Search Publications
The December 2015 re-brightening of V404 Cygni. Variable absorption from the accretion disc outflow
Motta, S. E.; Sánchez-Fernández, C.; Kuulkers, E. +1 more
In December 2015 the black hole binary V404 Cyg underwent a secondary outburst after the main June 2015 event. We monitored this re-brightening with the INTEGRAL and Swift satellites, and in this paper we report the results of the time-resolved spectral analysis of these data. The December outburst shared several characteristics with the June even…
Herschel spectral-line mapping of the HH211 protostellar system
Güdel, Manuel; Ray, Tom; Dionatos, Odysseas
Context. Mid- and far-infrared observations of the environment around embedded protostars reveal a plethora of high-excitation molecular and atomic emission lines. A number of different mechanisms for the origin of these lines have been proposed, including shocks induced by protostellar jets and radiation by the embedded protostar interacting with…
TOPoS. V. Abundance ratios in a sample of very metal-poor turn-off stars
Steffen, M.; Ludwig, H. -G.; Bonifacio, P. +12 more
Context. Extremely metal-poor stars are keys to understand the early evolution of our Galaxy. The ESO large programme TOPoS has been tailored to analyse a new set of metal-poor turn-off stars, whereas most of the previously known extremely metal-poor stars are giant stars.
Aims: Sixty five turn-off stars (preselected from SDSS spectra) have b…
Early phases in the stellar and substellar formation and evolution. Infrared and submillimeter data in the Barnard 30 dark cloud
Eiroa, C.; Bayo, A.; Huélamo, N. +10 more
Aims: The early evolutionary stage of brown dwarfs (BDs) is not very well characterized, especially during the embedded phase. Our goal is to gain insight into the dominant formation mechanism of very low-mass objects and BDs.
Methods: We have conducted deep observations at 870 µm obtained with the LABOCA bolometer at the APEX tele…
Brightening and Darkening of the Extended Solar Corona during the Superflares of September 2017
West, Matthew J.; Podladchikova, O.; D'Huys, Elke +3 more
On 2017 September 6 and 10, the strongest X9.3 and X8.2 flares of the decade occurred in the active region NOAA Active Region 12673. During these flares, the Sun Watcher with Active Pixels and Image Processing (SWAP) telescope on board the Project for Onboard Autonomy 2 (PROBA2) satellite registered the unusual alternate brightening and darkening …
Extraplanar H II Regions in Spiral Galaxies. II. In Situ Star Formation in the Interstellar Thick Disk of NGC 4013
Savage, Blair D.; Lehner, Nicolas; Howk, J. Christopher +3 more
We present observations of an Hα-emitting knot in the thick disk of NGC 4013, demonstrating it is an H II region surrounding a cluster of young hot stars z = 860 pc above the plane of this edge-on spiral galaxy. With LBT/MODS spectroscopy we show that this H II region has an Hα luminosity ∼4-7 times that of the Orion nebula, with an implied ionizi…
Resonant Scattering Effect on the Soft X-Ray Line Emission from the Hot Interstellar Medium. I. Galactic Bulges
Wang, Q. Daniel; Chen, Yang; Zhang, Shuinai +2 more
Diffuse soft X-ray line emission is commonly used to trace the thermal and chemical properties of the hot interstellar medium, as well as its content, in nearby galaxies. Although resonant-line scattering complicates the interpretation of the emission, it also offers an opportunity to measure the kinematics of the medium. We have implemented a dir…
Addressing some critical aspects of the BepiColombo MORE relativity experiment
Schettino, Giulia; Serra, Daniele; Tommei, Giacomo +1 more
The Mercury Orbiter Radio science Experiment (MORE) is one of the experiments on-board the ESA/JAXA BepiColombo mission to Mercury, to be launched in October 2018. Thanks to full on-board and on-ground instrumentation performing very precise tracking from the Earth, MORE will have the chance to determine with very high accuracy the Mercury-centric…
Saturn's Innermost Radiation Belt Throughout and Inward of the D-Ring
Krupp, N.; Roussos, E.; Mitchell, D. G. +6 more
Cassini discovered Saturn's innermost radiation belt during the end of its mission. The belt is populated with relativistic protons, probably up to the trapping limit of ≈20 GeV. It extends from Saturn's dense atmosphere into and throughout the D-ring. The A-C rings separate this belt entirely from the previously known radiation belts, suggesting …
Equatorial Evolution of the Fast Magnetosonic Mode in the Source Region: Observation-Simulation Comparison of the Preferential Propagation Direction
Boardsen, Scott A.; Liu, Kaijun; Denton, Richard E. +1 more
Recent analysis of an event observed by the Van Allen Probes in the source region outside the plasmapause has shown that fast magnetosonic waves (also referred to as equatorial noise) propagate preferentially in the azimuthal direction, implying that wave amplification should occur during azimuthal propagation. To demonstrate this, we carry out 2-…