Search Publications
Multiple stellar populations in Magellanic Cloud clusters. II. Evidence also in the young NGC 1844?
Anderson, J.; Milone, A. P.; Bedin, L. R. +4 more
We used Hubble Space Telescope observations to study the young cluster NGC 1844 in the Large Magellanic Cloud (LMC). We estimated the fraction and the mass-ratio distribution of photometric binaries and report that the main sequence presents an intrinsic breadth which cannot be explained only in terms of photometric errors, and is unlikely because…
Multiwavelength campaign on Mrk 509. XI. Reverberation of the Fe Kα line
Kaastra, J. S.; Kriss, G. A.; Arav, N. +17 more
Context. We report on a detailed study of the Fe K emission/absorption complex in the nearby, bright Seyfert 1 galaxy Mrk 509. The study is part of an extensive XMM-Newton monitoring consisting of 10 pointings (~60 ks each) about once every 4 days, and includes a reanalysis of previous XMM-Newton and Chandra observations.
Aims: We aim at unde…
Diffuse light in the young cluster of galaxies CL J1449+0856 at z = 2.07
Adami, C.; Durret, F.; Guennou, L. +1 more
Context. Cluster properties do not seem to be changing significantly during their mature evolution phase; for example, they do not seem to show any strong dynamical evolution at least up to z ~ 0.5, their galaxy red sequence is already in place at least up to z ~ 1.2, and their diffuse light content remains stable up to z ~ 0.8. The question is no…
The circumstellar environment and evolutionary state of the supergiant B[e] star Wd1-9
Negueruela, I.; Clark, J. S.; Ritchie, B. W.
Context. Historically, supergiant (sg)B[e] stars have been difficult to include in theoretical schemes for the evolution of massive OB stars.
Aims: The location of Wd1-9 within the coeval starburst cluster Westerlund 1 means that it may be placed into a proper evolutionary context and we therefore aim to utilise a comprehensive multiwavelengt…
Ram pressure and dusty red galaxies - key factors in the evolution of the multiple cluster system Abell 901/902
Gray, M. E.; Wolf, C.; Barden, M. +6 more
Aims: We present spectroscopic observations of 182 disk galaxies (96 in the cluster and 86 in the field environment) in the region of the Abell 901/902 multiple cluster system, which is located at a redshift of z ~ 0.165. We estimate dynamical parameters of the four subclusters and analyse the kinematics of spiral galaxies, searching for indi…
Discovery of very high energy γ-ray emission from the BL Lacertae object PKS 0301-243 with H.E.S.S.
Klochkov, D.; Santangelo, A.; Quirrenbach, A. +211 more
The active galactic nucleus
Variable pulse profiles of Hercules X-1 repeating with the same irregular 35 d clock as the turn-ons
Klochkov, D.; Wilms, J.; Staubert, R. +4 more
The accreting X-ray pulsar Her X-1 shows two types of long-term variations, both with periods of ~35 days: 1) turn-on cycles, a modulation of the flux, with a ten-day long main-on and a five-day long short-on, separated by two off-states, and 2) a systematic variation in the shape of the 1.24 s pulse profile. While there is general consensus that …
Electron density distribution and solar plasma correction of radio signals using MGS, MEX, and VEX spacecraft navigation data and its application to planetary ephemerides
Issautier, K.; Laskar, J.; Fienga, A. +3 more
The Mars Global Surveyor (MGS), Mars Express (MEX), and Venus Express (VEX) experienced several superior solar conjunctions. These conjunctions cause severe degradations of radio signals when the line of sight between the Earth and the spacecraft passes near to the solar corona region. The primary objective of this work is to deduce a solar corona…
Spatial distribution of small hydrocarbons in the neighborhood of the ultra compact HII region Monoceros R2
Le Bourlot, J.; Le Petit, F.; Ossenkopf, V. +14 more
Context. We study the chemistry of small hydrocarbons in the photon-dominated regions (PDRs) associated with the ultra-compact H ii region (UCH ii) Mon R2.
Aims: Our goal is to determine the variations in the abundance of small hydrocarbons in a high-UV irradiated PDR and investigate the chemistry of these species.
Methods: We present an…
Towards understanding the relation between the gas and the attenuation in galaxies at kpc scales
Ciesla, L.; Buat, V.; Boquien, M. +13 more
Context. Understanding the relation between the attenuation and the gas is fundamental for interpreting the appearance of galaxies. This can now be done down to a local scale in the local Universe, thanks to the high spatial resolution achievable from the far-ultraviolet (FUV) to the far-infrared (FIR). More importantly, this relation is also cruc…