The bottleneck of CNO burning and the age of Globular Clusters

Imbriani, G.; Costantini, H.; Formicola, A.; Bemmerer, D.; Bonetti, R.; Broggini, C.; Corvisiero, P.; Cruz, J.; Fülöp, Zsolt; Gervino, G.; Guglielmetti, A.; Gustavino, C.; Gyürky, Gy.; Jesus, A.P.; Junker, M.; Lemut, A.; Menegazzo, R.; Prati, P.; Roca, V.; Rolfs, C.; Romano, M.; Alvarez, C. Rossi; Schümann, F.; Somorjai, E.; Straniero, O.; Strieder, F.; Terrasi, F.; Trautvetter, H. P.; Vomiero, Alberto; Zavatarelli, S.

doi:10.1051/0004-6361:20040981

Cited by 155 publications

(120 citation statements)

References 24 publications

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“…The tracks obtained with the CF88 rate practically coincide with those obtained with the NACRE rate, as shown by Imbriani et al (2004). The LUNA rate was simulated by simply multiplying that of Caughlan & Fowler by a factor of 0.6 (LUNA Collaboration, Bemmerer et al 2006;Imbriani et al 2005;Lemut et al 2006).…”

Section: Nuclear Reaction Ratessupporting

confidence: 52%

Scaled solar tracks and isochrones in a large region of theZ–Yplane

Bertelli¹,

Nasi²,

Girardi³

et al. 2009

A&A

252

348

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We extend our theoretical computations for low-mass stars to intermediate-mass and massive stars, for which few databases exist in the literature. Evolutionary tracks and isochrones are computed for initial masses 2.50−20 M for a grid of 37 chemical compositions with metal content Z between 0.0001 and 0.070 and helium content Y between 0.23 and 0.40 to enable users to obtain isochrones for ages as young as about 10 7 years and to simulate stellar populations with different helium-to-metal enrichment laws. The Padova stellar evolution code is identical to that used in the first paper of this series. Synthetic TP-AGB models allow stellar tracks and isochrones to be extended until the end of the thermal pulses along the AGB. We provide software tools for the bidimensional interpolation (in Y and Z) of the isochrones from very old ages down to about 10 7 years. This lower limit depends on chemical composition. The extension of the blue loops and the instability strip of Cepheid stars are compared and the Cepheid mass-discrepancy is discussed. The location of red supergiants in the H-R diagram is in good agreement with the evolutionary tracks for masses from 10 to 20 M . Tracks and isochrones are available in tabular form for the adopted grid of chemical compositions in the extended plane Z − Y in three photometric systems. An interactive web interface allows users to obtain isochrones of any chemical composition inside the provided Z − Y range and also to simulate stellar populations with different Y(Z) helium-to-metal enrichment laws.

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Section: Nuclear Reaction Ratessupporting

confidence: 52%

Scaled solar tracks and isochrones in a large region of theZ–Yplane

Bertelli¹,

Nasi²,

Girardi³

et al. 2009

A&A

252

348

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“…Weiss et al (2005) investigated the effect of this new reaction rate on the evolution of both low-and intermediate-mass stars. They confirmed the results obtained by Imbriani et al (2004) and extended their analysis to more advanced evolutionary stages such as the He-burning ignition at the red giant branch (RGB) tip in low-mass stars, and the core and shell He-burning stages in intermediate mass stars. Magic et al (2010) highlighted the crucial role played by the 14 N(p, γ) 15 O reaction rate in determining the transition mass to stars harbouring a convective core.…”

Section: Introductionsupporting

confidence: 80%

“…Because of the significant impact of the revised reaction rate on the efficiency of the CNO cycle, hence on the age -luminosity calibration during the late MS evolution, Imbriani et al (2004) studied its effect on the age dating of Galactic globular clusters (GCs). Their analysis has shown that the new rate for the 14 N(p, γ) 15 O reaction leads to isochrones with a brighter and hotter turn off (TO) for a fixed age, and the resulting age -TO luminosity calibration predicts on average systematically older GC ages by ∼0.9 Gyr.…”

Section: Introductionmentioning

confidence: 99%

The impact of an updated¹⁴N(p,γ)¹⁵O reaction rate on advanced evolutionary stages of low-mass stellar models

Pietrinferni

Cassisi

Salaris

2010

A&A

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We investigate the impact of the 14 N(p, γ) 15 O reaction rate as redetermined by the LUNA experiment, on the shell H-burning and core He-burning phases of low-mass, metal-poor stellar models. The new reaction rate has small but noticeable effects, the largest one being a ∼7−8% reduction in the red giant branch lifetimes. To different degrees, the lifetimes and luminosities of horizontal branch models, the mass of the stellar models evolving within the RR Lyrae instability strip, the luminosity of the red giant branch luminosity function bump, the theoretical calibrations of the R-parameter, and the tip of the red giant branch luminosity are also affected. Predictions for the tip of the red giant branch luminosity, in particular, are in very good agreement with the currently available empirical constraints.

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“…DSEP08 use the old LUNA 14 N(p, γ) 15 O reaction rate (Imbriani et al 2004), which is about 6% greater than the latest LUNA release adopted in FRANEC. This difference would make the DSEP08 model colder than ours by about 20 K. Adding to this the other differences in the physical inputs adopted by DSEP08 with respect to FRANEC (i.e.…”

Section: Comparison With Different Authorsmentioning

confidence: 99%

The Pisa pre-main sequence tracks and isochrones

Tognelli

Moroni

Degl’Innocenti

2011

A&A

272

419

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Context. In recent years new observations of pre-main sequence stars (pre-MS) with Z ≤ Z have been made available. To take full advantage of the continuously growing amount of data of pre-MS stars in different environments, we need to develop updated pre-MS models for a wide range of metallicity to assign reliable ages and masses to the observed stars. Aims. We present updated evolutionary pre-MS models and isochrones for a fine grid of mass, age, metallicity, and helium values. Methods. We use a standard and well-tested stellar evolutionary code (i.e. FRANEC), that adopts outer boundary conditions from detailed and realistic atmosphere models. In this code, we incorporate additional improvements to the physical inputs related to the equation of state and the low temperature radiative opacities essential to computing low-mass stellar models. Results. We make available via internet a large database of pre-MS tracks and isochrones for a wide range of chemical compositions (Z = 0.0002−0.03), masses (M = 0.2−7.0 M ), and ages (1−100 Myr) for a solar-calibrated mixing length parameter α (i.e. 1.68). For each chemical composition, additional models were computed with two different mixing length values, namely α = 1.2 and 1.9. Moreover, for Z ≥ 0.008, we also provided models with two different initial deuterium abundances. The characteristics of the models have been discussed in detail and compared with other work in the literature. The main uncertainties affecting theoretical predictions have been critically discussed. Comparisons with selected data indicate that there is close agreement between theory and observation.

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The bottleneck of CNO burning and the age of Globular Clusters

Cited by 155 publications

References 24 publications

Scaled solar tracks and isochrones in a large region of theZ–Yplane

Scaled solar tracks and isochrones in a large region of theZ–Yplane

The impact of an updated¹⁴N(p,γ)¹⁵O reaction rate on advanced evolutionary stages of low-mass stellar models

The Pisa pre-main sequence tracks and isochrones

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The bottleneck of CNO burning and the age of Globular Clusters

Cited by 155 publications

References 24 publications

Scaled solar tracks and isochrones in a large region of theZ–Yplane

Scaled solar tracks and isochrones in a large region of theZ–Yplane

The impact of an updated14N(p,γ)15O reaction rate on advanced evolutionary stages of low-mass stellar models

The Pisa pre-main sequence tracks and isochrones

Contact Info

Product

Resources

About

The impact of an updated¹⁴N(p,γ)¹⁵O reaction rate on advanced evolutionary stages of low-mass stellar models