Search Publications
The spatial clustering of mid-IR selected star forming galaxies at z ~ 1 in the GOODS fields
Daddi, E.; Elbaz, D.; Stern, D. +6 more
We present the first spatial clustering measurements of z∼1, 24 µm-selected, star forming galaxies in the Great Observatories Origins Deep Survey (GOODS). The sample under investigation includes 495 objects in GOODS-South and 811 objects in GOODS-North selected down to flux densities of f24>20 µJy and z_AB<23.5 mag, fo…
The gaseous atmosphere of M 87 seen with XMM-Newton
Finoguenov, A.; Böhringer, H.; Simionescu, A. +1 more
Aims:M 87 is a key object whose study can reveal the complex phenomena in cooling cores. We use a deep XMM-Newton observation of M 87 to produce detailed temperature, pressure and entropy maps in order to analyze the physical processes of cooling cores and of their heating mechanisms.
Methods: We employed both broad-band fitting and full spect…
Modelling dications in the diurnal ionosphere of Venus
Witasse, O.; Gronoff, G.; Lilensten, J. +4 more
Context: Previous studies have shown that doubly-charged positive ions, including molecular ions, can have detectable densities in the ionospheres of Mars, Titan, and the Earth.
Aims: In the present paper, we continue our approach by modelling the Venusian ionosphere. The neutral atmosphere of Venus has a similar composition to the ones encoun…
On the co-existence of chemically peculiar Bp stars, slowly pulsating B stars and constant B stars in the same part of the HR diagram
Aerts, C.; Briquet, M.; De Cat, P. +3 more
Aims: In order to better model massive B-type stars, we need to understand the physical processes taking place in slowly pulsating B (SPB) stars, chemically peculiar Bp stars, and non-pulsating normal B stars co-existing in the same part of the H-R diagram.
Methods: We carry out a comparative study between samples of confirmed and well-studied…
Solar abundances of oxygen and neon derived from solar wind observations
Bochsler, P.
Context: Recently, a revision of the solar abundances of C, N, and O to substantially lower values has led to a controversy on solar opacities in the solar standard model and to the suggestion to revise the solar abundance of neon upward by as much as a factor of 1.6 leading to enhanced solar neon/oxygen abundance ratios by a factor of 3. Neon and…
XMM-Newton observation of the NLS1 galaxy Ark 564. I. Spectral analysis of the time-average spectrum
McHardy, I.; Papadakis, I. E.; Page, M. J. +2 more
Context: We present the results from the spectral analysis of the time-average spectrum of the Narrow Line Seyfert 1 (NLS1) galaxy Ark 564 from a ~100 ks XMM-Newton observation.
Aims: Our aim is to characterize accurately the shape of the time-average, X-ray continuum spectrum of the source and search for any emission and/or absorption feature…
Diffuse gamma-ray emission from the Galactic center - a multiple energy injection model
Cheng, K. S.; Chernyshov, D. O.; Dogiel, V. A.
We suggest that the energy source of the observed diffuse gamma-ray emission from the direction of the Galactic center is the Galactic black hole Sgr A*, which becomes active when a star is captured at a rate of ~10-5 yr-1. Subsequently the star is tidally disrupted and its matter is accreted into the black hole. During the a…
Discovery of a new M 32-like "Compact Elliptical" galaxy in the halo of the Abell 496 cD galaxy
Chilingarian, I.; Adami, C.; Chemin, L. +4 more
Aims:"Compact ellipticals" are so rare that a search for M 32 analogs is needed to ensure the very existence of this class.
Methods: We report here the discovery of A496cE, a M 32 twin in the cluster Abell 496, located in the halo of the central cD.
Results: Based on CFHT and HST imaging we show that the light profile of A496cE requires a …
Three clusters of the SMC from ACS/WFC HST archive data: NGC 265, K 29 and NGC 290 and their field population
Chiosi, E.; Vallenari, A.
Aims:We determine the age, metallicity and initial mass function of three clusters, namely
Methods: We make use of ACS/WFC HST arc…
Unveiling the broad band X-ray continuum and iron line complex in Mrk 841
Maraschi, L.; Nandra, K.; Ponti, G. +7 more
Context:
Aims: