Related papers: AGB Stars in WLM
The initial conditions for the mass loss during the asymptotic giant branch (AGB) phase are set in their extended atmospheres, where, among others, convection and pulsation driven shocks determine the physical conditions. High resolution…
JHKs photometry is presented from a three-year survey of the central regions of the Local Group dwarf irregular galaxy IC1613. The morphologies of the colour-magnitude and colour-colour diagrams are discussed with particular reference to…
The study of the evolutionary properties of Asymptotic Giant Branch stars still presents unresolved topics. Progress in the theoretical understanding of their evolution is hampered by the difficulty to empirically explain key physical…
We present spectroscopic data for 180 red giant branch stars in the isolated dwarf irregular galaxy WLM. Observations of the Calcium II triplet lines in spectra of RGB stars covering the entire galaxy were obtained with FORS2 at the VLT and…
We present asymptotic giant branch (AGB) models of solar metallicity, to allow the interpretation of observations of Galactic AGB stars, whose distances should be soon available after the first release of the Gaia catalogue. We find an…
Dwarf irregular galaxies are unique laboratories for studying the interaction between stars and the interstellar medium in low mass environments. We present the highest spatial resolution observations to date of the neutral hydrogen content…
We present the preliminary results of a wide-field photometric survey of individual red giant branch (RGB) and asymptotic giant branch (AGB) stars in the M81 group, performed with the CFH12K mosaic camera of the CFHT. We use deep VI images…
It is now about 30 years ago that photometric and spectroscopic surveys of asymptotic giant branch (AGB) stars in the Magellanic Clouds (MCs) uncovered the first examples of truly massive (> 3-4 M_s) O-rich AGB stars experiencing hot bottom…
I present a selection of results obtained from VLT FORS1 and ISAAC photometric monitoring of late-type giants in NGC 5128 (=Centaurus A). The combination of optical and near-IR photometry allows to probe the full metallicity range of the…
Multiple stellar populations (MPs) are a distinct characteristic of Globular Clusters (GCs). Their general properties have been widely studied among main sequence, red giant branch (RGB) and horizontal branch (HB) stars, but a common…
IC 10 as a starburst dwarf galaxy in the Local Group (LG) has a large population of newly formed stars that are massive and intrinsically very bright in comparison with other LG galaxies. Using the Isaac Newton Telescope (INT) with the Wide…
Recent morphological studies of galaxies by the {\it Hubble Space Telescope (HST)} have revealed that actively star-forming galaxies at intermediate and high redshifts ($z=0.5-2.0$) have very clumpy and irregular distributions of stars. It…
We discuss the tracing of star formation histories with ESA's space astrometry mission GAIA, emphasizing the advantages of AGB stars for this purpose. GAIA's microarcsecond-level astrometry, multi-band photometry and spectroscopy will…
Aims: We calibrate spectroscopically the C- versus (vs.) M-type asymptotic giant branch (AGB) star selection made using near-IR photometry, and investigate the spatial distribution of the C/M ratio in NGC 6822, based on low resolution…
Stellar light from an AGB star is scattered by the circumstellar dust and polarized in the direction perpendicular to the source. Therefore, images of circumstellar envelopes around AGB stars in polarized light traces the dust distribution…
The distance, star formation history and global properties of the Local Group dIrr galaxy SagDIG are derived based on an [I-(V-I)] colour--magnitude diagram of ~1550 stars. A distance of 1.06+/-0.10 Mpc is obtained from the I magnitude of…
We present 12CO J = 1-0 and J = 2-1 observations of the low metallicity (12 + log(O/H) = 7.74) Local Group dwarf irregular galaxy WLM made with the 15 m SEST and 14 m FCRAO telescopes. Despite the presence a number of HII regions, we find…
We present the first results of our ongoing chemical study of carbon stars in the Local Group of galaxies. We used spectra obtained with UVES at the 8.2 m Kueyen-VLT telescope and a new grid of spherical model atmospheres for cool…
Context. Extremely reddened AGB stars lose mass at high rates of >10^-5 Msun/yr. This is the very last stage of AGB evolution, in which stars in the mass range 2.0--4.0 Msun (for solar metallicity) should have been converted to C stars…
We report the first gas-phase metallicity map of a distant galaxy measured with the James Webb Space Telescope (JWST). We use the NIRISS slitless spectroscopy acquired by the GLASS Early Release Science program to spatially resolve the…