Search Publications
A Very Metal-poor RR Lyrae Star with a Disk Orbit Found in the Solar Neighborhood
Kobayashi, Naoto; Maehara, Hiroyuki; Hattori, Kohei +28 more
Metal-deficient stars are important tracers for understanding the early formation of the Galaxy. Recent large-scale surveys with both photometric and spectroscopic data have reported an increasing number of metal-deficient stars whose kinematic features are consistent with those of the disk stellar populations. We report the discovery of an RR Lyr…
Probabilistic orbits and dynamical masses of emission-line binaries
Grant, David; Blundell, Katherine
The observed orbits of emission-line stars may be affected by systematics owing to their broad emission lines being formed in complex and extended environments. This is problematic when orbital parameter probability distributions are estimated assuming radial-velocity data are solely comprised of Keplerian motion plus Gaussian white noise, leading…
Existence of tidal tails for the globular cluster NGC 5824
Zhao, Gang; Zhao, Jing-Kun; Ishigaki, Miho N. +5 more
Context. Several dynamically cold streams have been associated with certain globular clusters (GCs) based on orbital energies and angular momenta. Some of these streams are surprisingly far apart from their progenitors and one such pair is Triangulum and NGC 5824. Triangulum can be considered as a piece of the leading tail of NGC 5824 since the cl…
White Dwarf Photospheric Abundances in Cataclysmic Variables-II. White Dwarfs with and without a Mask
Sion, Edward M.; Godon, Patrick
Taking advantage of the now-available Gaia EDR3 parallaxes, we carry out an archival Hubble Space Telescope (HST) far-ultraviolet spectroscopic analysis of 10 cataclysmic variable systems, including five carefully selected eclipsing systems. We obtain accurate white dwarf (WD) masses and temperatures, in excellent agreement with the masses for fou…
Tracing a decade of activity towards a yellow hypergiant. The spectral and spatial morphology of IRC+10420 at au scales
de Wit, W. -J.; Black, J. H.; Mérand, A. +3 more
The fate of a massive star during the latest stages of its evolution is highly dependent on its mass-loss history and geometry, with the yellow hypergiants (YHGs) being key objects. We present near-IR interferometric observations of the famous YHG IRC+10420 and blue spectra taken between 1994 and 2019. Our 2.2-µm GRAVITY/VLTI observations at…
The probabilistic random forest applied to the QUBRICS survey: improving the selection of high-redshift quasars with synthetic data
Grazian, Andrea; Murphy, Michael T.; Boutsia, Konstantina +10 more
Several recent works have focused on the search for bright, high-z quasars (QSOs) in the South. Among them, the QUasars as BRIght beacons for Cosmology in the Southern hemisphere (QUBRICS) survey has now delivered hundreds of new spectroscopically confirmed QSOs selected by means of machine learning algorithms. Building upon the results obtained b…
The uncertain interstellar medium of high-redshift quiescent galaxies: Impact of methodology
Daddi, E.; Gobat, R.; Caminha, G. B. +3 more
How much gas and dust is contained in high-redshift quiescent galaxies (QGs) is currently an open question with relatively few and contradictory answers, as well as important implications for our understanding of the nature of star formation quenching processes at cosmic noon. Here we revisit far-infrared (FIR) observations of the REQUIEM-ALMA sam…
USNO Bright Star Catalog, Version 1
Harris, Hugh C.; Munn, Jeffrey A.; Subasavage, John P. +3 more
The USNO Bright Star Catalog (UBSC) is a new astrometric catalog of the 1423 brightest stars covering the entire sky, which is published online. It is nearly complete to V = 3 mag except for three stellar systems. A combined astrometric solution of the Hipparcos Intermediate Astrometry Data and two dedicated ground-based campaigns in 2013-2020 is …
Homologous Compact Major Blowout-eruption Solar Flares and their Production of Broad CMEs
Joshi, Bhuwan; Moore, Ronald L.; Sterling, Alphonse C. +2 more
We analyze the formation mechanism of three homologous broad coronal mass ejections (CMEs) resulting from a series of solar blowout-eruption flares with successively increasing intensities (M2.0, M2.6, and X1.0). The flares originated from NOAA Active Region 12017 during 2014 March 28-29 within an interval of ≈24 hr. Coronal magnetic field modelin…
Helium-like X-ray line complexes show that the hottest plasma on the O supergiant ζ Puppis is in its wind
Leutenegger, Maurice A.; Cohen, David H.; Gagné, Marc +3 more
We present an analysis of Chandra grating spectra of key helium-like line complexes to put constraints on the location with respect to the photosphere of the hottest (T ≳ 6 × 106 K) plasma in the wind of the O supergiant ζ Pup and to explore changes in the 18 yr between two sets of observations of this star. We fit two models - one empi…