Search Publications
Hip 63510C, Hip 73786B, and nine new isolated high proper motion T dwarf candidates from UKIDSS DR6 and SDSS DR7
Scholz, R. -D.
Aims: Completing the poorly known substellar census of the solar neighbourhood, especially with respect to the coolest brown dwarfs, will lead to a better understanding of failed star formation processes and binary statistics with different environmental conditions.
Methods: Using UKIDSS data and their cross-correlation with the SDSS, we…
Distribution functions for magnetic fields on the quiet Sun
Stenflo, J. O.
The statistical properties of the highly structured magnetic field of the quiet Sun are best described in terms of distribution functions, in particular the probability density functions (PDF) for the flux densities and the angular distribution for the orientations of the field vector. They are needed to test the validity of various MHD simulation…
Evidence of a fast evolution of the UV luminosity function beyond redshift 6 from a deep HAWK-I survey of the GOODS-S field
Maiolino, R.; Dickinson, M.; Giavalisco, M. +21 more
Aims: We perform a deep search for galaxies in the redshift range 6.5≤ z≤ 7.5, to measure the evolution of the number density of luminous galaxies in this redshift range and derive useful constraints on the evolution of their luminosity function.
Methods: We present here the first results of an ESO Large Programme, which exploits the uni…
On the origin of [NeII] 12.81 µm emission from pre-main sequence stars: Disks, jets, and accretion
Güdel, M.; Henning, Th.; van Boekel, R. +6 more
Context. Extreme-ultraviolet (EUV) and X-ray photons from classical T Tauri stars are powerful ionization and heating agents that drive disk chemistry, disk instabilities, and photoevaporative flows. The mid-infrared fine-structure line of [Ne ii] at 12.81 µm has been proposed to trace gas in disk surface layers heated and ionized by stellar…
The solar-like CoRoT target HD 170987: spectroscopic and seismic observations
Auvergne, M.; García, R. A.; Chaplin, W. J. +22 more
Context. The CoRoT mission is in its third year of observation and the data from the second long run in the galactic centre direction are being analysed. The solar-like oscillating stars that have been observed up to now have given some interesting results, specially concerning the amplitudes that are lower than predicted. We present here the resu…
Herschel-PACS observation of the 10 Myr old T Tauri disk TW Hya. Constraining the disk gas mass
Pinte, C.; Ménard, F.; Duchêne, G. +49 more
Planets are formed in disks around young stars. With an age of ~10 Myr, TW Hya is one of the nearest T Tauri stars that is still surrounded by a relatively massive disk. In addition a large number of molecules has been found in the TW Hya disk, making TW Hya the perfect test case in a large survey of disks with Herschel-PACS to directly study thei…
Detection of interstellar oxidaniumyl: Abundant H2O+ towards the star-forming regions DR21, Sgr B2, and NGC6334
Menten, K. M.; Boulanger, F.; Falgarone, E. +99 more
Aims: We identify a prominent absorption feature at 1115 GHz, detected in first HIFI spectra towards high-mass star-forming regions, and interpret its astrophysical origin.
Methods: The characteristic hyperfine pattern of the H2O+ ground-state rotational transition, and the lack of other known low-energy transitions…
Another look at the BL Lacertae flux and spectral variability. Observations by GASP-WEBT, XMM-Newton, and Swift in 2008-2009
Lähteenmäki, A.; Umana, G.; Capetti, A. +52 more
Aims: In a previous study we suggested that the broad-band emission and variability properties of BL Lacertae can be accounted for by a double synchrotron emission component with related inverse-Compton emission from the jet, plus thermal radiation from the accretion disc. Here we investigate the matter with further data extending over a wide…
X-ray variation statistics and wind clumping in Vela X-1
Klochkov, D.; Wilms, J.; Pottschmidt, K. +8 more
We investigate the structure of the wind in the neutron star X-ray binary system Vela X-1 by analyzing its flaring behavior. Vela X-1 shows constant flaring, with some flares reaching fluxes of more than 3.0 Crab between 20-60 keV for several 100 s, while the average flux is around 250 mCrab. We analyzed all archival INTEGRAL data, calculating the…
TANGO I: Interstellar medium in nearby radio galaxies. Molecular gas
Lim, J.; Combes, F.; Leon, S. +1 more
Context. Powerful radio-AGN are hosted by massive elliptical galaxies that are usually very poor in molecular gas. Nevertheless, gas is needed at their very center to feed the nuclear activity.
Aims: We study the molecular gas properties (i.e., mass, kinematics, distribution, origin) of these objects, and compare them with results for other k…