Search Publications
Modeling of comet water production: I. Sensitivity to macro- and micro-model parameters
Küppers, M.; Hartogh, P.; Rezac, L. +3 more
Aims. This study investigates the impact of microscopic and macroscopic cometary surface properties on water production variations with heliocentric distance, focusing on dust layer thickness, grain size, nucleus shape, and spin axis orientation. Methods. We employed a two-layer thermophysical model to calculate effective gas production, incorpora…
Electron and proton peak intensities as observed by a five-spacecraft fleet in solar cycle 25
Vainio, R.; Farwa, G. U.; Dresing, N. +9 more
Context. Solar energetic particle (SEP) events are related to solar flares and fast coronal mass ejections (CMEs). In the case of large events, which are typically associated with both a strong flare and a fast CME driving a shock front, identification of the dominant SEP acceleration mechanism is challenging. Aims. Using novel spacecraft observat…
The environments of radio galaxies and quasars in LoTSS data release 2
van Weeren, R. J.; Rottgering, H. J. A.; Pan, T. +4 more
Aims. The orientation-based unification scheme of radio-loud active galactic nuclei (AGNs) asserts that radio galaxies and quasars are essentially the same type of object, but viewed from different angles. To test this unification model, we compared the environments of radio galaxies and quasars, which would reveal similar properties when an accur…
Connecting energetic electrons at the Sun and in the heliosphere through X-ray and radio diagnostics
Maksimovic, Milan; Vilmer, Nicole; Krupar, Vratislav +2 more
Context. Solar flares release huge amounts of energy, a considerable part of which is channeled into particle acceleration in the lower corona. Hard X-ray (HXR) emissions are used to diagnose the accelerated electrons that bombard the chromosphere, while type III radio bursts result from energetic electron beams propagating through the corona and …
Background exoplanet candidates in the original Kepler field
Szabó, R.; Bienias, J.
Context. During the primary Kepler mission, between 2009 and 2013, about 150 000 pre-selected targets were observed with a 29.42 minute-long cadence. However, a survey of background stars that fall within the field of view of the downloaded apertures of the primary targets has revealed a number of interesting objects. In previous papers we have pr…
An X-ray study of changing-look active galactic nuclei
Titarchuk, Lev; Seifina, Elena; Mishin, Egor
A significant number of changing-look active galactic nuclei (CL AGNs) have been identified to date. In this work, we study what happens to the X-ray spectrum during CL events. We use the example of the nearby CL Seyfert named NGC 1566, which has been observed by Swift, NuSTAR, XMM-Newton, and Suzaku. We applied the Comptonization model to describ…
Thermal environment and erosion of comet 67P/Churyumov-Gerasimenko
Jorda, L.; Keller, H. U.; Groussin, O. +11 more
Aims. This paper focuses on how insolation affects the nucleus of comet 67P/Churyumov-Gerasimenko over its current orbit. We aim to better understand the thermal environment of the nucleus, in particular its surface temperature variations, erosion, relationship with topography, and how insolation affects the interior temperature for the location o…
Surface brightness-colour relations of dwarf stars from detached eclipsing binaries: II. Extension of the calibrating sample
Smolec, R.; Kervella, P.; Maxted, P. F. L. +21 more
Aims. Surface brightness-colour relations (SBCRs) are useful tools for predicting the angular diameters of stars. They offer the possibility to calculate precise spectrophotometric distances based on the eclipsing binary method or the Baade–Wesselink method. Double-lined detached eclipsing binary stars (SB2 DEBs), with precisely known trigonometri…
Spectral properties of the neutron star low-mass X-ray binaries 4U 1636–53, XTE J1739–285, and MAXI J1816–195
García, Federico; Zhang, Guobao; Lyu, Ming +2 more
We investigated simultaneous NICER plus NuSTAR observations of the three neutron star low-mass X-ray binaries 4U 1636–53, XTE J1739–285, and MAXI J1816–195 using the latest reflection models. The seed photons in our models that are fed into the corona originated from either the neutron star (NS) or the accretion disk. We found that for the sources…
The aluminium-26 distribution in a cosmological simulation of a Milky Way-type Galaxy
Yagüe López, A.; Lugaro, M.; Wehmeyer, B. +1 more
Context. The 1.8 MeV γ-rays corresponding to the decay of the radioactive isotope 26Al (with a half-life of 0.72 Myr ) have been observed by the SPI detector on the INTEGRAL spacecraft and extensively used as a tracer of star formation and current nucleosynthetic activity in the Milky Way Galaxy. Further information is encoded in the ob…