Search Publications
A Possible 250 s X-Ray Quasi-periodicity in the Fast Blue Optical Transient AT2018cow
Tao, Lian; Zhang, Liang; Shu, Xinwen +11 more
The fast blue optical transients (FBOTs) are a new population of extragalactic transients of unclear physical origin. A variety of mechanisms has been proposed including failed supernova explosion, shock interaction with a dense medium, young magnetar, accretion onto a compact object and stellar tidal disruption event, but none is conclusive. Here…
A First Look into the Nature of JWST/MIRI 7.7 µm Sources from SMACS 0723
Rinaldi, Pierluigi; Caputi, Karina I.; Iani, Edoardo +1 more
Until now, our knowledge of the extragalactic universe at mid-infrared (mid-IR) wavelengths (>5 µm) was limited to rare active galactic nuclei and the brightest normal galaxies up to z ~ 3. The advent of JWST with its Mid-Infrared Instrument (MIRI) will revolutionize the ability of the mid-IR regime as a key wavelength domain to probe the…
Distance and age of the massive stellar cluster Westerlund 1. I. Parallax method using Gaia-EDR3
Damineli, Augusto; Navarete, Felipe; Almeida, Leonardo A. +2 more
Westerlund 1 (Wd 1) is one of the most massive young star clusters in the Milky Way. Although relevant for star formation and evolution, its fundamental parameters are not yet very well constrained. We aim to derive an accurate distance and provide constraints on the cluster age. We used the photometric and astrometric information available in the…
HST/WFC3 Complete Phase-resolved Spectroscopy of White-dwarf-brown-dwarf Binaries WD 0137 and EPIC 2122
Mayorga, L. C.; Lothringer, Joshua D.; Apai, Dániel +7 more
Brown dwarfs in close-in orbits around white dwarfs offer an excellent opportunity to investigate properties of fast-rotating, tidally locked, and highly irradiated atmospheres. We present Hubble Space Telescope Wide Field Camera 3 G141 phase-resolved observations of two brown-dwarf-white-dwarf binaries: WD 0137-349 and EPIC 212235321. Their 1.1-1…
Microlensing Events in the Galactic Plane Using the Zwicky Transient Facility
Duev, Dmitry A.; Riddle, Reed; Mróz, Przemek +10 more
Microlensing is a powerful technique to study the Galactic population of "dark" objects such as exoplanets both bound and unbound, brown dwarfs, low-luminosity stars, old white dwarfs, and neutron stars, and it is almost the only way to study isolated stellar-mass black holes. The majority of previous efforts to search for gravitational microlensi…
The OmegaWhite survey for short-period variable stars - VII. High amplitude short-period blue variables
Ramsay, Gavin; Buckley, David A. H.; Kupfer, Thomas +11 more
Blue Large-Amplitude Pulsators (BLAPs) are a relatively new class of blue variable stars showing periodic variations in their light curves with periods shorter than a few tens of minutes and amplitudes of more than 10 per cent. We report nine blue variable stars identified in the OmegaWhite survey conducted using ESO's VST, which shows a periodic …
The tidal evolution of the Fornax dwarf spheroidal and its globular clusters
Fattahi, Azadeh; Navarro, Julio F.; Errani, Raphaël +2 more
The dark matter content of the Fornax dwarf spheroidal galaxy inferred from its kinematics is substantially lower than expected from LCDM cosmological simulations. We use N-body simulations to examine whether this may be the result of Galactic tides. We find that, despite improved proper motions from the Gaia mission, the pericentric distance of F…
eROSITA calibration and performance verification phase: High-mass X-ray binaries in the Magellanic Clouds
Haberl, F.; Udalski, A.; Freyberg, M. J. +8 more
Context. During its performance verification phase, the soft X-ray instrument eROSITA on board the Spektrum-Roentgen-Gamma (SRG) spacecraft observed large regions in the Magellanic Clouds in which almost 40 known high-mass X-ray binaries (HMXBs, including candidates) are located.
Aims: We looked for new HMXBs in the eROSITA data, searched for…
The origin of early-type runaway stars from open clusters
Heber, U.; Irrgang, A.; Bhat, A.
Runaway stars are ejected from their place of birth in the Galactic disk, with some young B-type runaways found several tens of kiloparsecs from the plane traveling at speeds beyond the escape velocity, which calls for violent ejection processes. Young open clusters are a likely place of origin, and ejection may be either through N-body interactio…
A Temperature Trend for Clouds and Hazes in Exoplanet Atmospheres
Swain, Mark R.; Estrela, Raissa; Roudier, Gael M.
The transmission spectra of exoplanet atmospheres observed with the Hubble Space Telescope (HST) in the near-infrared range (1.1-1.65 µm) frequently show evidence for some combination of clouds and hazes. Identification of systematic trends in exoplanet clouds and hazes is potentially important for understanding atmospheric composition and t…