Search Publications
An upper limit for the water outgassing rate of the main-belt comet 176P/LINEAR observed with Herschel/HIFI
Küppers, M.; Hartogh, P.; Lellouch, E. +15 more
176P/LINEAR is a member of the new cometary class known as main-belt comets (MBCs). It displayed cometary activity shortly during its 2005 perihelion passage, which may be driven by the sublimation of subsurface ices. We have therefore searched for emission of the H2O 110-101 ground state rotational line at 557 GHz…
4U 1626-67 as seen by Suzaku before and after the 2008 torque reversal
Pottschmidt, K.; Wilson-Hodge, C. A.; Camero-Arranz, A. +3 more
Aims: The accretion-powered pulsar 4U 1626-67 experienced a new torque reversal at the beginning of 2008, after about 18 years of steadily spinning down. The main goal of the present work is to study this recent torque reversal that occurred in February 2008.
Methods: We present a spectral analysis of this source using two pointed observ…
The onset of high-mass star formation in the direct vicinity of the Galactic mini-starburst W43
Henning, Th.; Krause, O.; Beuther, H. +10 more
Context. The earliest stages of high-mass star formation are still poorly characterized. Densities, temperatures and kinematics are crucial parameters for simulations of high-mass star formation. It is also unknown whether the initial conditions vary with environment.
Aims: We want to investigate the youngest massive gas clumps in the environ…
Spectral and timing properties of the accreting X-ray millisecond pulsar IGR J17498-2921
Stella, L.; Bozzo, E.; Kuiper, L. +5 more
Context. IGR J17498-2921 is the third X-ray transient accreting millisecond pulsar discovered by INTEGRAL. It was in outburst for about 40 days beginning on August 08, 2011.
Aims: We analyze the spectral and timing properties of the object and the characteristics of X-ray bursts to constrain the physical processes responsible for the X-ray pr…
Thermal infrared properties of classical and type II Cepheids. Diffraction limited 10 µm imaging with VLT/VISIR
Kervella, P.; Mérand, A.; Gallenne, A.
We present new thermal infrared (IR) photometry and spectral energy distributions (SEDs) of eight classical Cepheids (type I) and three type II Cepheids, using VISIR thermal IR photometric measurements, supplemented with literature data. We used the BURST mode of the instrument to get diffraction-limited images at 8.59, 11.25, and 11.85 µm. …
An HST search for planets in the lower main sequence of the globular cluster NGC 6397
Bedin, L. R.; Rich, R. M.; Piotto, G. +2 more
Searches for planetary transits carried out in open and globular clusters have to date yielded only a handful of weak, unconfirmed candidates. These results have been interpreted as either being insignificant, or evidence that the cluster chemical or dynamical environment inhibits planetary formation or survival. Most campaigns have been limited b…
H2O line mapping at high spatial and spectral resolution. Herschel observations of the VLA 1623 outflow
Liseau, R.; Benedettini, M.; van Dishoeck, E. F. +12 more
Context. Apart from being an important coolant, water is known to be a tracer of high-velocity molecular gas. Recent models predict relatively high abundances behind interstellar shockwaves. The dynamical and physical conditions of the water emitting gas, however, are not fully understood yet. Using the Herschel Space Observatory, it is now possib…
Herschel far-IR observations of the Chamaeleon molecular cloud complex . Chamaeleon I: A first view of young stellar objects in the cloud
Prusti, T.; Pilbratt, G. L.; André, Ph. +12 more
Context. The Herschel Gould Belt survey of nearby star forming regions is providing great insights into the early stages of the formation and the evolution of stars and their circumstellar disks. The Chamaeleon I dark cloud is an elongated region of dense dust and gas where star formation is ongoing in two centres, a northern region centred on Ced…
High frame rate imaging based photometry. Photometric reduction of data from electron-multiplying charge coupled devices (EMCCDs)
Grundahl, F.; Jørgensen, U. G.; Harpsøe, K. B. W. +1 more
Context. The EMCCD is a type of CCD that delivers fast readout times and negligible readout noise, making it an ideal detector for high frame rate applications which improve resolution, like lucky imaging or shift-and-add. This improvement in resolution can potentially improve the photometry of faint stars in extremely crowded fields significantly…
Strong interactions between g- and p-modes in the hybrid γ Doradus-δ Scuti CoRoT star ID 105733033
Mathias, P.; Debosscher, J.; Chapellier, E. +2 more
Context. The presence of stellar p- and g-modes allows us to test stellar structure models in great detail from the core to the envelope. As the driving mechanisms are not yet fully understood, the first important step is to provide clear evidence of these pulsation modes.
Aims: Recent space missions have confirmed that the γ Doradus and the …