CaltechAUTHORS
  A Caltech Library Service

Magnesium Isotopes in Metal-poor Dwarfs: The Rise of AGB Stars and the Formation Timescale of the Galactic Halo

Meléndez, Jorge and Cohen, Judith G. (2007) Magnesium Isotopes in Metal-poor Dwarfs: The Rise of AGB Stars and the Formation Timescale of the Galactic Halo. Astrophysical Journal Letters, 659 (1). L25-L28. ISSN 2041-8205. doi:10.1086/516735. https://resolver.caltech.edu/CaltechAUTHORS:20100223-132200164

[img]
Preview
PDF - Published Version
See Usage Policy.

89kB
[img] PDF - Accepted Version
See Usage Policy.

184kB

Use this Persistent URL to link to this item: https://resolver.caltech.edu/CaltechAUTHORS:20100223-132200164

Abstract

We have determined magnesium isotopic ratios (^(25, 26)Mg/Mg) in metal-poor (-2.6 ≤ [Fe/H] ≤ -1.3) halo dwarfs employing high signal-to-noise ratio (S/N = 90-280), high spectral resolution (R = 10^5) Keck High Resolution Echelle Spectrometer (HIRES) spectra. Unlike previous claims of an important contribution from intermediate-mass asymptotic giant branch (AGB) stars at low metallicities, we find that the rise of the AGB contribution in the Galactic halo did not occur until intermediate metallicities ([Fe/H] ≳ -1.5).


Item Type:Article
Related URLs:
URLURL TypeDescription
https://doi.org/10.1086/516735 DOIArticle
https://arxiv.org/abs/astro-ph/0702655arXivDiscussion Paper
ORCID:
AuthorORCID
Meléndez, Jorge0000-0002-4933-2239
Cohen, Judith G.0000-0002-8039-4673
Additional Information:© 2007 The American Astronomical Society. Received 2007 January 24; accepted 2007 February 26; published 2007 March 9. J. M. thanks C. Chiappini for useful discussions and D. Yong for providing data to check our MgH line list as well as for useful discussions on Mg isotopic ratios. J. G. C. is grateful for partial support from NSF grant AST-0507219. We have made use of data from the SIMBAD database operated at CDS. The authors wish to recognize and acknowledge the very significant cultural role and reverence that the summit of Mauna Kea has always had within the indigenous Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain.
Funders:
Funding AgencyGrant Number
NSFAST-0507219
Subject Keywords:galaxy : halo; stars : abundances; stars : AGB and post-AGB; stars : atmospheres; stars : Population II
Issue or Number:1
DOI:10.1086/516735
Record Number:CaltechAUTHORS:20100223-132200164
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:20100223-132200164
Official Citation:Magnesium Isotopes in Metal-poor Dwarfs: The Rise of AGB Stars and the Formation Timescale of the Galactic Halo Jorge Meléndez and Judith G. Cohen 2007 ApJ 659 L25-L28 doi: 10.1086/516735
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:17566
Collection:CaltechAUTHORS
Deposited By: Tony Diaz
Deposited On:02 Mar 2010 17:46
Last Modified:08 Nov 2021 23:36

Repository Staff Only: item control page