Related papers: Can star cluster environment affect dust input fro…
We have employed state-of-the-art evolutionary models of low and intermediate-mass AGB stars, and included the effect of circumstellar dust shells on the spectral energy distribution (SED) of AGB stars, to revise the Padua library of…
Benefiting from the GAIA second and early third releases of photometric and astrometric data we examine the population of asymptotic giant branch (AGB) stars that appear in the fields of intermediate-age and young open star clusters. We…
A large fraction of stars forming in our galaxy are born within clusters embedded in giant molecular clouds. In these environments, the background UV radiation fields impinging upon circumstellar disks can often dominate over the radiation…
The study of post asymptotic giant branch (post-AGB) stars is a valuable tool to study still poorly known aspects of the evolution of the stars through the AGB. This is due to the accurate determination of their surface chemical composition…
Low- and intermediate-mass stars are one of the important dust sources in the interstellar medium (ISM) of galaxies. The compositions of dust ejected from these stars are likely to affect those in the ISM. We investigate dust in…
We present new models for the evolution of stars with mass in the range 1Msun < M < 7.5Msun, followed from the pre-main-sequence through the asymptotic giant branch phase. The metallicity adopted is $Z=3*10^{-4} (which, with an…
We measure the integrated contributions of dusty AGB stars and other luminous red mid-IR sources to the mid-IR luminosities of 6 galaxies (M81, NGC 2403, NGC 300, M33 and the Magellanic Clouds). We find the dusty AGB stars whose mid-IR…
The lifecycle of dust in the interstellar medium (ISM) is heavily influenced by outflows from asymptotic giant branch (AGB) and red supergiant (RSG) stars, a large fraction of which is contributed by a few very dusty sources. We compute the…
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…
The heavy mass loss observed in evolved asymptotic giant branch stars is usually attributed to a two-step process: atmospheric levitation by pulsation-induced shock waves, followed by radiative acceleration of newly formed dust grains.…
The asymptotic giant branch (AGB) phase is the penultimate stage of evolution for low- and intermediate-mass stars. AGB star outflows inject a significant amount of material into the interstellar medium (ISM), seeding new star formation.…
We calculate the dust formed around AGB and SAGB stars of metallicity Z=0.008 by following the evolution of models with masses in the range 1M<M<8M throughthe thermal pulses phase, and assuming that dust forms via condensation of molecules…
Dust grains forming in the extended atmospheres of AGB stars are critical for the heavy mass loss of these cool luminous giants, as they provide radiative acceleration for the stellar winds. Characteristic mid-IR spectral features indicate…
An analysis of high-resolution near-infrared spectra of a sample of 45 asymptotic giant branch (AGB) stars towards the Galactic bulge is presented. The sample consists of two subsamples, a larger one in the inner and intermediate bulge, and…
This thesis is aimed at clarifying one of the least studied phases of stellar evolution: the asymptotic giant branch (AGB). Recent results obtained for Galactic globular clusters (GCs) suggest that the AGB stage may contain crucial…
With the aim of investigating whether stellar sources can account for the >10^8 Msun dust masses inferred from mm/sub-mm observations of samples of 5<z<6.4 quasars,we develop a chemical evolution model which follows the evolution of metals…
We aim to constrain the dust mass and grain sizes in the interaction regions between the stellar winds and the ISM around asymptotic giant branch stars. By describing the dust in these regions, we aim to shed light on the role of low mass…
The evolution of AGB stars is notoriously complex. The confrontation of AGB population models with observed stellar populations is a useful alternative to the detailed study of individual stars in efforts to converge towards a reliable…
We demonstrate that a massive asymptotic giant branch (AGB) star is a good candidate as the main source of short-lived radionuclides in the early solar system. Recent identification of massive (4-8 solar masses) AGB stars in the Galaxy,…
To study the nature of Bulge AGB stars and in particular their circumstellar dust, we have analysed mid-infrared spectra obtained with the ISOCAM CVF spectrometer in three Bulge fields. The ISOCAM 5-16.5 micron CVF spectra were obtained as…