Search Publications
A large population of ultra-compact dwarf galaxies in the Hydra I cluster
Hilker, M.; Georgiev, I. Y.; Richtler, T. +3 more
Aims: We performed a large spectroscopic survey of compact, unresolved objects in the core of the Hydra I galaxy cluster (Abell 1060), with the aim of identifying ultra-compact dwarf galaxies (UCDs) and investigating the properties of the globular cluster (GC) system around the central cD galaxy NGC 3311.
Methods: We obtained VIMOS mediu…
Integral field spectroscopy of nitrogen overabundant blue compact dwarf galaxies
Kehrig, C.; Pérez-Montero, E.; Vílchez, J. M. +6 more
Context. The oxygen and nitrogen-to-oxygen abundances relation is characterized by a plateau around log(N/O) = -1.6 at metallicities lower than 12+log(O/H) ~ 8.25. However, there is a subset of blue compact dwarf galaxies (BCDs) with unexpectedly high N/O values.
Aims: We want to study the spatial distribution of the physical properties and o…
Galactic cold cores. II. Herschel study of the extended dust emission around the first Planck detections
Abergel, A.; Bernard, J. -P.; Dickinson, C. +15 more
Context. Within the project Galacticcoldcores we are carrying out Herschel photometric observations of cold interstellar clouds detected with the Planck satellite. The three fields observed as part of the Herschel science demonstration phase (SDP) provided the first glimpse into the nature of these sources. The aim of the project is to derive the …
Excitation of H2 in photodissociation regions as seen by Spitzer
Boulanger, F.; Abergel, A.; Le Bourlot, J. +5 more
Aims: We present spectroscopic observations obtained with the infrared Spitzer Space Telescope, which provide insight into the H2 physics and gas energetics in photodissociation regions (PDRs) of low to moderate far-ultraviolet (FUV) fields and densities.
Methods: We analyze data on six well known Galactic PDRs (L1721, Califor…
Identifying XMM-Newton observations affected by solar wind charge exchange - Part II
Read, A. M.; Carter, J. A.; Sembay, S.
Aims: We wished to analyse a sample of observations from the XMM-Newton Science Archive to search for evidence of exospheric solar wind charge exchange (SWCX) emission.
Methods: We analysed 3012 observations up to and including revolution 1773. The method employed extends from that of the previously published paper by these authors on th…
Photochemistry of polycyclic aromatic hydrocarbons in cosmic water ice. I. Mid-IR spectroscopy and photoproducts
Allamandola, L. J.; Bouwman, J.; Linnartz, H. +1 more
Context. Polycyclic aromatic hydrocarbons (PAHs) are known to be abundantly present in photon-dominated regions (PDRs), as evidenced by their ubiquitous mid-IR emission bands. Towards dense clouds, however, their IR emission bands are strongly suppressed. It is here where molecules are known to reside on very cold grains (T ≤ 30 K) in the form of …
OH emission from warm and dense gas in the Orion Bar PDR
Le Bourlot, J.; Contursi, A.; Bergin, E. A. +7 more
As part of a far-infrared (FIR) spectral scan with Herschel/PACS, we present the first detection of the hydroxyl radical (OH) towards the Orion Bar photodissociation region (PDR). Five OH (X 2Π; ν = 0) rotational Λ-doublets involving energy levels out to Eu/k ~ 511 K have been detected (at ~65, ~79, ~84, ~119 and ~163 µ…
Observation of H2O in a strongly lensed Herschel-ATLAS source at z = 2.3
Smail, I.; Omont, A.; Clements, D. L. +54 more
The Herschel survey, H-ATLAS, with its large areal coverage, has recently discovered a number of bright, strongly lensed high-z submillimeter galaxies. The strong magnification makes it possible to study molecular species other than CO, which are otherwise difficult to observe in high-z galaxies. Among the lensed galaxies already identified by H-A…
Dynamical evolution of a magnetic cloud from the Sun to 5.4 AU
Mandrini, C. H.; Gulisano, A. M.; Démoulin, P. +2 more
Context. Significant quantities of magnetized plasma are transported from the Sun to the interstellar medium via interplanetary coronal mass ejections (ICMEs). Magnetic clouds (MCs) are a particular subset of ICMEs, forming large-scale magnetic flux ropes. Their evolution in the solar wind is complex and mainly determined by their own magnetic for…
X-ray monitoring of classical novae in the central region of M 31. II. Autumn and winter 2007/2008 and 2008/2009
Della Valle, M.; Pietsch, W.; Haberl, F. +7 more
Context. Classical novae (CNe) represent the major class of supersoft X-ray sources (SSSs) in the central region of the galaxy M 31.
Aims: We performed a dedicated monitoring of the M 31 central region with XMM-Newton and Chandra between Nov. 2007 and Feb. 2008 and between Nov. 2008 and Feb. 2009, respectively, to find SSS counterparts of CNe…