Search Publications
SRG/ART-XC discovery of SRGA J204318.2+443815: Towards the complete population of faint X-ray pulsars
Yao, Y.; Kulkarni, S. R.; Bikmaev, I. F. +19 more
We report the discovery of the new long-period X-ray pulsar SRGA J204318.2+443815/SRGe J204319.0+443820 in a Be binary system. The source was found in the second all-sky survey by the Mikhail Pavlinsky ART-XC telescope on board the SRG mission. The follow-up observations with XMM-Newton, NICER, and NuSTAR allowed us to discover a strong coherent s…
Pulsating hydrogen-deficient white dwarfs and pre-white dwarfs observed with TESS. V. Discovery of two new DBV pulsators, WDJ152738.4−450207.4 and WD 1708−871, and asteroseismology of the already known DBV stars PG 1351+489, EC 20058−5234, and EC 04207−4748
Kepler, S. O.; Hermes, J. J.; Althaus, L. G. +9 more
Context. The TESS space mission has recently demonstrated its great potential to discover new pulsating white dwarf and pre-white dwarf stars, and to detect periodicities with high precision in already known white-dwarf pulsators.
Aims: We report the discovery of two new pulsating He-rich atmosphere white dwarfs (DBVs) and present a detailed …
Radial Velocity Survey for Planets around Young stars (RVSPY). Target characterisation and high-cadence survey
Trifonov, Trifon; Henning, Thomas; Reffert, Sabine +15 more
Context. The occurrence rate and period distribution of (giant) planets around young stars is still not as well constrained as for older main-sequence stars. This is mostly due to the intrinsic activity-related complications and the avoidance of young stars in many large planet search programmes. Yet, dynamical restructuring processes in planetary…
Fast time optical variability in Be/X-ray binaries. Pulsation and rotation
Reig, P.; Fabregat, J.
Context. Classical Be stars, regardless of spectral subtype, display multi-periodic light modulations in the frequency range 0.1-12 c d−1 when observed with a high cadence and a long duration. This behavior is attributed to non-radial pulsations and/or the rotation of the Be star. A similar study on the optical counterparts to Be/X-ray …
X-ray view of a merging supermassive black hole binary candidate SDSS J1430+2303: Results from the first ∼200 days of observations
Zheng, Zhen-Ya; Shu, Xinwen; Pan, Zhen +7 more
Context. Recently we discovered an unprecedented supermassive black hole binary (SMBHB) candidate in the nearby Seyfert galaxy SDSS J1430+2303, which is predicted to merge within three years. X-ray spectroscopy may bring unique kinematic evidence for the last inspiraling stage, when the binary is too close to allow each of them to hold an individu…
Sampling molecular gas in the Helix planetary nebula: Variation in HNC/HCN with UV flux
Kastner, J. H.; Alcolea, J.; Santander-García, M. +4 more
Context. Observations of molecular clouds, prestellar cores, and protoplanetary disks have established that the HNC/HCN ratio may be a potent diagnostic of molecular gas physical conditions. The processes that govern the relative abundances of these molecules nevertheless remain poorly understood.
Aims: We seek to exploit the wide range of UV…
Gaia EDR3 comparative study of protoplanetary disk fractions in young stellar clusters
Mendigutía, I.; Huélamo, N.; Solano, E. +4 more
Context. The lifetime of protoplanetary disks around young stars limits the timescale of planet formation. A disk dissipation timescale ≤10 Myr was inferred from surveys that count the relative number of stars with disks - the disk fraction - in young stellar clusters with different ages. However, most previous surveys focused on the compact regio…
Confirmation and characterisation of three giant planets detected by TESS from the FIES/NOT and Tull/McDonald spectrographs
Bieryla, Allyson; Quinn, Samuel N.; Cochran, William D. +37 more
We report the confirmation and characterisation of TOI-1820 b, TOI-2025 b, and TOI-2158 b, three Jupiter-sized planets on short-period orbits around G-type stars detected by TESS. Through our ground-based efforts using the FIES and Tull spectrographs, we have confirmed these planets and characterised their orbits, and find periods of around 4.9 d,…
AutoSourceID-Light. Fast optical source localization via U-Net and Laplacian of Gaussian
Groot, P. J.; Jóhannesson, G.; Vreeswijk, P. +9 more
Aims: With the ever-increasing survey speed of optical wide-field telescopes and the importance of discovering transients when they are still young, rapid and reliable source localization is paramount. We present AutoSourceID-Light (ASID-L), an innovative framework that uses computer vision techniques that can naturally deal with large amount…
Star-forming and gas-rich brightest cluster galaxies at z ∼ 0.4 in the Kilo-Degree Survey
Castignani, G.; Moscardini, L.; Radovich, M. +9 more
Brightest cluster galaxies (BCGs) are typically massive ellipticals at the centers of clusters. They are believed to experience strong environmental processing, and their mass assembly and star formation history are still debated. We have selected three star-forming BCGs in the equatorial field of the Kilo-Degree Survey (KiDS). They are KiDS 0920 …