Search Publications
Systematic broad-band X-ray study of super-Eddington accretion on to supermassive black holes - I. X-ray continuum
Ho, Luis C.; Ricci, Claudio; Tombesi, Francesco +6 more
We present the first systematic broad-band X-ray study of super-Eddington accretion onto supermassive black holes with simultaneous NuSTAR and XMM-Newton or Swift/XRT observations of a sample of eight super-Eddington accreting Active Galactic Nuclei (AGNs) with Eddington ratio 1 < λ Edd < 426. We find that the super-Eddington accr…
A study of nine compact triply eclipsing triples
Mitnyan, T.; Pál, A.; Vanderburg, A. +22 more
In this work, we report the independent discovery and analysis of nine new compact triply eclipsing triple star systems found with the Transiting Exoplanet Survey Satellite (TESS) mission: TICs 47151245, 81525800, 99013269, 229785001, 276162169, 280883908, 294803663, 332521671, and 356324779. Each of these nine systems exhibits distinct third-body…
DAHe white dwarfs from the DESI Survey
Brooks, D.; Honscheid, K.; Miquel, R. +16 more
A new class of white dwarfs, dubbed DAHe, that present Zeeman-split Balmer lines in emission has recently emerged. However, the physical origin of these emission lines remains unclear. We present here a sample of 21 newly identified DAHe systems and determine magnetic field strengths and (for a subset) periods that span the ranges of ≃6.5-147 MG a…
The Unified Cluster Catalogue: towards a comprehensive and homogeneous data base of stellar clusters
Perren, Gabriel I.; Pera, María S.; Navone, Hugo D. +1 more
We introduce the Unified Cluster Catalogue, the largest catalogue of stellar clusters currently listing nearly 14 000 objects. In this initial release, it exclusively contains Milky Way open clusters, with plans to include other objects in future updates. Each cluster is processed using a novel probability membership algorithm, which incorporates …
Two decades of optical timing of the shortest-period binary star system HM Cancri
Dhillon, V. S.; Hollands, Mark; Parsons, Steven G. +15 more
The shortest-period binary star system known to date, RX J0806.3+1527 (HM Cancri), has now been observed in the optical for more than two decades. Although it is thought to be a double degenerate binary undergoing mass transfer, an early surprise was that its orbital frequency, f0, is currently increasing as the result of gravitational …
Benchmarking MESA isochrones against the Hyades single star sequence
Brandner, Wolfgang; Calissendorff, Per; Kopytova, Taisiya
Based on GAIA Early Data Release 3 (EDR3), we revisit and update our sample of bonafide single stars in the Hyades open cluster. The small observational uncertainties in parallax and photometry of EDR3 result in a tightly defined stellar sequence, which is ideal for the testing and calibration of theoretical stellar evolutionary tracks and isochro…
The ALMA REBELS Survey: discovery of a massive, highly star-forming, and morphologically complex ULIRG at z = 7.31
Inami, H.; Bowler, R. A. A.; Rybak, M. +27 more
We present Atacama Large Millimeter/Submillimeter Array (ALMA) [C II] and ~158 $\rm \mu m$ continuum observations of REBELS-25, a massive, morphologically complex ultra-luminous infrared galaxy (ULIRG; LIR = $1.5^{+0.8}_{-0.5} \times 10^{12}$ L⊙) at z = 7.31, spectroscopically confirmed by the Reionization Era Bright Emission…
Estimating reddening of the continuum and broad-line region of active galactic nuclei: the mean reddening of NGC 5548 and the size of the accretion disc
Gaskell, C. Martin; Anderson, Frances C.; Birmingham, Sufia Á. +1 more
We use seven different methods to estimate broad-line and continuum reddenings of NGC 5548. We investigate two possible reddening curves considered for active galactic nuclei (AGNs): the mean AGN reddening curve of Gaskell & Benker (2007) which is relatively flat in the ultraviolet, and a curve that rises strongly into the ultraviolet like a S…
Analytic model for off-axis GRB afterglow images - geometry measurement and implications for measuring H0
Nakar, Ehud; Govreen-Segal, Taya
We present an analytic model for measuring the jet core angle (θc) and viewing angle (θobs) of off-axis gamma-ray bursts independently of the jet angular structure outside of the core. We model the images of off-axis jets, and using this model, we show that θobs and θc can be measured using any two of th…
Characterizing three-dimensional magnetic field, turbulence, and self-gravity in the star-forming region L1688
Lazarian, A.; Hu, Yue
Interaction of three-dimensional magnetic fields, turbulence, and self-gravity in the molecular cloud is crucial in understanding star formation but has not been addressed so far. In this work, we target the low-mass star-forming region L1688 and use the spectral emissions of 12CO, 13CO, C18O, and H I, as well as p…