Search Publications
Photometric determination of the mass accretion rates of pre-main-sequence stars. VIII. Recent star formation in NGC 299
De Marchi, G.; Vlasblom, M.
We studied the properties of the young stellar populations in the NGC 299 cluster in the Small Magellanic Cloud using observations obtained with the Hubble Space Telescope in the V, I, and Hα bands. We identified 250 stars with Hα excess exceeding 5σ and an equivalent width of the Hα emission line of at least 20 Å, which indicates that these stars…
Spectropolarimetry and spectral decomposition of high-accreting narrow-line Seyfert 1 galaxies
Czerny, Bożena; Martínez-Aldama, Mary Loli; Panda, Swayamtrupta +7 more
Context. Narrow-line Seyfert 1 (NLSy1) galaxies have been shown to have high Eddington ratios and relatively small black hole mass. The measurement of these black hole masses is based on the virial relation that is dependent on the distribution of the line-emitting gas and the viewing angle to the source. Spectropolarimetry enables us to probe the…
The ESO UVES/FEROS Large Programs of TESS OB pulsators. I. Global stellar parameters from high-resolution spectroscopy
Sana, Hugues; Bowman, Dominic M.; Aerts, Conny +7 more
Context. Modern stellar structure and evolution theory suffers from a lack of observational calibration for the interior physics of intermediate- and high-mass stars. This leads to discrepancies between theoretical predictions and observed phenomena that are mostly related to angular momentum and element transport. Analyses of large samples of mas…
Degree of stochastic asymmetry in the tidal tails of star clusters
Prusti, T.; Beccari, G.; Boffin, H. M. J. +4 more
Context. Tidal tails of star clusters are commonly understood to be populated symmetrically. Recently, the analysis of Gaia data revealed large asymmetries between the leading and trailing tidal tail arms of the four open star clusters Hyades, Praesepe, Coma Berenices, and NGC 752.
Aims: As the evaporation of stars from star clusters into the…
Chasing ICM cooling and AGN feedback from the macro to the meso scales in the galaxy cluster ZwCl 235
Gitti, M.; Brighenti, F.; Ubertosi, F.
Aims: We aim to investigate the interplay between the intracluster medium (ICM) and the active galactic nucleus (AGN) in ZwCl 235, a galaxy cluster with high X-ray flux, an extended central radio galaxy, and evidence of multiphase gas at its center.
Methods: Using archival data from the Chandra telescope, the Very Large Array Sky Survey …
Dynamical detection of a companion driving a spiral arm in a protoplanetary disk
Dong, Ruobing; Ren, Bin B.; Wagner, Kevin +6 more
Radio and near-infrared observations have observed dozens of protoplanetary disks that host spiral arm features. Numerical simulations have shown that companions may excite spiral density waves in protoplanetary disks via companion-disk interaction. However, the lack of direct observational evidence for spiral-driving companions poses challenges t…
Photometric determination of the mass accretion rates of pre-main-sequence stars. VII. The low-density cluster NGC 376 in the Small Magellanic Cloud
Panagia, Nino; De Marchi, Guido; Tsilia, Styliani
Aims: We study the properties of low-mass stars recently formed in the field of the NGC 376 cluster in the Small Magellanic Cloud (SMC).
Methods: Using photometric observations acquired with the Hubble Space Telescope (HST) in the V, I, and Hα bands, we identify 244 candidate pre-main-sequence (PMS) stars showing Hα excess emission at th…
J-NEP: 60-band photometry and photometric redshifts for the James Webb Space Telescope North Ecliptic Pole Time-Domain Field
Hernández-Monteagudo, C.; Hernán-Caballero, A.; Mendes de Oliveira, C. +28 more
The Javalambre-Physics of the Accelerating Universe Astrophysical Survey (J-PAS) will observe approximately one-third of the northern sky with a set of 56 narrow-band filters using the dedicated 2.55 m Javalambre Survey Telescope (JST) at the Javalambre Astrophysical Observatory. Prior to the installation of the main camera, in order to demonstrat…
Initiation mechanism of the first on-disk X-class flare of solar cycle 25
Feng, Xueshang; Duan, Aiying; Jiang, Chaowei +1 more
In this paper we study the initiation mechanism of the first on-disk X-class eruptive flare in solar cycle 25. Coronal magnetic field reconstructions reveal a magnetic flux rope (MFR) whose configuration is highly consistent with a filament existing for a long period before the flare; the eruption of the whole filament indicates that the MFR erupt…
Imaging of exocomets with infrared interferometry
Janson, Markus; Rebollido, Isabel; Brandeker, Alexis +6 more
Active comets have been detected in several exoplanetary systems, although so far only indirectly, when the dust or gas in the extended coma has transited in front of the stellar disk. The large optical surface and relatively high temperature of an active cometary coma also makes it suitable to study with direct imaging, but the angular separation…