Search Publications
Optical counterpart of HLX-1 during the 2010 outburst
Soria, Roberto; Kong, Albert K. H.; Gladstone, Jeanette C. +2 more
We studied the optical counterpart of the intermediate-mass black hole candidate HLX-1 in ESO 243-49. We used a set of Very Large Telescope imaging observations from 2010 November, integrated by Swift X-ray data from the same epoch. We measured standard Vega brightnesses U= 23.89 ± 0.18 mag, B= 25.19 ± 0.30 mag, V= 24.79 ± 0.34 mag and R= 24.71 ± …
Moderate-luminosity Growing Black Holes from 1.25 < z < 2.7: Varied Accretion in Disk-dominated Hosts
Urry, C. M.; Simmons, B. D.; Schawinski, K. +2 more
We compute black hole masses and bolometric luminosities for 57 active galactic nuclei (AGNs) in the redshift range 1.25 <= z <= 2.67, selected from the GOODS-South deep multi-wavelength survey field via their X-ray emission. We determine host galaxy morphological parameters by separating the galaxies from their central point sources in deep…
Observations of ICMEs and ICME-like Solar Wind Structures from 2007 - 2010 Using Near-Earth and STEREO Observations
Luhmann, J. G.; Russell, C. T.; Kilpua, E. K. J. +2 more
The generally low interplanetary magnetic field magnitude around the minimum between Solar Cycles 23 and 24 (SC 23/24 minimum) allows us to identify weak and small solar wind structures. We use observations from near-Earth and twin STEREO spacecraft to study solar wind conditions from January 2007 through December 2010. In addition to 84 clear int…
Geologic interpretation of the near-infrared images of the surface taken by the Venus Monitoring Camera, Venus Express
Scholten, F.; Roatsch, Th.; Fiethe, B. +9 more
We analyze night-time near-infrared (NIR) thermal emission images of the Venus surface obtained with the 1-µm channel of the Venus Monitoring Camera onboard Venus Express. Comparison with the results of the Magellan radar survey and the model NIR images of the Beta-Phoebe region show that the night-time VMC images provide reliable informatio…
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…
The tidal tails of 47 Tucanae
Lane, Richard R.; Küpper, Andreas H. W.; Heggie, Douglas C.
The Galactic globular cluster 47 Tucanae (47 Tuc) shows a rare increase in its velocity dispersion profile at large radii, indicative of energetic, yet bound, stars at large radii dominating the velocity dispersion and, potentially, of ongoing evaporation. Escaping stars will form tidal tails, as seen with several Galactic globular clusters; howev…
On the ionospheric source region of cold ion outflow
Fränz, M.; Wei, Y.; Daly, P. W. +8 more
Recent studies have shown that low energy ions constitute a significant part of the total ion population in the Earth's magnetosphere. In this study, we have used a comprehensive data set with measurements of cold (total energy less than 70 eV) ion velocity and density to determine their source. This data set is derived from Cluster satellite meas…
Mid-infrared Spectral Variability Atlas of Young Stellar Objects
Ábrahám, P.; Kóspál, Á.; Henning, Th. +6 more
Optical and near-infrared variability is a well-known property of young stellar objects. However, a growing number of recent studies claim that a considerable fraction of them also exhibit mid-infrared flux changes. With the aim of studying and interpreting variability on a decadal timescale, here we present a mid-infrared spectral atlas containin…
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…