Search Publications
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…
Molecular gas mass functions of normal star-forming galaxies since z ~ 3
Berta, S.; Magnelli, B.; Nordon, R. +7 more
We used deep far-infrared data from the PEP/GOODS-Herschel surveys and restframe ultraviolet photometry to study the evolution of the molecular gas mass function of normal star-forming galaxies. Computing the molecular gas mass, Mmol, by scaling star formation rates through depletion timescales, or combining infrared (IR) luminosity and…
Unveiling shocks in planetary nebulae
Toalá, Jesús A.; Guerrero, Martín A.; Miranda, Luis F. +4 more
The propagation of a shock wave into a medium is expected to heat the material beyond the shock, producing noticeable effects in intensity line ratios such as [O iii]/Hα. To investigate the occurrence of shocks in planetary nebulae (PNe), we have used all narrow-band [O iii] and Hα images of PNe available in the HST archive to build their [O iii]/…
Pillars and globules at the edges of H ii regions. Confronting Herschel observations and numerical simulations
Hill, T.; White, G. J.; Roussel, H. +24 more
Context. Herschel far-infrared imaging observations have revealed the density structure of the interface between H ii regions and molecular clouds in great detail. In particular, pillars and globules are present in many high-mass star-forming regions, such as the Eagle nebula (M 16) and the Rosette molecular cloud, and understanding their origin w…
OH/IR stars and their superwinds as observed by the Herschel Space Observatory
Waters, L. B. F. M.; Teyssier, D.; Justtanont, K. +4 more
Aims: In order to study the history of mass loss in extreme OH/IR stars, we observed a number of these objects using CO as a tracer of the density and temperature structure of their circumstellar envelopes.
Methods: Combining CO observations from the Herschel Space Observatory with those from the ground, we trace mass loss rates as a fun…