Search Publications
Large-scale expansion of OB stars in Cygnus
Quintana, Alexis L.; Wright, Nicholas J.
The proper motions (PMs) of OB stars in Cygnus have recently been found to exhibit two large-scale kinematic patterns suggestive of expansion. We perform a 3D traceback on these OB stars, the newly identified OB associations and related open clusters in the region. We find that there are two groups of stars, associations and clusters and that they…
Large-amplitude periodic outbursts and long-period variables in the VVV VIRAC2-β data base
Minniti, D.; Bayo, A.; Catelan, M. +13 more
The VISTA Variables in the Via Lactea (VVV) survey obtained near-infrared photometry towards the Galactic bulge and the southern disc plane for a decade (2010-2019). We designed a modified Lomb-Scargle method to search for large-amplitude ($\Delta K_{s, 2-98{{\ \rm per\ cent}}}$ > 1.5 mag) mid to long-term periodic variables (P> 10 d) in the…
The Quasar Feedback Survey: revealing the interplay of jets, winds, and emission-line gas in type 2 quasars with radio polarization
Mainieri, V.; Harrison, C. M.; Jarvis, M. E. +4 more
We present results from a combined radio polarization and emission-line study of five type 2 quasars at z < 0.2 with the Karl G. Jansky Very Large Array (VLA) B-array at 5 GHz and Hubble Space Telescope (HST) [O III] observations. These five sources are known to exhibit close association between radio structures and ionized gas morphology and k…
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…