On convective and semiconvective mixing in massive stars

Cloutman, L.D.; Whitaker, Rodney W.

doi:10.1086/157937

Cited by 28 publications

(10 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Among others, suffice it to recall here the so-called mass discrepancy of Cepheid stars (Bertelli et al 1986b;Chiosi et al 1992). The first studies of this subject were by Shaviv & Salpeter (1973); Prather & Demarque (1974);Maeder (1975); Cloutman & Whitaker (1980b); Bressan et al (1981); Stothers & Chin (1981), followed over the years by more sophisticated formulations standing on turbulence theories (Cloutman & Whitaker 1980a;Xiong 1980) and fluid hydrodynamics (Canuto & Mazzitelli 1991;Canuto et al 1996;Unno & Kondo 1989;Canuto 2000). The ballistic description long ago proposed by Bressan et al (1981) is particularly suitable for the calculation of stellar models.…”

Section: Revisiting An Old Question: Convective Overshootmentioning

confidence: 99%

Three clusters of the SMC from ACS/WFC HST archive data: NGC 265, K 29 and NGC 290 and their field population

Chiosi

Vallenari

2007

A&A

View full text Add to dashboard Cite

Aims. We determine the age, metallicity and initial mass function of three clusters, namely NGC 265, K 29, NGC 290, located in the main body of the Small Magellanic Cloud. In addition, we derive the history of star formation in the companion fields. Methods. We make use of ACS/WFC HST archive data. For the clusters, the age and metallicity are derived fitting the integrated luminosity function with single synthetic stellar population by means of the χ 2 minimization. For the companion fields, the history of star formation is derived using the χ 2 minimization together with the downhill-simplex method. Results. For the clusters we find the following ages and metallicities: NGC 265 has log(Age) = 8.5 ± 0.3 yr and metallicity 0. The comparison of the NGC 265 luminosity function with the theoretical ones from stellar models both taking overshoot from the convective core into account and neglecting it, seems to suggest that a certain amount of convective overshoot is required. However, this conclusion is not a strong one because this cluster has a certain amount of mass segregation which makes it difficult to choose a suitable area for this comparison. The star formation rate of the field population presents periods of enhancements at 300−400 Myr, 3−4 Gyr and finally 6 Gyr. However it is relatively quiescent at ages older than 6 Gyr. This result suggests that at older ages, the tidal interaction between the Magellanic Clouds and the Milky Way was not able to trigger significant star formation events.

show abstract

Section: Revisiting An Old Question: Convective Overshootmentioning

confidence: 99%

Three clusters of the SMC from ACS/WFC HST archive data: NGC 265, K 29 and NGC 290 and their field population

Chiosi

Vallenari

2007

A&A

View full text Add to dashboard Cite

show abstract

“…This uncertainty is reflected in the variety of solutions and evolutionary models that have been proposed over the years. Major contributions to this subject in the past were from Shaviv & Salpeter (1973), Prather & Demarque (1974), Maeder (1975), Cloutman & Whitaker (1980), Bressan et al (1981), Stothers & Chin (1981). See Chiosi (1998) for an exhaustive review for the understanding of the HR diagrams and for references on convection, overshoot and related stellar models.…”

Section: Convective Overshootmentioning

confidence: 99%

Testing Intermediate-Age Stellar Evolution Models with VLT Photometry of Large Magellanic Cloud Clusters. III. Padova Results

Bertelli

Nasi

Girardi

et al. 2003

The Astronomical Journal

View full text Add to dashboard Cite

The color-magnitude diagrams (CMDs) of three intermediate-age LMC clusters, NGC 2173, SL556 and NGC2155 are analyzed to determine their age and metallicity basing on Padova stellar models. Synthetic CMDs are compared with cluster data. The best match is obtained using two fitting functions based on star counts in the different bins of the cluster CMD. Two different criteria are used. One of them takes into account the uncertainties in the color of the red clump stars. Given the uncertainties on the experimental values of the clusters metallicity, we provide a set of acceptable solutions. They define the correspondent values of metallicity, age, reddening and distance modulus (for the assumed IMF). The comparison with Padova models suggests for NGC 2173 a prolonged star formation (spanning a period of about 0.3 Gyr), beginning 1.7 Gyr and ending 1.4 Gyr ago. The metallicity Z is in the range 0.0016 − 0.003. Contrary to what suggested for NGC 2173, a period of extended star formation was not required to fit the SL 556 and the NGC 2155 observations. For SL 556 an age of 2.0 Gyr is obtained. The metallicity value is in the range 0.002 − 0.004, depending on the adopted comparison criterium. The derived age for NGC 2155 is 1 Based on observations collected at the European Southern Observatory, 2.8 Gyr and its metallicity Z is in the range 0.002 − 0.003. The CMD features of this cluster suggest that a more efficient overshoot should be adopted in the evolutionary models.

show abstract

“…The present work is mainly focused on the empirical side of the study of convective overshooting. However, early theoretical studies (Roxburgh 1965, 1978; Saslaw & Schwarzschild 1965; Shaviv & Salpeter 1973; Maeder 1975; Cogan 1975; Massevitch et al 1979; Cloutman & Whitaker 1980; Bressan, Bertelli & Chiosi 1981) have already approached this issue and found values of α ov between 0 and 2.…”

Section: Introductionmentioning

confidence: 99%

The mass dependence of the overshooting parameter determined from eclipsing binary data

Ribas

Jordi

Giménez

2000

Monthly Notices of the Royal Astronomical Society

143

144

View full text Add to dashboard Cite

A B S T R A C THigh-precision data on absolute dimensions of evolved eclipsing binaries have been used for a quantitative evaluation of the significance of convective overshoot in the stellar core. Eight detached double-lined eclipsing binaries with components close to or beyond the terminal age main sequence (TAMS) and masses between 2 and 12 M ( have been compared with evolutionary models using different overshooting parameters. The results are robust and indicate a systematic increase of the amount of convective overshoot with the stellar mass. Such determination constitutes a fundamental point for stellar structure and evolution theory.

show abstract

On convective and semiconvective mixing in massive stars

Cited by 28 publications

References 0 publications

Three clusters of the SMC from ACS/WFC HST archive data: NGC 265, K 29 and NGC 290 and their field population

Three clusters of the SMC from ACS/WFC HST archive data: NGC 265, K 29 and NGC 290 and their field population

Testing Intermediate-Age Stellar Evolution Models with VLT Photometry of Large Magellanic Cloud Clusters. III. Padova Results

The mass dependence of the overshooting parameter determined from eclipsing binary data

Contact Info

Product

Resources

About