Search Publications
The impact of improved estimates of radio star astrometric models on the alignment of the Gaia bright reference frame to ICRF3
Lestrade, Jean-François; Xu, Ming H.; Anderson, James M. +12 more
Aims. We investigated the residual orientation offset and spin between the bright (G ≤ 13 mag) frame of the Gaia Early Data Release 3 (Gaia EDR3) and the third realization of the International Celestial Reference Frame (ICRF3). For this purpose, six rotation parameters (orientation offset and its time derivative, the spin), as well as corrections …
Molecular line polarisation from the circumstellar envelopes of asymptotic giant branch stars
Velilla-Prieto, L.; Vlemmings, W. H. T.; Lankhaar, B.
Context. Polarisation observations of masers in the circumstellar envelopes (CSEs) around asymptotic giant branch (AGB) stars have revealed strong magnetic fields. However, masers probe only specific lines of sight through the CSE. Non-masing molecular line polarisation observations can more directly reveal the large-scale magnetic field morpholog…
An all-sky catalogue of stellar reddening values
Paunzen, E.; Prišegen, M.; Faltová, N. +1 more
Context. When observing astronomical objects, we have to deal with extinction (i.e. the absorption and scattering of the emitted radiation by dust and gas between the source and the observer). Interstellar extinction depends on the location of the object and the wavelength. The different extinction laws describing these effects are difficult to es…
CLASH-VLT: Galaxy cluster MACS J0329–0211 and its surroundings using galaxies as kinematic tracers
Demarco, R.; Grillo, C.; Tozzi, P. +9 more
Context. The study of substructure is an important step in determining how galaxy clusters form. Aims. We aim to gain new insights into the controversial dynamical status of MACS J0329–0211 (MACS0329), a massive cluster at z = 0.4503 ± 0.0003, through a new analysis using a large sample of member galaxies as kinematic tracers. Methods. Our analysi…
Supervised star, galaxy, and QSO classification with sharpened dimensionality reduction
Trager, S. C.; Lourens, M. A. A.; Kim, Y. +2 more
Aims. We explored the use of broadband colors to classify stars, galaxies, and quasi-stellar objects (QSOs). Specifically, we applied sharpened dimensionality reduction (SDR)-aided classification to this problem, with the aim of enhancing cluster separation in the projections of high-dimensional data clusters to allow for better classification per…
Radial properties of dust in galaxies: Comparison between observations and isolated galaxy simulations
De Looze, I.; Baes, M.; Palla, M. +8 more
We study the importance of several processes that influence the evolution of dust and its grain size distribution on spatially resolved scales in nearby galaxies. Here, we compiled several multi-wavelength observations for the nearby galaxies NGC 628 (M74), NGC 5457 (M101), NGC 598 (M33), and NGC 300. We applied spatially resolved spectral energy …
Novel scaling laws to derive spatially resolved flare and CME parameters from sun-as-a-star observables
Mohan, Atul; Akiyama, Sachiko; Gopalswamy, Natchimuthuk +1 more
Coronal mass ejections (CMEs) are often associated with X-ray (SXR) flares powered by magnetic reconnection in the low corona, while the CME shocks in the upper corona and interplanetary (IP) space accelerate electrons often producing the type II radio bursts. The CME and the reconnection event are part of the same energy release process as highli…
Unveiling the origin of XMM-Newton soft proton flares: II. Systematics in the proton spectral analysis
Cappi, M.; Molendi, S.; Gastaldello, F. +7 more
Context. Low-energy (< 300 keV) protons entering the field of view of the XMM-Newton telescope scatter with the X-ray mirror surface and might reach the X-ray detectors on the focal plane. They manifest in the form of a sudden increase in the rates, usually referred to as soft proton flares. By knowing the conversion factor between the soft pro…
Archives of Photographic PLates for Astronomical USE (APPLAUSE). Digitisation of astronomical plates and their integration into the International Virtual Observatory
Enke, Harry; Heber, Ulrich; Tuvikene, Taavi +2 more
Aims: The Archives of Photographic PLates for Astronomical USE (APPLAUSE) project is aimed at digitising astronomical photographic plates from three major German plate collections, making them accessible through integration into the International Virtual Observatory (IVO).
Methods: Photographic plates and related materials (logbooks, env…
Whistler-mode waves in the tail of Mercury's magnetosphere: A numerical study
Henri, Pierre; Lavorenti, Federico; Califano, Francesco +1 more
Context. Mercury presents a highly dynamic, small magnetosphere in which magnetic reconnection plays a fundamental role. Aim. We aim to model the global characteristics of magnetic reconnection in the Hermean environment. In particular, we focus on waves observed during the third BepiColombo flyby. Method. In this work, we used two fully kinetic t…