Related papers: Science with an ngVLA: Evolved Stars
The last findings on stellar and substellar objects in modified gravity are presented, allowing a reader to quickly jump into this topic. Early stellar evolution of low-mass stars, cooling models of brown dwarfs and giant gaseous exoplanets…
We study the asymptotic giant branch (AGB) evolution of stars with masses between $1~M_{\odot} - 8.5~M_{\odot}$. We focus on stars with a solar chemical composition, which allows us to interpret evolved stars in the Galaxy. We present a…
The Asymptotic Giant Branch (AGB) is the terminal phase of red giant evolution with timescales of millions of years and a total mass lost from the star that is a significant fraction of the initial mass. Investigation of one of these stars,…
The formation and evolution of disks early in the protostellar phase is an area of study in which the ngVLA is poised to make significant breakthroughs. The high-sensitivity and resolution at wavelengths of 3~mm and longer will enable…
Continuum observations of molecular clouds have revealed a surprising amount of substructure in the form of filaments of a few pc length and cores of ~0.1 pc diameter. Understanding the evolution of these substructures towards star…
Galactic winds are ubiquitously observed in galaxies both locally and in the high-redshift Universe. While these winds span many orders of magnitude in both temperature and density, observations of nearby galaxies show that the cold…
About ten percent of Sun-like ($1$-$2 M_\odot$) stars will engulf a $1$-$10 M_{\rm J}$ planet as they expand during the red giant branch (RGB) or asymptotic giant branch (AGB) phase of their evolution. Once engulfed, these planets…
We have conducted a near-infrared monitoring campaign at the UK InfraRed Telescope, of the Local Group spiral galaxy M33. The main aim was to identify stars in the very final stage of their evolution, and for which the luminosity is more…
We review the observed properties of extremely hot hydrogen-deficient post-AGB stars of spectral type [WC] and PG1159. Their H-deficiency is probably caused by a (very) late helium-shell flash or a AGB final thermal pulse, laying bare…
We show that the inclusion of axion emission during stellar evolution introduces important changes into the evolutionary behaviour of AGB stars. The mass of the resulting C/O white dwarf is much lower than the equivalent obtained from…
The science case and associated science requirements for a next-generation Very Large Array (ngVLA) are described, highlighting the five key science goals developed out of a community-driven vision of the highest scientific priorities in…
The determinations of element abundances in red-giant stars and in particular in AGB stars are reviewed and the resulting abundances are compared with those obtained for planetary nebulae in the Galaxy and in nearby galaxies. The problems,…
We present models of the extragalactic background light (EBL) based on several scenarios of galaxy formation and evolution. We have treated galaxy formation with the Press-Schecter approximation for both cold dark matter (CDM) and cold+hot…
A revival over the past two decades in planetary nebula (PN) morphological studies springs from a combination of factors, including the advent of wide-area, high dynamic range detectors; the growing archives of high resolution images from…
My presentation was an overview of what we know about the Local Group of galaxies, primarily from optical imaging and spectroscopy. AGB stars are on the whole a very sparse and unrepresentative stellar population in most Local Group…
In this paper we study the evolution of 7Li in the Galaxy considering the contributions of various stellar sources: type II supernovae, novae, red giant stars, and asymptotic giant branch (AGB) stars. We present new results for the…
The discovery of the M-sigma relation, the local galaxy bimodality, and the link between black-hole and host-galaxy properties, have raised the question whether AGN play a role in galaxy evolution. Several theoretical models implement AGN…
We examine the envelope properties of asymptotic giant branch (AGB) stars as they evolve on the upper AGB and during the early post-AGB phase. Due to the high mass loss rate, the envelope mass decreases by more than an order of magnitude.…
AGB variables, particularly the large amplitude Mira type, are a vital step on the distance scale ladder. They will prove particularly important in the era of space telescopes and extremely large ground-based telescopes with adaptive…
Late asymptotic giant branch (AGB) and early post-AGB stars which are progenitors of planetary nebulae lose mass at extremely high rate, in what is termed a superwind. We show that the existence of this superwind during the post-AGB phase…