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Multiwavelength campaign on Mrk 509. X. Lower limit on the distance of the absorber from HST COS and STIS spectroscopy
Kaastra, J. S.; Kriss, G. A.; Arav, N. +15 more
Aims: Active galactic nuclei (AGN) often show evidence of photoionized outflows. A major uncertainty in models for these outflows is the distance (R) to the gas from the central black hole. In this paper we use the HST/COS data from a massive multi-wavelength monitoring campaign on the bright Seyfert I galaxy Mrk 509, in combination with arch…
Warm H2O and OH in the disk around the Herbig star HD 163296
Fedele, D.; Henning, Th.; van Dishoeck, E. F. +5 more
We present observations of far-infrared (50-200 µm) OH and H2O emission of the disk around the Herbig Ae star HD 163296 obtained with Herschel/PACS in the context of the DIGIT key program. In addition to strong [O i] emission, a number of OH doublets and a few weak highly excited lines of H2O are detected. The presence …
Atomic data for astrophysics: Fe xii soft X-ray lines
Mason, H. E.; Del Zanna, G.; Storey, P. J. +1 more
We present new large-scale R-matrix (up to n = 4) and distorted-wave (DW, up to n = 6) scattering calculations for electron collisional excitation of Fe xii. The first aim is to provide accurate atomic data for the soft X-rays, where strong decays from the n = 4 levels are present. As found in previous work on Fe x, resonances attached to n = 4 le…
A cometary nucleus model taking into account all phase changes of water ice: amorphous, crystalline, and clathrate
Mousis, O.; Schmitt, B.; Fray, N. +2 more
Context. Current theories, models of cometary nuclei and of ice formation in the protoplanetary disk, and laboratory studies suggest that cometary materials could be formed of pure crystalline water ice, amorphous water ice, clathrate hydrate, or a mixture of these structures of water ice. However, current models of cometary nuclei consider only t…
Spectroscopic analysis of the two subgiant branches of the globular cluster NGC 1851
Bragaglia, A.; Geisler, D.; Villanova, S. +5 more
It has been found that globular clusters host multiple stellar populations. In particular, in NGC 1851 the subgiant branch (SGB) can be divided into two components and the distribution of stars along the horizontal branch (HB) is multimodal. Various authors have found that NGC 1851 possibly has a spread in [Fe/H], but the relation between this spr…
Physical properties of OSIRIS-REx target asteroid (101955) 1999 RQ36. Derived from Herschel, VLT/ VISIR, and Spitzer observations
Altieri, B.; Küppers, M.; Pál, A. +6 more
In September 2011, the Herschel Space Observatory performed an observation campaign with the PACS photometer observing the asteroid
An insight in the surroundings of HR 4796
Ehrenreich, D.; Milli, J.; Lacour, S. +8 more
Context. HR 4796 is a young, early A-type star harboring a well structured debris disk, shaped as a ring with sharp inner edges. The inner edge might be shaped by a yet unseen planet inside the ring; the outer one is not well understood. The star forms together with the M-type star HR 4796B, a binary system, with a projected separation of ≃ 560 AU…
Coronal hole boundaries evolution at small scales. III. EIS and SUMER views
Doyle, J. G.; Madjarska, M. S.; Huang, Z. +1 more
Context. We report on the plasma properties of small-scale transient events identified in the quiet Sun, coronal holes and their boundaries.
Aims: We aim at deriving the physical characteristics of events that were identified as small-scale transient brightenings in XRT images.
Methods: We used spectroscopic co-observations from SUMER/So…
Detecting and modelling the magnetic field of the β Cephei star V 2052 Ophiuchi
Thizy, O.; Frémat, Y.; Neiner, C. +5 more
Aims: Following the indirect detection of a magnetic field in the β Cephei star
The interplanetary magnetic structure that guides solar relativistic particles
Klein, K. -L.; Démoulin, P.; Dasso, S. +1 more
Context. Relating in-situ measurements of relativistic solar particles to their parent activity in the corona requires understanding the magnetic structures that guide them from their acceleration site to the Earth. Relativistic particle events are observed at times of high solar activity, when transient magnetic structures such as interplanetary …