Search Publications
Inaccuracies and biases of the Gaussian size deconvolution for extracted sources and filaments
Men'shchikov, A.
A simple Gaussian size deconvolution method is routinely used to remove the blur of observed images caused by insufficient angular resolutions of existing telescopes, thereby to estimate the physical sizes of extracted sources and filaments. To ensure that the physical conclusions derived from observations are correct, it is necessary to know the …
Toward more accurate RR Lyrae metallicities
Kovacs, Geza; Jurcsik, Johanna
By using a large sample of fundamental mode RR Lyrae stars with published spectroscopic iron abundances and gravities, we point out the importance of correcting these abundances by using more accurate temporal gravities. For the 197 stars with multiple spectra, overall we find [Fe/H] standard deviations of 0.167 (as published), 0.145 (shifted by d…
Accelerated particle beams in a 3D simulation of the quiet Sun. Lower atmospheric spectral diagnostics
Rouppe van der Voort, L.; Carlsson, M.; Gudiksen, B. V. +2 more
Context. Nanoflare heating through small-scale magnetic reconnection events is one of the prime candidates to explain heating of the solar corona. However, direct signatures of nanoflares are difficult to determine, and unambiguous observational evidence is still lacking. Numerical models that include accelerated electrons and can reproduce flarin…
Polarimetry of the potential binary supermassive black hole system in J1430+2303
Antonucci, R.; Blinov, D.; Liodakis, I. +6 more
Context. The growth of supermassive black holes (SMBHs) through merging has long been predicted but its detection remains elusive. However, a promising target has been discovered in the Seyfert-1 galaxy J1430+2303, where two SMBHs may be about to merge.
Aims: If a binary system truly lies at the center of J1430+2303, the usual symmetry expect…
Magnetic reconnection as an erosion mechanism for magnetic switchbacks
Horbury, T. S.; Louarn, P.; Owen, C. J. +3 more
Context. Magnetic switchbacks are localised polarity reversals in the radial component of the heliospheric magnetic field. Observations from Parker Solar Probe (PSP) have shown that they are a prevalent feature of the near-Sun solar wind. However, observations of switchbacks at 1 au and beyond are less frequent, suggesting that these structures ev…
Planetary system architectures with low-mass inner planets. Direct imaging exploration of mature systems beyond 1 au
Henning, Th.; Babusiaux, C.; Messina, S. +20 more
Context. The discovery of planets orbiting at less than 1 au from their host star and less massive than Saturn in various exoplanetary systems revolutionized our theories of planetary formation. The fundamental question is whether these close-in low-mass planets could have formed in the inner disk interior to 1 au, or whether they formed further o…
Exploring the internal rotation of the extremely low-mass He-core white dwarf GD 278 with TESS asteroseismology
Córsico, Alejandro H.; Hermes, J. J.; Althaus, Leandro G. +2 more
Context. The advent of high-quality space-based photometry, brought about by missions such as Kepler/K2 and TESS, makes it possible to unveil the fundamental parameters and properties of the interiors of white dwarf stars, particularly extremely low-mass white dwarfs, using the tools of asteroseismology.
Aims: We present an exploration of the…
Intensity contrast of solar network and faculae close to the solar limb, observed from two vantage points
Schmidt, W.; Woch, J.; Solanki, S. K. +44 more
Context. The brightness of faculae and network depends on the angle at which they are observed and the magnetic flux density. Close to the limb, the assessment of this relationship has until now been hindered by the increasingly lower signal in magnetograms.
Aims: This preliminary study aims to highlight the potential of using simultaneous ob…
Beyond small-scale transients: A closer look at the diffuse quiet solar corona
Peter, H.; Chitta, L. P.; Solanki, S. K. +9 more
Aims: Within the quiet Sun corona imaged at 1 MK, much of the field of view consists of diffuse emission that appears to lack the spatial structuring that is so evident in coronal loops or bright points. Our aim is to determine if these diffuse regions are categorically different in terms of their intensity fluctuations and spatial configurat…
XMM-Newton observation of V1504 Cyg as a probe for the existence of an evaporated corona
Ness, J. -U.; Dobrotka, A.; Nucita, A. A. +1 more
Aims: We present an analysis of an XMM-Newton observation of the dwarf nova V1504 Cyg during the decline from an outburst. Our goal is to search for evidence of an evaporated X-ray corona. Such a corona can be understood as an optically thin and geometrically thick disc around the central part of an optically thick and geometrically thin disc…