Search Publications
Supercritical colliding wind binaries
Romero, Gustavo E.; Abaroa, Leandro; Sotomayor, Pablo
Context. Particle-accelerating colliding-wind binaries (PACWBs) are systems that are formed by two massive and hot stars and produce nonthermal radiation. The key elements of these systems are fast winds and the shocks that they create when they collide. Binaries with nonaccreting young pulsars have also been detected as nonthermal emitters, again…
NGC 2992: Interplay between the multiphase disc, wind, and radio bubbles
Fiore, F.; Massardi, M.; Lapi, A. +13 more
We present an analysis of the gas kinematics in NGC 2992 based on VLT/MUSE, ALMA, and VLA data. Our aim is to characterise the disc, the wind, and their interplay in the cold molecular and warm ionised phases. NGC 2992 is a changing-look Seyfert known to host both a nuclear ultrafast outflow (UFO), and an AGN-driven kiloparsec-scale ionised wind. …
Constraints on the Galactic centre environment from Gaia hypervelocity stars III: insights on a possible companion to Sgr A*
Rossi, E. M.; Castro-Ginard, A.; Marchetti, T. +4 more
We consider a scenario in which Sgr A* is in a massive black hole binary (MBHB) with an as-of-yet undetected supermassive or intermediate-mass black hole companion. Dynamical encounters between this MBHB and single stars in its immediate vicinity would eject hypervelocity stars (HVSs) with velocities beyond the Galactic escape velocity of the Gala…
Near to Mid-infrared Spectroscopy of (65803) Didymos as Observed by JWST: Characterization Observations Supporting the Double Asteroid Redirection Test
de León, Julia; Lucchetti, Alice; Pajola, Maurizio +17 more
The Didymos binary asteroid was the target of the Double Asteroid Redirection Test (DART) mission, which intentionally impacted Dimorphos, the smaller member of the binary system. We used the Near-Infrared Spectrograph and Mid-Infrared Instrument instruments on JWST to measure the 0.6-5 and 5-20 µm spectra of Didymos approximately two months…
Nearby galaxies in the LOFAR Two-metre Sky Survey. II. The magnetic field-gas relation
Beck, R.; Drabent, A.; Brüggen, M. +8 more
Context. Magnetic fields, which regulate stellar feedback and star formation in galaxies, are key to understanding galaxy evolution.
Aims: We probe the origin of magnetic fields in late-type galaxies, measuring magnetic field strengths and exploring whether magnetic fields are only passive constituents of the interstellar medium or whether, b…
Source counts at 7.7-21 µm in CEERS field with JWST
Kilerci, Ece; Hashimoto, Tetsuya; Goto, Tomotsugu +8 more
Source counts - the number density of sources as a function of flux density - represent one of the fundamental metrics in observational cosmology due to their straightforward and simple nature. It is an important tool that provides information on galaxy formation and evolution. Source counting is a direct measurement. Compared to advanced analyses…
Barium stars as tracers of s-process nucleosynthesis in AGB stars. II. Using machine learning techniques on 169 stars
Pereira, C. B.; Cseh, B.; Drake, N. A. +7 more
Context. Barium (Ba) stars are characterised by an abundance of heavy elements made by the slow neutron capture process (s-process). This peculiar observed signature is due to the mass transfer from a stellar companion, bound in a binary stellar system, to the Ba star observed today. The signature is created when the stellar companion is an asympt…
WD J004917.14-252556.81: the most massive pulsating white dwarf
Córsico, Alejandro H.; Althaus, Leandro G.; Kilic, Mukremin +3 more
We present Apache Point Observatory (APO) and Gemini time-series photometry of WD J004917.14-252556.81, an ultramassive DA white dwarf with $T_{\rm eff} = 13\, 020$ K and log g = 9.34. We detect variability at two significant frequencies, making J0049-2525 the most massive pulsating white dwarf currently known with M⋆ = 1.31 M⊙
The stellar population responsible for a kiloparsec-size superbubble seen in the JWST 'phantom' images of NGC 628
Luna, A.; Gómez-González, V. M. A.; Mayya, Y. D. +11 more
We here study the multiband properties of a kiloparsec-size superbubble in the late-type spiral galaxy NGC 628. The superbubble is the largest of many holes seen in the early release images using James Webb Space Telescope (JWST)/MIRI filters that trace the polycyclic aromatic hydrocarbon (PAH) emissions. The superbubble is located in the interarm…
An Investigation of Open Clusters Berkeley 68 and Stock 20 Using CCD UBV and Gaia DR3 Data
Yontan, Talar
We performed detailed photometric and astrometric analyses of the open star clusters Berkeley 68 and Stock 20. This was based on ground-based CCD UBV photometric data complemented by space-based Gaia Data Release 3 (DR3) photometry and astrometry. A total of 198 and 51 stars were identified as likely cluster members for Berkeley 68 and Stock 20, r…