Sign on

SAO/NASA ADS Astronomy Abstract Service

· Find Similar Abstracts (with default settings below)
· Electronic Refereed Journal Article (HTML)
· Full Refereed Journal Article (PDF/Postscript)
· arXiv e-print (arXiv:1112.4567)
· On-line Data
· References in the article
· Citations to the Article (125) (Citation History)
· Refereed Citations to the Article
· SIMBAD Objects (140)
· Also-Read Articles (Reads History)
·
· Translate This Page
Title:
Metallicity and Temperature Indicators in M Dwarf K-band Spectra: Testing New and Updated Calibrations with Observations of 133 Solar Neighborhood M Dwarfs
Authors:
Rojas-Ayala, Bárbara; Covey, Kevin R.; Muirhead, Philip S.; Lloyd, James P.
Affiliation:
AA(Department of Astrophysics, American Museum of Natural History, Central Park West at 79th Street, New York, NY 10024, USA ; Department of Astronomy, Cornell University, 122 Sciences Drive, Ithaca, NY 14853, USA ; Z. Carter Patten '25 Fellow. ; ), AB(Department of Astronomy, Cornell University, 122 Sciences Drive, Ithaca, NY 14853, USA ; Hubble Fellow. ; Visiting Researcher, Department of Astronomy, Boston University, 725 Commonwealth Ave, Boston, MA 02215, USA.), AC(Department of Astronomy, California Institute of Technology, 1200 East California Boulevard, MC 249-17, Pasadena, CA 91125, USA ), AD(Department of Astronomy, Cornell University, 122 Sciences Drive, Ithaca, NY 14853, USA )
Publication:
The Astrophysical Journal, Volume 748, Issue 2, article id. 93, 32 pp. (2012). (ApJ Homepage)
Publication Date:
04/2012
Origin:
IOP
Astronomy Keywords:
stars: abundances, stars: fundamental parameters, stars: late-type
DOI:
10.1088/0004-637X/748/2/93
Bibliographic Code:
2012ApJ...748...93R

Abstract

We present K-band spectra for 133 nearby (d < 33 ps) M dwarfs, including 18 M dwarfs with reliable metallicity estimates (as inferred from an FGK type companion), 11 M dwarf planet hosts, more than 2/3 of the M dwarfs in the northern 8 pc sample, and several M dwarfs from the LSPM catalog. From these spectra, we measure equivalent widths of the Ca and Na lines, and a spectral index quantifying the absorption due to H2O opacity (the H2O-K2 index). Using empirical spectral type standards and synthetic models, we calibrate the H2O-K2 index as an indicator of an M dwarf's spectral type and effective temperature. We also present a revised relationship that estimates the [Fe/H] and [M/H] metallicities of M dwarfs from their Na I, Ca I, and H2O-K2 measurements. Comparisons to model atmosphere provide a qualitative validation of our approach, but also reveal an overall offset between the atomic line strengths predicted by models as compared to actual observations. Our metallicity estimates also reproduce expected correlations with Galactic space motions and Halpha emission line strengths, and return statistically identical metallicities for M dwarfs within a common multiple system. Finally, we find systematic residuals between our H2O-based spectral types and those derived from optical spectral features with previously known sensitivity to stellar metallicity, such as TiO, and identify the CaH1 index as a promising optical index for diagnosing the metallicities of near-solar M dwarfs.
Bibtex entry for this abstract   Preferred format for this abstract (see Preferences)
  New!

Find Similar Abstracts:

Use: Authors
Title
Keywords (in text query field)
Abstract Text
Return: Query Results Return    items starting with number
Query Form
Database: Astronomy
Physics
arXiv e-prints