Search Publications
Predicted gamma-ray line emission from the Cygnus complex
Meynet, G.; Knödlseder, J.; Diehl, R. +1 more
Context. The Cygnus region harbours a huge complex of massive stars at a distance of 1.0-2.0 kpc from us. About 170 O stars are distributed over several OB associations, among which the Cyg OB2 cluster is by far the most important with about 100-120 O stars. These massive stars inject large quantities of radioactive nuclei into the interstellar me…
Comparison between the luminosity functions of X-ray and [OIII] selected AGN
Georgantopoulos, I.; Akylas, A.
We investigate claims according to which the X-ray selection of AGN is not as efficient compared to that based on [OIII] selection because of the effects of X-ray absorption. We construct the predicted X-ray luminosity function both for all Seyferts as well as separately for Seyfert-1 and Seyfert-2 type galaxies, by combining the optical AGN [OIII…
The interface between the stellar wind and interstellar medium around R Cassiopeiae revealed by far-infrared imaging
Izumiura, H.; Stencel, R. E.; Matsunaga, N. +11 more
Aims: The circumstellar dust shells of intermediate initial-mass (~1 to 8 M⊙) evolved stars are generated by copious mass loss during the asymptotic giant branch phase. The density structure of their circumstellar shell is the direct evidence of mass loss processes, from which we can investigate the nature of mass loss.
Method…
The clusters Abell 222 and Abell 223: a multi-wavelength view
Bertin, E.; Adami, C.; Durret, F. +1 more
Context. The Abell 222 and 223 clusters are located at an average redshift z ~ 0.21 and are separated by 0.26 deg. Signatures of mergers have been previously found in these clusters, both in X-rays and at optical wavelengths, thus motivating our study. In X-rays, they are relatively bright, and Abell 223 shows a double structure. A filament has al…
XMM-Newton RGS observation of the warm absorber in Mrk 279
Kaastra, J. S.; Kriss, G. A.; Arav, N. +5 more
Context. The Seyfert 1 galaxy Mrk 279 was observed by XMM-Newton in November 2005 on three consecutive orbits, showing significant short-scale variability (average soft band variation in flux ~20%). The source is known to host a two-component warm absorber with distinct ionisation states from a previous Chandra observation.
Aims: We study the…
Spatially resolved detection of crystallized water ice in a T Tauri object
Wolf, S.; Schegerer, A. A.
Aims: We search for frozen water and its processing around young stellar objects (YSOs of class I/II). We try to detect potential, regional differences in water ice evolution within YSOs, which is relevant to understanding the chemical structure of the progenitors of protoplanetary systems and the evolution of solid materials. Water plays an …
Multi-frequency study of Local Group supernova remnants. The curious case of the Large Magellanic Cloud SNR J0528-6714
Pietsch, W.; Haberl, F.; Filipović, M. D. +3 more
Context. The SNRs known in the Local Group show a variety of morphological structures that are relatively uncorrelated in the different wavelength bands. This variety is probably caused by the different conditions in the surrounding medium with which the remnant interacts.
Aims: Recent ATCA, XMM-Newton and MCELS observations of the Magellanic…
Source counts at 15 microns from the AKARI NEP survey
Lee, H. M.; White, G. J.; Serjeant, S. +11 more
We present galaxy counts at 15 microns using the Japanese AKARI satelitte's NEP-deep and NEP-wide legacy surveys at the north ecliptic pole. The total number of sources detected are approximately 6700 and 10 700 down to limiting fluxes of 117 and 250 microJy (5 sigma) for the NEP-deep and NEP-wide survey respectively. We construct the Euclidean no…
Herschel deep far-infrared counts through Abell 2218 cluster-lens
Kneib, J. -P.; Berta, S.; Magnelli, B. +35 more
Gravitational lensing by massive galaxy clusters allows study of the population of intrinsically faint infrared galaxies that lie below the sensitivity and confusion limits of current infrared and submillimeter telescopes. We present ultra-deep PACS 100 and 160 µm observations toward the cluster lens Abell 2218 to penetrate the Herschel conf…
HIFI observations of warm gas in DR21: Shock versus radiative heating
Boulanger, F.; France, K.; Teyssier, D. +35 more
Context. The molecular gas in the DR21 massive star formation region is known to be affected by the strong UV field from the central star cluster and by a fast outflow creating a bright shock. The relative contribution of both heating mechanisms is the matter of a long debate.
Aims: By better sampling the excitation ladder of various tracers …