scholarly journals Mass-loss on the red giant branch: the value and metallicity dependence of Reimers’ η in globular clusters

2015 ◽  
Vol 448 (1) ◽  
pp. 502-521 ◽  
Author(s):  
I. McDonald ◽  
A. A. Zijlstra
Keyword(s):  
Mass Loss ◽  
Globular Clusters ◽  
Red Giant

scholarly journals Is Mass Loss Along the Red Giant Branch of Globular Clusters Sharply Peaked? The Case of M3

2008 ◽  
Vol 673 (2) ◽  
pp. 847-853 ◽  
Author(s):  
Vittoria Caloi ◽  
Francesca D’Antona
Keyword(s):  
Mass Loss ◽  
Globular Clusters ◽  
Red Giant

scholarly journals Mass-loss law for red giant stars in simple population globular clusters

2021 ◽  
Vol 503 (1) ◽  
pp. 694-703
Author(s):  
M Tailo ◽  
A P Milone ◽  
E P Lagioia ◽  
F D’Antona ◽  
S Jang ◽  
...  
Keyword(s):  
Mass Loss ◽  
Stellar Evolution ◽  
Globular Clusters ◽  
Hubble Space Telescope ◽  
Stellar Populations ◽  
Chemical Compositions ◽  
Multiple Populations ◽  
Mass Losses ◽  
Red Giant ◽  
Stellar Masses

ABSTRACT The amount of mass lost by stars during the red-giant branch (RGB) phase is one of the main parameters to understand and correctly model the late stages of stellar evolution. Nevertheless, a fully comprehensive knowledge of the RGB mass-loss is still missing. Galactic Globular Clusters (GCs) are ideal targets to derive empirical formulations of mass-loss, but the presence of multiple populations with different chemical compositions has been a major challenge to constrain stellar masses and RGB mass-losses. Recent work has disentangled the distinct stellar populations along the RGB and the horizontal branch (HB) of 46 GCs, thus providing the possibility to estimate the RGB mass-loss of each stellar population. The mass-losses inferred for the stellar populations with pristine chemical composition (called first-generation or 1G stars) tightly correlate with cluster metallicity. This finding allows us to derive an empirical RGB mass-loss law for 1G stars. In this paper, we investigate seven GCs with no evidence of multiple populations and derive the RGB mass-loss by means of high-precision Hubble-Space Telescope photometry and accurate synthetic photometry. We find a cluster-to-cluster variation in the mass-loss ranging from ∼0.1 to ∼0.3 M⊙. The RGB mass-loss of simple-population GCs correlates with the metallicity of the host cluster. The discovery that simple-population GCs and 1G stars of multiple population GCs follow similar mass-loss versus metallicity relations suggests that the resulting mass-loss law is a standard outcome of stellar evolution.

ISOCAM Observations of Galactic Globular Clusters: Mass Loss along the Red Giant Branch

2002 ◽  
Vol 571 (1) ◽  
pp. 458-468 ◽  
Author(s):  
Livia Origlia ◽  
Francesco R. Ferraro ◽  
Flavio Fusi Pecci ◽  
Robert T. Rood
Keyword(s):  
Mass Loss ◽  
Globular Clusters ◽  
Galactic Globular Clusters ◽  
Red Giant

scholarly journals Mass-loss along the red giant branch in 46 globular clusters and their multiple populations

2020 ◽  
Vol 498 (4) ◽  
pp. 5745-5771
Author(s):  
M Tailo ◽  
A P Milone ◽  
E P Lagioia ◽  
F D’Antona ◽  
A F Marino ◽  
...  
Keyword(s):  
Mass Loss ◽  
Globular Clusters ◽  
First Generation ◽  
Hubble Space Telescope ◽  
Population Synthesis ◽  
Data Set ◽  
Complex Interactions ◽  
The Difference ◽  
Red Giant ◽  
First Time

ABSTRACT The location of Galactic globular clusters’ (GC) stars on the horizontal branch (HB) should mainly depend on GC metallicity, the ‘first parameter’, but it is actually the result of complex interactions between the red giant branch (RGB) mass-loss, the coexistence of multiple stellar populations with different helium content, and the presence of a ‘second parameter’ that produces dramatic differences in HB morphology of GCs of similar metallicity and ages (like the pair M3–M13). In this work, we combine the entire data set from the Hubble Space Telescope Treasury survey and stellar evolutionary models, to analyse the HBs of 46 GCs. For the first time in a large sample of GCs, we generate population synthesis models, where the helium abundances for the first and the ‘extreme’ second generations are constrained using independent measurements based on RGB stars. The main results are as follows: (1) The mass-loss of first-generation stars is tightly correlated to cluster metallicity. (2) The location of helium enriched stars on the HB is reproduced only by adopting a higher RGB mass-loss than for the first generation. The difference in mass-loss correlates with helium enhancement and cluster mass. (3) A model of ‘pre-main sequence disc early loss’, previously developed by the authors, explains such a mass-loss increase and is consistent with the findings of multiple-population formation models predicting that populations more enhanced in helium tend to form with higher stellar densities and concentrations. (4) Helium-enhancement and mass-loss both contribute to the second parameter.

scholarly journals STELLAR ENCOUNTER DRIVEN RED-GIANT STAR MASS LOSS IN GLOBULAR CLUSTERS

2014 ◽  
Vol 789 (1) ◽  
pp. 28 ◽  
Author(s):  
Mario Pasquato ◽  
Andrea de Luca ◽  
Gabriella Raimondo ◽  
Roberta Carini ◽  
Anthony Moraghan ◽  
...  
Keyword(s):  
Mass Loss ◽  
Globular Clusters ◽  
Giant Star ◽  
Star Mass ◽  
Red Giant

scholarly journals Discovery of Infrared Stars in Globular Clusters in the Magellanic Clouds and Their Light Variations

1998 ◽  
Vol 11 (1) ◽  
pp. 395-395
Author(s):  
S. Nishida ◽  
T. Tanabé ◽  
S. Matsumoto ◽  
T. Onaka ◽  
Y. Nakada ◽  
...  
Keyword(s):  
Mass Loss ◽  
Globular Clusters ◽  
Main Sequence ◽  
Near Infrared ◽  
Magellanic Clouds ◽  
Infrared Light ◽  
Agb Stars ◽  
Dust Shells ◽  
Infrared Stars ◽  
Infrared Survey

A systematic near-infrared survey was made for globular clusters in the Magellanic Clouds. Two infrared stars were discovered in NGC419 (SMC) and NGC1783 (LMC). NGC419 and NGC1783 are well-studied rich globular clusters whose turn-off masses and ages are estimated MTO ~ 2.0 Mʘ and т ~1.2 Gyr for NGC419, and MT0 ~ 2.0 Mʘ and т ʘ 0.9 Gyr for NGC1783, respectively. The periods of the infrared light variations were determined to be 540 dfor NGC419IR1 and to be 480 d for NGC1783IR1, respectively. Comparison of the measurements with the period—if magnitude relation for carbon Miras in the LMC by Groenewegen and Whitelock(1996) revealed that the Kmagnitudes of the infrared stars were fainter by about 0.3 — 0.8 magnitude than those predicted by the P — K relation. This deviation can be explained if the infrared stars are surrounded by thick dust shells and are obscured even in the K band. The positions of NGC419IR1and NGC1783IR1 on the P — K diagram suggest that AGB stars with the main sequence masses of about 2 Mʘ start their heavy mass-loss when P ʘ 500 d.

scholarly journals Asteroseismology of luminous red giants with Kepler. II. Dependence of mass loss on pulsations and radiation

2020 ◽  
Author(s):  
Jie Yu ◽  
Saskia Hekker ◽  
Timothy R Bedding ◽  
Dennis Stello ◽  
Daniel Huber ◽  
...  
Keyword(s):  
Mass Loss ◽  
Mass Loss Rate ◽  
Asymptotic Giant Branch ◽  
Red Giants ◽  
Asymptotic Giant Branch Stars ◽  
Chemical Enrichment ◽  
Dust Mass ◽  
Red Giant ◽  
The Masses ◽  
Loss Rates

Abstract Mass loss by red giants is an important process to understand the final stages of stellar evolution and the chemical enrichment of the interstellar medium. Mass-loss rates are thought to be controlled by pulsation-enhanced dust-driven outflows. Here we investigate the relationships between mass loss, pulsations, and radiation, using 3213 luminous Kepler red giants and 135000 ASAS–SN semiregulars and Miras. Mass-loss rates are traced by infrared colours using 2MASS and WISE and by observed-to-model WISE fluxes, and are also estimated using dust mass-loss rates from literature assuming a typical gas-to-dust mass ratio of 400. To specify the pulsations, we extract the period and height of the highest peak in the power spectrum of oscillation. Absolute magnitudes are obtained from the 2MASS Ks band and the Gaia DR2 parallaxes. Our results follow. (i) Substantial mass loss sets in at pulsation periods above ∼60 and ∼100 days, corresponding to Asymptotic-Giant-Branch stars at the base of the period-luminosity sequences C′ and C. (ii) The mass-loss rate starts to rapidly increase in semiregulars for which the luminosity is just above the red-giant-branch tip and gradually plateaus to a level similar to that of Miras. (iii) The mass-loss rates in Miras do not depend on luminosity, consistent with pulsation-enhanced dust-driven winds. (iv) The accumulated mass loss on the Red Giant Branch consistent with asteroseismic predictions reduces the masses of red-clump stars by 6.3%, less than the typical uncertainty on their asteroseismic masses. Thus mass loss is currently not a limitation of stellar age estimates for galactic archaeology studies.

scholarly journals Light element abundance inhomogeneities in globular clusters: probing star formation and evolution in the early Milky Way

1994 ◽  
Vol 72 (11-12) ◽  
pp. 772-781 ◽  
Author(s):  
Michael M. Briley ◽  
Roger A. Bell ◽  
James E. Hesser ◽  
Graeme H. Smith
Keyword(s):  
Star Formation ◽  
Globular Clusters ◽  
Main Sequence ◽  
Light Element ◽  
Star Formation History ◽  
Element Abundance ◽  
Chemical Compositions ◽  
Original Material ◽  
Abundance Patterns ◽  
Red Giant

Abundance patterns of the elements C, N, and O are sensitive probes of stellar nucleosynthesis processes and, in addition, O abundances are an important input for stellar age determinations. Understanding the nature of the observed distribution of these elements is key to constraining protogalactic star formation history. Patterns deduced from low-resolution spectroscopy of the CN, CH, NH, and CO molecules for low-mass stars in their core-hydrogen or first shell-hydrogen burning phases in the oldest ensembles known, the Galactic globular star clusters, are reviewed. New results for faint stars in NGC 104 (47 Tuc, C0021-723) reveal that the bimodal, anticorrelated pattern of CN and CH strengths found among luminous evolved stars is also present in stars nearing the end of their main-sequence lifetimes. In the absence of known mechanisms to mix newly synthesized elements from the interior to the observable surface layers of such unevolved stars, those particular inhomogeneities imply that the original material from which the stars formed some 15 billion years ago was chemically inhomogeneous in the C and N elements. However, in other clusters, observations of abundance ratios and C isotope ratios suggest that alterations to surface chemical compositions are produced as stars evolve from the main sequence through the red giant branch. Thus, the current observed distributions of C, N, and O among the brightest stars (those also observed most often) may not reflect the true distribution from which the protocluster cloud formed. The picture that is emerging of the C, N, and O abundance patterns within globular clusters may be one which requires a complicated combination of stellar evolutionary and primordial effects for its explanation.

scholarly journals Chemical composition and constraints on mass loss for globular clusters in dwarf galaxies: WLM and IKN

2014 ◽  
Vol 565 ◽  
pp. A98 ◽  
Author(s):  
Søren S. Larsen ◽  
Jean P. Brodie ◽  
Duncan A. Forbes ◽  
Jay Strader
Keyword(s):  
Chemical Composition ◽  
Mass Loss ◽  
Globular Clusters ◽  
Dwarf Galaxies
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