Exploring circumstellar effects on the Li abundances in massive Galactic AGB stars

V. Pérez-Mesa; O. Zamora; D. A. García-Hernández; B. Plez; A. Manchado; A. I. Karakas; M. Lugaro

Exploring circumstellar effects on the Li abundances in massive Galactic AGB stars

V. Pérez-Mesa, O. Zamora, D. A. García-Hernández, B. Plez, A. Manchado, A. I. Karakas, M. Lugaro

School of Physics and Astronomy

Research output: Chapter in Book/Report/Conference proceeding › Conference Paper › Other

Abstract

We have explored the circumstellar effects on the Li abundance determination in a complete sample of O-rich Galactic asymptotic giant branch (AGB) stars, previously studied with hydrostatic models. We use a modified version of the spectral synthesis code Turbospectrum and more realistic extended model atmospheres that consider the presence of a gaseous circumstellar envelope and a radial wind in these massive AGB stars. The Li abundances are determined from the 6708 Å Li I resonance line. The Li pseudo-dynamical abundances obtained are practically identical to those derived with hydrostatic models (a maximum difference of 0.3 dex is found in the only super Li-rich AGB star in our sample). The low Li abundance and therefore negligible Li I column-density in the circumstellar envelope likely explains the small differences between extended and hydrostatic models. Our results confirm the activation of the hot bottom burning (HBB) process in massive Galactic AGB stars.

Original language	English
Title of host publication	Memorie della Societa Astronomica Italiana - Journal of the Italian Astronomical Society
Subtitle of host publication	2017 AGB-Supernovae Mass Transition; Monte Porzio Catone; Italy; 27 March 2017 through 31 March 2017
Editors	A Karakas, P Ventura, F Dell'Agli, M Di Criscienzo
Place of Publication	Italy
Pages	451-454
Number of pages	4
Volume	88
Edition	3
Publication status	Published - 2017
Event	The AGB-Supernovae Mass Transition 2017 - Observatory of Rome, Monte Porzio Catone, Italy Duration: 27 Mar 2017 → 31 Mar 2017 https://web.archive.org/web/20170111030144/http://agb-supernovae.weebly.com:80/ https://agb-supernovae.weebly.com/

Publication series

Name	Memorie della Società Astronomica Italiana
Publisher	Società Astronomica Italiana
ISSN (Print)	0037-8720

Conference

Conference	The AGB-Supernovae Mass Transition 2017
Country/Territory	Italy
City	Monte Porzio Catone
Period	27/03/17 → 31/03/17
Other	Little is known about stars in the mass range between those that end their lives as white dwarfs and those that die in spectacular supernova explosions. The uncertainty stems from the fact that stars in this transition mass range from about ~7 to 11 solar masses are both difficult to model theoretically and there are few observational clues as to their evolutionary history. Following the ignition of carbon in the core under conditions of partial degeneracy, the stars then continue to evolve through the asymptotic giant branch (AGB) phase and are known as super-AGB stars. Super-AGB stars have oxygen-neon degenerate cores as opposed to the carbon-oxygen cores of their lower mass counterparts. The final fate of single super-AGB stars depends on the rate of mass loss from the surface: if the core can grow big enough to reach the Chandrasekhar mass then it will explode as an electron capture supernova.
Internet address	https://web.archive.org/web/20170111030144/http://agb-supernovae.weebly.com:80/ https://agb-supernovae.weebly.com/

Keywords

Nuclear reactions, nucleosynthesis, abundances
Stars: abundances
Stars: AGB and post-AGB
Stars: atmospheres
Stars: evolution
Stars: late-type

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Pérez-Mesa, V., Zamora, O., García-Hernández, D. A., Plez, B., Manchado, A., Karakas, A. I., & Lugaro, M. (2017). Exploring circumstellar effects on the Li abundances in massive Galactic AGB stars. In A. Karakas, P. Ventura, F. Dell'Agli, & M. Di Criscienzo (Eds.), Memorie della Societa Astronomica Italiana - Journal of the Italian Astronomical Society: 2017 AGB-Supernovae Mass Transition; Monte Porzio Catone; Italy; 27 March 2017 through 31 March 2017 (3 ed., Vol. 88, pp. 451-454). (Memorie della Società Astronomica Italiana).. http://sait.oat.ts.astro.it/MSAIt880317/index.html

Pérez-Mesa, V. ; Zamora, O. ; García-Hernández, D. A. et al. / Exploring circumstellar effects on the Li abundances in massive Galactic AGB stars. Memorie della Societa Astronomica Italiana - Journal of the Italian Astronomical Society: 2017 AGB-Supernovae Mass Transition; Monte Porzio Catone; Italy; 27 March 2017 through 31 March 2017. editor / A Karakas ; P Ventura ; F Dell'Agli ; M Di Criscienzo. Vol. 88 3. ed. Italy, 2017. pp. 451-454 (Memorie della Società Astronomica Italiana).

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title = "Exploring circumstellar effects on the Li abundances in massive Galactic AGB stars",

abstract = "We have explored the circumstellar effects on the Li abundance determination in a complete sample of O-rich Galactic asymptotic giant branch (AGB) stars, previously studied with hydrostatic models. We use a modified version of the spectral synthesis code Turbospectrum and more realistic extended model atmospheres that consider the presence of a gaseous circumstellar envelope and a radial wind in these massive AGB stars. The Li abundances are determined from the 6708 {\AA} Li I resonance line. The Li pseudo-dynamical abundances obtained are practically identical to those derived with hydrostatic models (a maximum difference of 0.3 dex is found in the only super Li-rich AGB star in our sample). The low Li abundance and therefore negligible Li I column-density in the circumstellar envelope likely explains the small differences between extended and hydrostatic models. Our results confirm the activation of the hot bottom burning (HBB) process in massive Galactic AGB stars.",

keywords = "Nuclear reactions, nucleosynthesis, abundances, Stars: abundances, Stars: AGB and post-AGB, Stars: atmospheres, Stars: evolution, Stars: late-type",

author = "V. P{\'e}rez-Mesa and O. Zamora and Garc{\'i}a-Hern{\'a}ndez, {D. A.} and B. Plez and A. Manchado and Karakas, {A. I.} and M. Lugaro",

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booktitle = "Memorie della Societa Astronomica Italiana - Journal of the Italian Astronomical Society",

edition = "3",

note = "The AGB-Supernovae Mass Transition 2017 ; Conference date: 27-03-2017 Through 31-03-2017",

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Pérez-Mesa, V, Zamora, O, García-Hernández, DA, Plez, B, Manchado, A, Karakas, AI & Lugaro, M 2017, Exploring circumstellar effects on the Li abundances in massive Galactic AGB stars. in A Karakas, P Ventura, F Dell'Agli & M Di Criscienzo (eds), Memorie della Societa Astronomica Italiana - Journal of the Italian Astronomical Society: 2017 AGB-Supernovae Mass Transition; Monte Porzio Catone; Italy; 27 March 2017 through 31 March 2017. 3 edn, vol. 88, Memorie della Società Astronomica Italiana, Italy, pp. 451-454, The AGB-Supernovae Mass Transition 2017, Monte Porzio Catone, Italy, 27/03/17. <http://sait.oat.ts.astro.it/MSAIt880317/index.html>

Exploring circumstellar effects on the Li abundances in massive Galactic AGB stars. / Pérez-Mesa, V.; Zamora, O.; García-Hernández, D. A. et al.
Memorie della Societa Astronomica Italiana - Journal of the Italian Astronomical Society: 2017 AGB-Supernovae Mass Transition; Monte Porzio Catone; Italy; 27 March 2017 through 31 March 2017. ed. / A Karakas; P Ventura; F Dell'Agli; M Di Criscienzo. Vol. 88 3. ed. Italy, 2017. p. 451-454 (Memorie della Società Astronomica Italiana).

Research output: Chapter in Book/Report/Conference proceeding › Conference Paper › Other

TY - GEN

T1 - Exploring circumstellar effects on the Li abundances in massive Galactic AGB stars

AU - Pérez-Mesa, V.

AU - Zamora, O.

AU - García-Hernández, D. A.

AU - Plez, B.

AU - Manchado, A.

AU - Karakas, A. I.

AU - Lugaro, M.

PY - 2017

Y1 - 2017

N2 - We have explored the circumstellar effects on the Li abundance determination in a complete sample of O-rich Galactic asymptotic giant branch (AGB) stars, previously studied with hydrostatic models. We use a modified version of the spectral synthesis code Turbospectrum and more realistic extended model atmospheres that consider the presence of a gaseous circumstellar envelope and a radial wind in these massive AGB stars. The Li abundances are determined from the 6708 Å Li I resonance line. The Li pseudo-dynamical abundances obtained are practically identical to those derived with hydrostatic models (a maximum difference of 0.3 dex is found in the only super Li-rich AGB star in our sample). The low Li abundance and therefore negligible Li I column-density in the circumstellar envelope likely explains the small differences between extended and hydrostatic models. Our results confirm the activation of the hot bottom burning (HBB) process in massive Galactic AGB stars.

AB - We have explored the circumstellar effects on the Li abundance determination in a complete sample of O-rich Galactic asymptotic giant branch (AGB) stars, previously studied with hydrostatic models. We use a modified version of the spectral synthesis code Turbospectrum and more realistic extended model atmospheres that consider the presence of a gaseous circumstellar envelope and a radial wind in these massive AGB stars. The Li abundances are determined from the 6708 Å Li I resonance line. The Li pseudo-dynamical abundances obtained are practically identical to those derived with hydrostatic models (a maximum difference of 0.3 dex is found in the only super Li-rich AGB star in our sample). The low Li abundance and therefore negligible Li I column-density in the circumstellar envelope likely explains the small differences between extended and hydrostatic models. Our results confirm the activation of the hot bottom burning (HBB) process in massive Galactic AGB stars.

KW - Nuclear reactions, nucleosynthesis, abundances

KW - Stars: abundances

KW - Stars: AGB and post-AGB

KW - Stars: atmospheres

KW - Stars: evolution

KW - Stars: late-type

UR - http://www.scopus.com/inward/record.url?scp=85064395903&partnerID=8YFLogxK

M3 - Conference Paper

AN - SCOPUS:85064395903

VL - 88

T3 - Memorie della Società Astronomica Italiana

SP - 451

EP - 454

BT - Memorie della Societa Astronomica Italiana - Journal of the Italian Astronomical Society

A2 - Karakas, A

A2 - Ventura, P

A2 - Dell'Agli, F

A2 - Di Criscienzo, M

CY - Italy

T2 - The AGB-Supernovae Mass Transition 2017

Y2 - 27 March 2017 through 31 March 2017

ER -

Pérez-Mesa V, Zamora O, García-Hernández DA, Plez B, Manchado A, Karakas AI et al. Exploring circumstellar effects on the Li abundances in massive Galactic AGB stars. In Karakas A, Ventura P, Dell'Agli F, Di Criscienzo M, editors, Memorie della Societa Astronomica Italiana - Journal of the Italian Astronomical Society: 2017 AGB-Supernovae Mass Transition; Monte Porzio Catone; Italy; 27 March 2017 through 31 March 2017. 3 ed. Vol. 88. Italy. 2017. p. 451-454. (Memorie della Società Astronomica Italiana).

Exploring circumstellar effects on the Li abundances in massive Galactic AGB stars

Abstract

Publication series

Conference

Keywords

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Exploring circumstellar effects on the lithium and calcium abundances in massive Galactic O-rich AGB stars

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