Search Publications
DIGIT survey of far-infrared lines from protoplanetary discs. II. CO
Henning, Thomas; Bouwman, Jeroen; van Dishoeck, Ewine F. +11 more
CO is an important component of a protoplanetary disc as it is one of the most abundant gas phase species. Furthermore, observations of CO transitions can be used as a diagnostic of the gas, tracing conditions in both the inner and outer disc. We present Herschel/PACS spectroscopy of a sample of 22 Herbig Ae/Be (HAEBEs) and eight T Tauri stars (TT…
Tidal disruption of a super-Jupiter by a massive black hole
Walter, R.; Nikołajuk, M.
Aims: A strong, hard X-ray flare was discovered (IGR J12580+0134) by INTEGRAL in 2011, and is associated to NGC 4845, a Seyfert 2 galaxy never detected at high-energy previously. To understand what happened we observed this event in the X-ray band on several occasions.
Methods: Follow-up observations with XMM-Newton, Swift, and MAXI are …
AGN host galaxies at redshift z ≈ 0.7: peculiar or not?
Heymans, C.; Taylor, A. N.; Gray, M. E. +21 more
Aims: We perform a quantitative morphological comparison between the hosts of active galactic nuclei (AGN) and quiescent galaxies at intermediate redshifts (z ≈ 0.7). The imaging data are taken from the large HST/ACS mosaics of the GEMS and STAGES surveys. Our main aim is to test whether nuclear activity at this cosmic epoch is triggered by m…
Indication for an intermediate-mass black hole in the globular cluster NGC 5286 from kinematics
Kissler-Patig, M.; de Zeeuw, P. T.; Neumayer, N. +6 more
Context. Intermediate-mass black holes (IMBHs) fill the gap between stellar-mass black holes and supermassive black holes (SMBHs). The existence of the latter is widely accepted, but there are only few detections of intermediate-mass black holes (102 - 105M⊙) so far. Simulations have shown that intermediate-mass bl…
Fragmentation and dynamical collapse of the starless high-mass star-forming region IRDC 18310-4
Smith, R.; Henning, Th.; Krause, O. +9 more
Context. Because of their short evolutionary time-scales, the earliest stages of high-mass star formation prior to the existence of any embedded heating source have barely been characterized until today.
Aims: We study the fragmentation and dynamical properties of a massive starless gas clump at the onset of high-mass star formation.
Met…
Vertical settling and radial segregation of large dust grains in the circumstellar disk of the Butterfly Star
Stapelfeldt, K. R.; Wolf, S.; Pontoppidan, K. M. +4 more
Context. Circumstellar disks are considered to be the environment for the formation of planets. The growth of dust grains in these disks is the first step in the core accretion-gas capture planet formation scenario. Indicators and evidence of disk evolution can be traced in spatially resolved images and the spectral energy distribution (SED) of th…
Full-sky CMB lensing reconstruction in presence of sky-cuts
Benabed, K.; Benoit-Lévy, A.; Cardoso, J. -F. +3 more
We consider the reconstruction of the CMB lensing potential and its power spectrum on the full sphere in presence of sky-cuts due to point sources and Galactic contamination. These two effects are treated separately. Small regions contaminated by point sources are filled in using constrained Gaussian realizations. The Galactic plane is simply remo…
Studying the properties of galaxy cluster morphology estimators
Böhringer, H.; Šuhada, R.; Ameglio, S. +1 more
X-ray observations of galaxy clusters reveal a large range of morphologies with various degrees of disturbance, showing that the assumptions of hydrostatic equilibrium and spherical shape, which are used to determine the cluster mass from X-ray data are not always satisfied. It is therefore important for the understanding of cluster properties as …
Gas-phase CO depletion and N2H+ abundances in starless cores
Henning, Th.; Krause, O.; Balog, Z. +10 more
Context. In the dense and cold interiors of starless molecular cloud cores, a number of chemical processes allow for the formation of complex molecules and the deposition of ice layers on dust grains. Dust density and temperature maps of starless cores derived from Herschel continuum observations constrain the physical structure of the cloud cores…
A detailed X-ray investigation of ζ Puppis. III. Spectral analysis of the whole RGS spectrum
Nazé, Y.; Rauw, G.; Hervé, A.
Context. ζ Pup is the X-ray brightest O-type star of the sky. This object was regularly observed with the RGS instrument onboard XMM-Newton for calibration purposes, which led to an unprecedented set of high-quality spectra.
Aims: We have previously reduced and extracted this data set and integrated it into the most detailed high-resolution X…