相关论文: Probing clumpy pasts of galaxies from AGB stars

The evolution of galaxies is driven by the birth and death of stars. AGB stars are at the end points of their evolution and therefore their luminosities directly reflect their birth mass; this enables us to reconstruct the star formation…

We have traced the spatial distributions of intermediate-age and old stars in nine dwarf galaxies in the distant parts of the Local Group, using multi-epoch 3.6 and 4.5 micron data from the DUST in Nearby Galaxies with Spitzer (DUSTiNGS)…

Context: The environmental conditions for asympotic giant branch (AGB) stars to reach the carbon-rich (C-rich) phase are important to understand the evolutionary process of AGB stars. The difference between the spatial distributions of…

We calculated theoretical evolutionary sequences of asymptotic giant branch (AGB) stars, including formation and evolution of dust grains in their circumstellar envelope. By considering stellar populations of the Large Magellanic Cloud…

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…

The Thermally-Pulsating Asymptotic Giant Branch (TP-AGB) phase of stellar evolution has received attention only recently in galaxy evolution, but is now an important player in our understanding of how galaxies form and evolve. Because it is…

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…

Galaxies above redshift 1 can be very clumpy, with irregular morphologies dominated by star complexes as large as 2 kpc and as massive as a few 10^8 or 10^9 Mo. Their co-moving densities and rapid evolution suggest that most present-day…

Luminous compact blue galaxies (LCBGs) have enhanced star formation rates and compact morphologies. We combine Sloan Digital Sky Survey data with HI data of 29 LCBGs at redshift z~0 to understand their nature. We find that local LCBGs have…

A review is presented of the most relevant results obtained in the last few years on this rare class of astronomical sources. Multi-wavelength analysis of an increasing number of post-AGB stars reveal that they constitute a more…

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…

Clumpy galaxies in the GEMS and GOODS fields are examined for clues to their evolution into modern spirals. The magnitudes of the clumps and the surface brightnesses of the interclump regions are measured and fitted to models of stellar age…

We report the results of an exploratory program to image the extended circumstellar envelopes of asymptotic giant branch (AGB) stars in dust-scattered galactic light. The goal is to characterize the morphology of the envelopes as a probe of…

A previously reported literature search suggested that the AGB stars in Galactic globular clusters may be showing different distributions of CN-strong and CN-weak stars as compared to their RGB stars. In most cases the second giant branches…

The majority of the inhomogeneities in the chemical composition of Globular Cluster (GC) stars appear due to primordial enrichment. The most studied model today claims that the ejecta of Asymptotic Giant Branch (AGB) stars of high mass…

While the basic properties of AGB stellar evolution are well established, comprehensive observational studies of late phases of intermediate mass stars continue to generate puzzles for current stellar models. Here, I review current…

During their thermally pulsing phase, Asymptotic Giant Branch (AGB) stars eject material that forms extended dusty envelopes. Visible polarimetric imaging found clumpy dust clouds within two stellar radii of several oxygen-rich stars.…

The formation of silicates in circumstellar envelopes of stars evolving through the AGB is still debated given the uncertainties affecting stellar evolution modelling, the description of the dust formation process, and the capability of…

The huge photometric databases that are being created for stars in the Magellanic Clouds and in Local Group galaxies not only allow detailed study of the star formation history of these systems, but also provide important information on…

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…