Search Publications
A Challenging Solar Eruptive Event of 18 November 2003 and the Causes of the 20 November Geomagnetic Superstorm. I. Unusual History of an Eruptive Filament
Temmer, M.; Grechnev, V. V.; Chertok, I. M. +4 more
This is the first of four companion papers, which comprehensively analyze a complex eruptive event of 18 November 2003 in active region (AR) 10501 and the causes of the largest Solar Cycle 23 geomagnetic storm on 20 November 2003. Analysis of a complete data set, not considered before, reveals a chain of eruptions to which hard X-ray and microwave…
Intermittent Dust Mass Loss from Activated Asteroid P/2013 P5 (PANSTARRS)
Moreno, F.; Licandro, J.; Cabrera-Lavers, A. +2 more
We present observations and models of the dust environment of activated asteroid P/2013 P5 (PANSTARRS). The object displayed a complex morphology during the observations, with the presence of multiple tails. We combined our own observations, all made with instrumentation attached to the 10.4 m Gran Telescopio Canarias on La Palma, with previously …
Searches for HCl and HF in comets 103P/Hartley 2 and C/2009 P1 (Garradd) with the Herschel Space Observatory
Küppers, M.; Hartogh, P.; de Graauw, T. +20 more
Context. Hydrogen chloride (HCl) and hydrogen fluoride (HF) are expected to be the main reservoirs of fluorine and chlorine over a wide range of conditions, wherever hydrogen is predominantly molecular. They are found to be strongly depleted in dense molecular clouds, suggesting freeze-out onto grains in such cold environments. We can then expect …
Horizontal flow fields observed in Hinode G-band images. IV. Statistical properties of the dynamical environment around pores
Verma, M.; Denker, C.
Context. Solar pores are penumbra-lacking magnetic features, that mark two important transitions in the spectrum of magnetohydrodynamic processes: (1) the magnetic field becomes sufficiently strong to suppress the convective energy transport and (2) at some critical point some pores develop a penumbra and become sunspots.
Aims: The purpose of…
Stratigraphy and mineralogy of Candor Mensa, West Candor Chasma, Mars: Insights into the geologic history of Valles Marineris
Hauber, E.; Rossi, A. P.; Flahaut, J. +2 more
Candor Mensa, an interior layered deposit (ILD) in Valles Marineris, Mars, consists of two stratigraphically distinct units, the lower of which comprises the bulk of the mensa. This lower unit is approximately 5 km thick and composed of parallel layers, 4 to 14 m in thickness and associated with monohydrated sulfates. The lower unit is disconforma…
X-Ray Absorption by the Warm-hot Intergalactic Medium in the Hercules Supercluster
Buote, David A.; Ren, Bin; Fang, Taotao
"Missing baryons," in the form of warm-hot intergalactic medium (WHIM), are expected to reside in cosmic filamentary structures that can be traced by signposts such as large-scale galaxy superstructures. The clear detection of an X-ray absorption line in the Sculptor Wall demonstrated the success of using galaxy superstructures as a signpost to se…
The Hard X-Ray Perspective on the Soft X-Ray Excess
Fabian, Andrew C.; Reynolds, Christopher S.; Zoghbi, Abderahmen +5 more
The X-ray spectra of many active galactic nuclei exhibit a "soft excess" below 1 keV, whose physical origin remains unclear. Diverse models have been suggested to account for it, including ionized reflection of X-rays from the inner part of the accretion disk, ionized winds/absorbers, and Comptonization. The ionized reflection model suggests a nat…
Observations and analysis of phase scintillation of spacecraft signal on the interplanetary plasma
Bocanegra-Bahamón, T. M.; Molera Calvés, G.; Duev, D. A. +13 more
Aims: The phase scintillation of the European Space Agency's Venus Express (VEX) spacecraft telemetry signal was observed at X-band (λ = 3.6 cm) with a number of radio telescopes of the European Very Long Baseline Interferometry (VLBI) Network in the period 2009-2013.
Methods: We found a phase fluctuation spectrum along the Venus orbit w…
Multifrequency study of a new Fe-rich supernova remnant in the Large Magellanic Cloud, MCSNR J0508-6902
Haberl, F.; Filipović, M. D.; Ehle, M. +15 more
We present a detailed radio, X-ray and optical study of a newly discovered Large Magellanic Cloud (LMC) supernova remnant (SNR) which we denote as MCSNR J0508-6902. Observations from the Australia Telescope Compact Array (ATCA) and the XMM-Newton X-ray observatory are complemented by deep Hα images and Anglo-Australian Telescope AAOmega spectrosco…
The globular cluster system of NGC 1316. III. Kinematic complexity
Hilker, M.; Gómez, M.; Dirsch, B. +3 more
Context. The merger remnant NGC 1316 (Fornax A) is one of the most important objects regarding the investigation of and thus an important object to study merger-related processes. A recent photometric study used globular clusters in NGC 1316 to constrain its star formation history, but without the knowledge of individual radial velocities. The kin…