Mg and TiO spectral features at the near-IR: spectrophotometric index definitions and empirical calibrations

Thumbnail Image
Full text at PDC
Publication Date
Advisors (or tutors)
Journal Title
Journal ISSN
Volume Title
Google Scholar
Research Projects
Organizational Units
Journal Issue
Using the near-infrared spectral stellar library of Cenarro et al., the behaviour of the Mg i line at 8807 A and nearby TiO bands is analyzed in terms of the effective temperature, surface gravity and metallicity of the library stars. New spectroscopic indices for both spectral features - namely MgI and sTiO - are defined, and their sensitivities to different signal-to-noise ratios, spectral resolutions, flux calibrations and sky emission-line residuals are characterized. The two new indices exhibit interesting properties. In particular, MgI is a good indicator of the Mg abundance, whereas sTiO is a powerful dwarf-to-giant discriminator for cold spectral types. Empirical fitting polynomials that reproduce the strength of the new indices as a function of the stellar atmospheric parameters are computed, and a fortran routine with the fitting function predictions is made available. A thorough study of several error sources, non-solar [Mg/Fe] ratios and their influence on the fitting function residuals is also presented. From this analysis, an [Mg/Fe] underabundance of similar to -0.04 is derived for the Galactic open cluster M67.
This article has been accepted for publication in Monthly notices of the Royal Astronomical Society. © 2009 The Authors. Journal compilation. © 2009 RAS. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved. We acknowledge an anonymous referee for his/her very useful comments. AJC is a Juan de la Cierva Fellow of the Spanish Ministry of Science and Innovation. This work has been funded by the Spanish Ministry of Science and Innovation through grants AYA2007-67752-C03-01 and AYA2006-15698-C02-02.
Borkova T. V., Marsakov V. A., 2005, Astron. Rep., 49, 405 Bruzual G., Charlot S., 2003, MNRAS, 344, 1000 Cardiel N., 2007, in Figueras F., Girart J. M., Hernanz M., Jordi C., eds, Highlights of Spanish Astrophysics IV, Proceedings of the 7th Scientific Meeting of the Spanish Astronomical Society. CDROM. Springer, Berlin Cardiel N., Gorgas J., Cenarro J., González J. J., 1998, A&AS, 127, 597 Carter D., Visvanathan N., Pickles A. J., 1986, ApJ, 311, 637 (CVP) Cenarro A. J., Cardiel N., Gorgas J., Peletier R. F., Vazdekis A., Prada F., 2001a, MNRAS, 326, 959 (CEN01a) Cenarro A. J., Gorgas J., Cardiel N., Vazdekis A., Prada F., 2001b, yCat, 832, 60959 Cenarro A. J., Gorgas J., Cardiel N., Pedraz S., Peletier R. F., Vazdekis A., 2001b, MNRAS, 326, 981 (CEN01b) Cenarro A. J., Gorgas J., Cardiel N., Vazdekis A., Peletier R. F., 2002, MNRAS, 329, 863 (CEN02) Cenarro A. J., Gorgas J., Vazdekis A., Cardiel N., Peletier R. F., 2003, MNRAS, 339, L12 Cenarro A. J. et al., 2007, MNRAS, 374, 664 Chmielewski Y., 2000, A&A, 353, 666 Cid Fernandes R., Mateus A., Sodré L., Stasinska G., Gomes J. M., 2005, MNRAS, 358, 363 Coelho P., Barbuy B., Meléndez J., Schiavon R. P., Castilho B. V., 2005, A&A, 443, 735 (C05) Cohen J. G., 1980, ApJ, 241, 981 Díaz A. I., Terlevich E., Terlevich R., 1989, MNRAS, 239, 325 (DTT) Dressler A., Lynden-Bell D., Burstein D., Davies R. L., Faber S. M., Terlevich R., Wegner G., 1987, ApJ, 313, 42 Edvardsson B., Andersen J., Gustafsson B., Lambert D. L., Nissen P. E., Tomkin J., 1993, A&A, 275, 101 Fanelli M. N., O’Connell R. W., Burstein D., Wu C.-C., 1992, ApJS, 82, 197 Fitzpatrick E. L., 1999, PASP, 111, 63 Foy R., Proust D., 1981, A&A, 99, 221 Friel E. D., Janes K. A., 1993, A&A, 267, 75 Friel E. D., Janes K. A., Tavarez M., Scott J., Katsanis R., Lotz J., Hong L., Miller N., 2002, AJ, 124, 2693 Gilbert K. M. et al., 2006, ApJ, 652, 1188 Gorgas J., Faber S. M., Burstein D., González J. J., Courteau S., Prosser C., 1993, ApJS, 86, 153 Gorgas J., Cardiel N., Pedraz S., González J. J., 1999, A&AS, 139, 29 Gratton R., 2000, in Pallavicini R., Micela G. and Sciortino S., eds, ASP Conf. Ser. Vol. 198. Stellar Clusters and Associations: Convection, Rotation and Dynamos. Astron. Soc. Pac, San Francisco, p. 225 Gratton R. G., Sneden C., 1987, A&A, 178, 179 Gregg M. D. et al., 2004, A&AS, 36, 1496 Heap S. R., Lindler D. J., 2007, in Vallenari A., Tantalo R., Portinari L., eds, From Stars to Galaxies, ASP Conf. Ser. Vol. 374. Astron. Soc. Pac. San Francisco, p. 409 Ivanov V. D., Rieke M. J., Engelbracht C. W., Alonso Herrero A., Rieke G. H., Luhman K. L., 2004, ApJS, 151, 387 Jones L. A., 1998, PhD thesis, Univ. North Carolina Koleva M., Prugniel P., Ocvirk P., Le Borgne D., Soubiran C., 2008, MNRAS, 385, 1998 Lang K. R., 1991, Astrophysical Data: Planets and Stars. Springer-Verlag, Berlin Le Borgne J.-F. et al., 2003, A&A, 402, 433 Le Borgne D., Rocca-Volmerange B., Prugniel P., Lanc¸on A., Fioc M., Soubiran C., 2004, A&A, 425, 881 Maraston C., 2005, MNRAS, 362, 799 Maraston C., Nieves Colmenávez L., Bender R., Thomas D., 2009, A&A, 493, 425 Mármol Queraltó E., Cardiel N., Cenarro A. J., Vazdekis A., Gorgas J., Pedraz S., Peletier R. F., Sánchez Blázquez P., 2008, A&A, 489, 885 Mathis H., Charlot S., Brinchmann J., 2006, MNRAS, 365, 385 Ocvirk P., Pichon C., Lanc¸on A., Thiébaut E., 2006a, MNRAS, 365, 46 Ocvirk P., Pichon C., Lanc¸on A., Thiébaut E., 2006b, MNRAS, 365, 74 Panter B., Heavens A. F., Jiménez R., 2003, MNRAS, 343, 1145 Panter B., Jiménez R., Heavens A. F., Charlot S., 2007, MNRAS, 378, 1550 Pilachowski C. A., Sneden C., Kraft R. P., 1996, AJ, 111, 1689 Prugniel P., Soubiran C., 2001, A&A, 369, 1048 Prugniel P., Soubiran C., 2004, preprint (arXiv:astro-ph/0409214) Prugniel P., Soubiran C., Koleva M., Le Borgne D., 2007, preprint (arXiv:astro-ph/0703658) Ranade A., Gupta R., Ashok N. M., Singh H. P., 2004, Bull. Astron. Soc. India, 32, 311 Ranade A. C., Singh H. P., Gupta R., Ashok N. M., 2007a, Bull. Astron. Soc. India, 35, 87 Ranade A. C., Ashok N. M., Singh H. P., Gupta R., 2007b, Bull. Astron. Soc. India, 35, 359 Rousselot P., Lidman C., Cuby J.-G., Moreels G., Monnet G., 2000, A&A, 354, 1134 Sánchez Blázquez P. et al., 2006, MNRAS, 371, 703 Schiavon R. P., 2007, ApJS, 171, 146 Schiavon R. P., Caldwell N., Rose J. A., 2004, AJ, 127, 1513 Shetrone M. D., Sandquist E. L., 2000, AJ, 120, 1913 Soubiran C., Katz D., Cayrel R., 1998, A&AS, 133, 221 Stevenson C. C., 1994, MNRAS, 267, 904 Tautvaisiene G., Edvardsson B., Tuominen I., Ilyin I., 2000, A&A, 360, 499 Thévenin F., 1998, yCat, 3193, 0 Thomas D., Maraston C., Bender R., 2003, MNRAS, 339, 897 Valdés F., Gupta R., Rose J. A., Singh H. P., Bell D. J., 2004, ApJS, 152, 251 Vazdekis A., 1999, ApJ, 513, 224 Vazdekis A., Casuso E., Peletier R. F., Beckman J. E., 1996, ApJS, 106, 307 Vazdekis A., Cenarro A. J., Gorgas J., Cardiel N., Peletier R. F., 2003, MNRAS, 340, 1317 (VAZ03) Worthey G., 1994, ApJS, 95, 107 Worthey G., Ottaviani D. L., 1997, ApJS, 111, 377 Worthey G., Faber S. M., Gonzalez J. J., 1992, ApJ, 398, 69 Worthey G., Faber S. M., Gonzalez J. J., Burstein D., 1994, ApJS, 94, 687