Search Publications
ASAS J071404+7004.3 - a close, bright nova-like cataclysmic variable with gusty winds
Knigge, C.; Gänsicke, B. T.; Marsh, T. R. +11 more
Despite being bright (V ≃ 11.8) and nearby (d = 212 pc) ASAS J071404+7004.3 has only recently been identified as a nova-like cataclysmic variable. We present time-resolved optical spectroscopy obtained at the Isaac Newton and the Hiltner and McGraw-Hill Telescopes, together with Swift X-ray and ultraviolet observations. We combined these with TESS…
REXCOR: a model of the X-ray spectrum of active galactic nuclei that combines ionized reflection and a warm corona
Bianchi, S.; Petrucci, P. -O.; Matt, G. +6 more
The X-ray spectra of active galactic nuclei (AGNs) often exhibit an excess of emission above the primary power law at energies ≲2 keV. Two models for the origin of this 'soft excess' are ionized relativistic reflection from the inner accretion disc and Comptonization of thermal emission in a warm corona. Here, we introduce REXCOR, a new AGN X-ray …
A gap in the double white dwarf separation distribution caused by the common-envelope evolution: astrometric evidence from Gaia
Toonen, Silvia; Belokurov, Vasily; Korol, Valeriya
The trajectory of the center of light of an unresolved binary is different from that of its center of mass. Binary-induced stellar centroid wobbling can therefore be detected as an excess in the goodness-of-fit of the single-star astrometric model. We use reduced χ2 of the astrometric fit in the Gaia Early Data Release 3 to detect the l…
The average dust attenuation curve at z 1.3 based on HST grism surveys
Malkan, M. A.; Calzetti, D.; Scarlata, C. +12 more
We present the first characterization of the average dust attenuation curve at z ~ 1.3 by combining rest-frame ultraviolet through near-IR photometry with Balmer decrement (H α/H β) constraints for ~900 galaxies with 8 ≲ log (M⋆/M⊙) < 10.2 at 0.75 < z < 1.5 in the HST WFC3 IR Spectroscopic Parallel and 3D-HST grism s…
A new emulated Monte Carlo radiative transfer disc-wind model: X-Ray Accretion Disc-wind Emulator - XRADE
Brusa, M.; Dadina, M.; Reeves, J. N. +14 more
We present a new X-Ray Accretion Disc-wind Emulator (XRADE) based on the 2.5D Monte Carlo radiative transfer code that provides a physically motivated, self-consistent treatment of both absorption and emission from a disc wind by computing the local ionization state and velocity field within the flow. XRADE is then implemented through a process th…
Photometric characterization and trajectory accuracy of Starlink satellites: implications for ground-based astronomical surveys
Battle, Adam; Campbell, Tanner; Reddy, Vishnu +2 more
Starlink is a low-Earth orbit (LEO) satellite constellation operated by Space Exploration Technologies Corp. (SpaceX) which aims to provide global satellite internet access. Thus far, most photometric observations of Starlink satellites have primarily been from citizen scientists' visual observations without using quantitative detectors. This pape…
Discovery and analysis of three magnetic hot subdwarf stars: evidence for merger-induced magnetic fields
Geier, S.; Heber, U.; Pelisoli, Ingrid +6 more
Magnetic fields can play an important role in stellar evolution. Among white dwarfs, the most common stellar remnant, the fraction of magnetic systems is more than 20 per cent. The origin of magnetic fields in white dwarfs, which show strengths ranging from 40 kG to hundreds of MG, is still a topic of debate. In contrast, only one magnetic hot sub…
The Nearby Evolved Stars Survey II: Constructing a volume-limited sample and first results from the James Clerk Maxwell Telescope
Kim, J.; Menten, K. M.; Marshall, J. P. +89 more
The Nearby Evolved Stars Survey (NESS) is a volume-complete sample of ~850 Galactic evolved stars within 3 kpc at (sub-)mm wavelengths, observed in the CO J = (2-1) and (3-2) rotational lines, and the sub-mm continuum, using the James Clark Maxwell Telescope and Atacama Pathfinder Experiment. NESS consists of five tiers, based on distances and dus…
Computing optical meteor flux using global meteor network data
Vida, Denis; Brown, Peter G.; Campbell-Brown, Margaret +3 more
Meteor showers and their outbursts are the dominant source of meteoroid impact risk to spacecraft on short time-scales. Meteor shower prediction models depend on historical observations to produce accurate forecasts. However, the current lack of quality and persistent world-wide monitoring at optical meteoroid sizes has left some recent major outb…
Where are the magnetar binary companions? Candidates from a comparison with binary population synthesis predictions
Lyman, J. D.; Kouveliotou, C.; Fruchter, A. S. +7 more
It is well established that magnetars are neutron stars with extreme magnetic fields and young ages, but the evolutionary pathways to their creation are still uncertain. Since most massive stars are in binaries, if magnetars are a frequent result of core-collapse supernovae, some fractions are expected to have a bound companion at the time of obse…