Search Publications
The ionised and molecular mass of post-common-envelope planetary nebulae. The missing mass problem
Alcolea, J.; Santander-García, M.; Bujarrabal, V. +2 more
Context. Most planetary nebulae (PNe) show beautiful, axisymmetric morphologies despite their progenitor stars being essentially spherical. Close binarity is widely invoked to help eject an axisymmetric nebula, after a brief phase of engulfment of the secondary within the envelope of the asymptotic giant branch (AGB) star, known as the common enve…
Thermal emission from bow shocks. II. 3D magnetohydrodynamic models of ζ Ophiuchi
Kavanagh, Patrick; Green, Samuel; Mackey, Jonathan +3 more
The nearby, massive, runaway star ζ Ophiuchi has a large bow shock detected in optical and infrared light and, uniquely among runaway O stars, diffuse X-ray emission detected from the shocked stellar wind. Here we make the first detailed computational investigation of the bow shock of ζ Ophiuchi, to test whether a simple model of the bow shock can…
Non-local thermodynamic equilibrium spectral analysis of five hot, hydrogen-deficient pre-white dwarfs
Raddi, Roberto; Munari, Ulisse; Werner, Klaus +3 more
Hot, compact, hydrogen-deficient pre-white dwarfs (pre-WDs) with effective temperatures of Teff > 70 000 K and a surface gravity of 5.0 < logg < 7.0 are rather rare objects despite recent and ongoing surveys. It is believed that they are the outcome of either single star evolution (late helium-shell flash or late helium-core fl…
XMM-Newton and Swift observations of supergiant high mass X-ray binaries
Romano, P.; Ferrigno, C.; Bozzo, E.
Wind-fed supergiant X-ray binaries are precious laboratories not only to study accretion under extreme gravity and magnetic field conditions, but also to probe the still highly debated properties of massive star winds. These include clumps, originating from the inherent instability of line driven winds, and larger structures. In this paper we repo…
Ca II triplet spectroscopy of Small Magellanic Cloud red giants. VI. Analysis of chemical properties of the main body
Geisler, D.; Mauro, F.; Angelo, M. S. +5 more
Aims: In this paper we analyze the chemical evolution of the main body of the SMC, adding six additional clusters to previously published samples, based on homogeneously determined and accurate metallicities.
Methods: We derived radial velocities and Ca II Triplet (CaT) metallicity of more than 150 red giants stars in six SMC star cluste…
Properties and applications of a predicted population of runaway He-sdO/B stars ejected from single degenerate He-donor SNe
Geier, S.; Justham, S.; Neunteufel, P. +4 more
Context. Thermonuclear supernovae (SNe), a subset of which are the highly important SNe of Type Ia and Iax, are relatively poorly understood phenomena. One of the more promising scenarios leading up to the creation of a thermonuclear SN involves accretion of helium-rich material from a binary companion. Following the SN, the binary companion is th…
Quasar and galaxy classification using Gaia EDR3 and CatWise2020
Bailer-Jones, Coryn A. L.; Hughes, Arvind C. N.; Jamal, Sara
In this work, we assess the combined use of Gaia photometry and astrometry with infrared data from CatWISE in improving the identification of extragalactic sources compared to the classification obtained using Gaia data. Here we perform a comprehensive study in which we assess different input feature configurations and prior functions to identify …
The peculiar abundances of HE 1005-1439. A carbon-enhanced extremely metal-poor star contaminated with products of both s- and i-process nucleosynthesis
Goswami, Aruna; Goswami, Partha Pratim
Context. Understanding the surface chemical composition of carbon-enhanced metal-poor (CEMP) stars with enhanced abundances of heavy elements remains problematic.
Aims: One of the primary objectives is to investigate the origin of the peculiar abundance pattern observed in the carbon-enhanced extremely metal-poor object HE 1005-1439, which is…
Plausibility of ultraviolet burst generation in the low solar chromosphere
Cheng, Guanchong; Ni, Lei; Lin, Jun
Context. Ultraviolet (UV) bursts and Ellerman bombs (EBs) are small-scale magnetic reconnection events taking place in the highly stratified, low solar atmosphere. The plasma density, reconnection mechanisms, radiative cooling and transfer processes clearly differ from one layer of the atmosphere to the next. In particular, EBs are believed to for…
Are the host galaxies of long gamma-ray bursts more compact than star-forming galaxies of the field?
Le Floc'h, E.; Vergani, S. D.; Schneider, B. +2 more
Context. Long gamma-ray bursts (GRBs) offer a promising tool for tracing the cosmic history of star formation, especially at high redshift, where conventional methods are known to suffer from intrinsic biases. Previous studies of GRB host galaxies at low redshift showed that high surface density of stellar mass and high surface density of star for…