Search Publications

Simultaneous X-ray and optical variability of M dwarfs observed with eROSITA and TESS
DOI: 10.1051/0004-6361/202449405 Bibcode: 2024A&A...688A..49J

Stelzer, B.; Magaudda, E.; Joseph, W. M. +1 more

Context. M-dwarf stars are the most numerous stars in the Galaxy, and are highly magnetically active. They exhibit bursts of radiation and matter, called flares and coronal mass ejections which have the potential to strongly affect the habitability of their planets.
Aims: We investigate variability through simultaneous optical and X-ray obser…

2024 Astronomy and Astrophysics
Gaia 2
Mg II h&k spectra of an enhanced network region simulated with the MURaM-ChE code: Results using 1.5D synthesis
DOI: 10.1051/0004-6361/202450788 Bibcode: 2024A&A...692A...6O

Solanki, S. K.; Leenaarts, J.; Cameron, R. +3 more

Context. The Mg II h&k lines are key diagnostics of the solar chromosphere. They are sensitive to the temperature, density, and nonthermal velocities in the chromosphere. The average Mg II h&k line profiles arising from previous 3D chromospheric simulations are too narrow compared to observations. Aims. We study the formation and properties of the…

2024 Astronomy and Astrophysics
IRIS 2
eRASSU J060839.5-704014: A double degenerate ultra-compact binary in the direction of the LMC
DOI: 10.1051/0004-6361/202347811 Bibcode: 2024A&A...683A..21M

Haberl, F.; Rau, A.; Vasilopoulos, G. +7 more

Context. During four all-sky surveys (eRASS1-4), eROSITA, the soft X-ray instrument aboard Spektrum-Roentgen-Gamma (SRG) detected a new supersoft X-ray source, eRASSU J060839.5−704014, in the direction of the Large Magellanic Cloud (LMC).
Aims: We arranged follow-up observations in the X-ray and optical wavelengths and further searched in arc…

2024 Astronomy and Astrophysics
Gaia XMM-Newton 2
Structure and dynamics of the Hermean magnetosphere revealed by electron observations from the Mercury electron analyzer after the first three Mercury flybys of BepiColombo
DOI: 10.1051/0004-6361/202449450 Bibcode: 2024A&A...687A.243R

André, N.; Fedorov, A.; Sauvaud, J. -A. +16 more

Context. The Mercury electron analyzer (MEA) obtained new electron observations during the first three Mercury flybys by BepiColombo on October 1, 2021 (MFB1), June 23 , 2022 (MFB2), and June 19, 2023 (MFB3). BepiColombo entered the dusk side magnetotail from the flank magnetosheath in the northern hemisphere, crossed the Mercury solar orbital equ…

2024 Astronomy and Astrophysics
BepiColombo 2
A combined LOFAR and XMM-Newton analysis of the disturbed cluster PSZ2G113.91-37.01
DOI: 10.1051/0004-6361/202346591 Bibcode: 2024A&A...683A...9C

Brunetti, G.; Rossetti, M.; Gastaldello, F. +10 more

In this work, we investigate the interplay between the X-ray and radio emission of the cluster PSZ2G113.91-37.01 (z = 0.371) using the high-quality XMM-Newton observations of the Cluster HEritage project with XMM-Newton - Mass Assembly and Thermodynamics at the Endpoint of structure formation (CHEX-MATE), and the images from the second data releas…

2024 Astronomy and Astrophysics
XMM-Newton 2
Spectral characterisation of the extinction properties of NGC 3603 using JWST NIRSpec
DOI: 10.1051/0004-6361/202348551 Bibcode: 2024A&A...688A.111R

De Marchi, Guido; Brandl, Bernhard; Rogers, Ciarán

Context. A necessary ingredient in understanding the star formation history of a young cluster is knowledge of the extinction towards the region. This has typically been done by making use of the colour-difference method with photometry, or similar methods utilising the colour-colour diagram. These approaches rely on adopting an extinction law wit…

2024 Astronomy and Astrophysics
Gaia eHST JWST 2
The X-ray binaries in M83: Will any of them form gravitational wave sources for LIGO-VIRGO-KAGRA?
DOI: 10.1051/0004-6361/202346880 Bibcode: 2024A&A...683A..85K

Kotko, I.; Belczynski, K.

There are 214 X-ray point sources (LX > 1035 erg s−1) identified as X-ray binaries (XRBs) in the nearby spiral galaxy M83. Since XRBs are powered by accretion onto a neutron star (NS) or a black hole (BH) from a companion or donor star, these systems are promising progenitors of merging double compact objects (D…

2024 Astronomy and Astrophysics
eHST 2
Optical tomography of the born-again ejecta of A 58
DOI: 10.1051/0004-6361/202348528 Bibcode: 2024A&A...684A.107M

Guerrero, M. A.; Toalá, J. A.; Santamaría, E. +2 more

In a born-again planetary nebula (PN), processed H-deficient material has been injected inside the old, H-rich nebula as a result of a very late thermal pulse (VLTP) event. Long-slit spectra have been used to unveil the chemical and physical differences between these two structures, but the ejection and shaping processes still remain unclear. To p…

2024 Astronomy and Astrophysics
eHST 2
Secular stability of surface abundance structures in the rapidly rotating Ap star 56 Ari
DOI: 10.1051/0004-6361/202451052 Bibcode: 2024A&A...689A.111P

Potravnov, I.; Ryabchikova, T.; Piskunov, N.

The combination of the surface magnetic and abundance inhomogeneities in chemically peculiar Ap/Bp stars is responsible for their rotationally modulated variability. Within the framework of the fossil field hypothesis, these inhomogeneities are considered to be essentially stable over the main sequence timescale. However, a small group of Ap/Bp st…

2024 Astronomy and Astrophysics
Gaia 2
Spectral characterization of young LT dwarfs
DOI: 10.1051/0004-6361/202347327 Bibcode: 2024A&A...686A..37P

Scholz, A.; Mužić, K.; Almendros-Abad, V. +1 more

Context. JWST and next-generation facilities are expected to uncover populations of free-floating objects below the deuterium-burning limit in a number of young clusters and star-forming regions. These young planetary-mass brown dwarfs have spectral types L and T; they are shaped by molecular absorption and modified by their low gravity, which mak…

2024 Astronomy and Astrophysics
Gaia 2