hot giant exoplanet