Search Publications
A detailed non-LTE analysis of LB-1: Revised parameters and surface abundances
Allende Prieto, C.; Smartt, S. J.; Dufton, P. L. +8 more
Context. It has recently been proposed that LB-1 is a binary system at 4 kpc consisting of a B-type star of 8 M⊙ and a massive stellar black hole (BH) of 70 M⊙. This finding challenges our current theories of massive star evolution and formation of BHs at solar metallicity.
Aims: Our objective is to derive the effective …
Observations of the 2019 April 4 Solar Energetic Particle Event at the Parker Solar Probe
Krimigis, S. M.; Mitchell, D. G.; McComas, D. J. +33 more
A solar energetic particle event was detected by the Integrated Science Investigation of the Sun (IS⊙IS) instrument suite on Parker Solar Probe (PSP) on 2019 April 4 when the spacecraft was inside of 0.17 au and less than 1 day before its second perihelion, providing an opportunity to study solar particle acceleration and transport unprecedentedly…
Recipes for bolometric corrections and Gaia luminosities of B-type stars: application to an asteroseismic sample
Aerts, Conny; Escorza, Ana; Pedersen, May G. +1 more
We provide three statistical model prescriptions for the bolometric corrections appropriate for B-type stars as a function of (I) Teff, (II) Teff and log g, and (III)Teff, log g and [M/H]. These statistical models have been calculated for 27 different filters, including those of the Gaia space mission, and were der…
From Nuclear to Circumgalactic: Zooming in on AGN-driven Outflows at z ∼ 2.2 with SINFONI
Lutz, D.; Wuyts, S.; Förster Schreiber, N. M. +16 more
We use deep adaptive optics assisted integral field spectroscopy from SINFONI on the VLT to study the spatially resolved properties of ionized gas outflows driven by active galactic nuclei (AGNs) in three galaxies at z ∼ 2.2—K20-ID5, COS4-11337, and J0901 + 1814. These systems probe AGN feedback from nuclear to circumgalactic scales and provide un…
Classifying Single Stars and Spectroscopic Binaries Using Optical Stellar Templates
Roulston, Benjamin R.; Green, Paul J.; Kesseli, Aurora Y.
Stellar spectral classification is a fundamental tool of modern astronomy, providing insight into physical characteristics such as effective temperature, surface gravity, and metallicity. Accurate and fast spectral typing is an integral need for large all-sky spectroscopic surveys like the Sloan Digital Sky Survey (SDSS) and the Large Sky Area Mul…
Evolved massive stars at low metallicity. II. Red supergiant stars in the Small Magellanic Cloud
Yang, Ming; Bonanos, Alceste Z.; Jiang, Bi-Wei +9 more
We present the most comprehensive red supergiant (RSG) sample for the Small Magellanic Cloud (SMC) to date, including 1239 RSG candidates. The initial sample was derived based on a source catalog for the SMC with conservative ranking. Additional spectroscopic RSGs were retrieved from the literature, and RSG candidates were selected based on the in…
The SUrvey for Pulsars and Extragalactic Radio Bursts - IV. Discovery and polarimetry of a 12.1-s radio pulsar
Ray, P. S.; Kramer, M.; Johnston, S. +19 more
We report the discovery of PSR J2251-3711, a radio pulsar with a spin period of 12.1 s, the second longest currently known. Its timing parameters imply a characteristic age of 15 Myr, a surface magnetic field of 1.3 × 1013 G, and a spin-down luminosity of 2.9 × 1029 erg s-1. Its dispersion measure of 12.12(1) pc cm…
Global helium abundance measurements in the solar corona
Telloni, Daniele; Antonucci, Ester; Fineschi, Silvano +24 more
Solar abundances have been historically assumed to be representative of cosmic abundances. However, our knowledge of the solar abundance of helium, the second most abundant element, relies mainly on models1 and indirect measurements through helioseismic observations2, because actual measurements of helium in the solar atmosph…
Core-collapse supernovae in binaries as the origin of galactic hyper-runaway stars
Rossi, E. M.; Renzo, M.; Evans, F. A.
Several stars detected moving at velocities near to or exceeding the Galactic escape speed likely originated in the Milky Way disc. We quantitatively explore the 'binary supernova scenario' hypothesis, wherein these 'hyper-runaway' stars are ejected at large peculiar velocities when their close, massive binary companions undergo a core-collapse su…
MKT J170456.2-482100: the first transient discovered by MeerKAT
Heywood, I.; Wijers, R. A. M. J.; Woudt, P. A. +19 more
We report the discovery of the first transient with MeerKAT, MKT J170456.2-482100, discovered in ThunderKAT images of the low-mass X-ray binary GX339-4. MKT J170456.2-482100 is variable in the radio, reaching a maximum flux density of 0.71± 0.11 mJy on 2019 October 12, and is undetected in 15 out of 48 ThunderKAT epochs. MKT J170456.2-482100 is co…