相关论文: Continuum emission around AGB stars at 1.2 mm
To measure the mass loss from dusty oxygen-rich (O-rich) evolved stars in the Large Magellanic Cloud (LMC), we have constructed a grid of models of spherically-symmetric dust shells around stars with constant mass-loss rates using 2Dust.…
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,…
We present \emph{Spitzer} IRS data on 19 asymptotic giant branch (AGB) stars in the Large Magellanic Cloud, complementing existing published data sets of carbon stars in both Magellanic Clouds and the Milky Way, to investigate the effects…
Certain types of large amplitude AGB variable are proving to be powerful distance indicators that will rival Cepheids in the JWST era of high precision infrared photometry. These are predominantly found in old populations and have low mass…
The purpose of this work is to present an extensive grid of dynamical atmosphere and wind models for M-type AGB stars, covering a wide range of relevant stellar parameters. We used the DARWIN code, which includes frequency-dependent…
In the late stage of their evolution, low- to intermediate-mass stars pass through the asymptotic giant branch (AGB) phase, characterised by strong mass loss through dust driven winds. High angular resolution observations reveal that these…
This is the first publication of the DEATHSTAR project. The goal of the project is to reduce the uncertainties of observational estimates of mass-loss rates from Asymptotic Giant Branch (AGB) stars. Line emission from 12CO J=2-1 and 3-2…
The literature is rich in analysis and results related to thermally pulsing-asymptotic giant branch (TP-AGB) stars, but the problem of the instabilities that arise and cause the divergence of models during the late stages of their evolution…
We present new Spitzer/IRAC observations of 55 dusty Long Period Variables (LPVs, 48 AGB and 6 RSG stars) in the Galaxy that have different chemistry, variability type, and mass-loss rate. O-rich AGB stars (including intrinsic S-type) tend…
The evolution and lifetimes of thermally pulsating asymptotic giant branch (TP-AGB) stars suffer from significant uncertainties. We present a detailed framework for constraining model luminosity functions of TP-AGB stars using resolved…
Dust formation and resulting mass loss around Asymptotic Giant Branch (AGB) stars with initial metallicity in the range of $0 \leq Z_{\rm ini} \leq 10^{-4}$ and initial mass $2\leq M_{\rm ini}/M_{\odot} \leq 5$ are explored by the…
Although most white dwarf stars have hydrogen-dominated atmospheres, a significant fraction have atmospheres in which hydrogen is spectroscopically absent, with the fraction of hydrogen-free atmospheres varying with effective temperature.…
Winds of asymptotic giant branch (AGB) stars are commonly assumed to be driven by radiative acceleration of dust grains. For M-type AGB stars, the nature of the wind-driving dust species has been a matter of intense debate. A proposed…
I discuss the relationship between mass loss and nucleosynthesis on the Asymptotic Giant Branch (AGB). Because of thermal pulses and possibly other mixing processes, products of nucleosynthesis can be brought to the surface of AGB stars,…
Mass loss on the Asymptotic Giant Branch provides the origin of planetary nebulae. This paper reviews several relevant aspects of AGB evolution: pulsation properties, mass loss formalisms and time variable mass loss, evidence for…
Asymptotic giant branch (AGB) stars lose their envelopes by means of a stellar wind whose driving mechanism is not understood well. Characterizing the composition and thermal and dynamical structure of the outflow provides constraints that…
We investigate the population of cool, evolved stars in the Local Group dwarf elliptical galaxy M32, using Infrared Array Camera observations from the Spitzer Space Telescope. We construct deep mid-infrared colour-magnitude diagrams for the…
AGB stars, the precursors of Planetary Nebulae, exhibit high rates of mass loss and eject material in the form of a slow (10-20 km/s), dusty molecular wind. The general belief that the dust component of AGB circumstellar envelopes have…
In 1981, the idea of a superwind that ends the life of cool giant stars was proposed. Extreme OH/IR-stars develop superwinds with the highest mass-loss rates known so far, up to a few 10^(-4) Msun/yr, informing our understanding of the…
The S-type stars are believed to have a C/O-ratio close to unity (within a few percent). They are considered to represent an intermediate evolutionary stage as AGB stars evolve from oxygen-rich M-type stars into carbon stars. As possible…