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Using magnetic activity and Galactic dynamics to constrain the ages of M dwarfs

Published online by Cambridge University Press:  01 October 2008

Andrew A. West ,
Suzanne L. Hawley ,
John J. Bochanski ,
Kevin R. Covey  and
Adam J. Burgasser
Andrew A. West
Affiliation:
MIT Kavli Institute for Astrophysics and Space Research, 77 Massachusetts Ave, Cambridge, MA 02139-4307 email: [email protected], [email protected], [email protected]
Suzanne L. Hawley
Affiliation:
Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 email: [email protected]
John J. Bochanski
Affiliation:
MIT Kavli Institute for Astrophysics and Space Research, 77 Massachusetts Ave, Cambridge, MA 02139-4307 email: [email protected], [email protected], [email protected]
Kevin R. Covey
Affiliation:
Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge MA 02138 email: [email protected]
Adam J. Burgasser
Affiliation:
MIT Kavli Institute for Astrophysics and Space Research, 77 Massachusetts Ave, Cambridge, MA 02139-4307 email: [email protected], [email protected], [email protected]
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Abstract

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We present a study of the dynamics and magnetic activity of M dwarfs using the largest spectroscopic sample of low-mass stars ever assembled. The age at which strong surface magnetic activity (as traced by Hα) ceases in M dwarfs has been inferred to have a strong dependence on mass (spectral type, surface temperature) and explains previous results showing a large increase in the fraction of active stars at later spectral types. Using spectral observations of more than 40000 M dwarfs from the Sloan Digital Sky Survey, we show that the fraction of active stars decreases as a function of vertical distance from the Galactic plane (a statistical proxy for age), and that the magnitude of this decrease changes significantly for different M spectral types. Adopting a simple dynamical model for thin disk vertical heating, we assign an age for the activity decline at each spectral type, and thus determine the activity lifetimes for M dwarfs. In addition, we derive a statistical age-activity relation for each spectral type using the dynamical model, the vertical distance from the Plane and the Hα emission line luminosity of each star (the latter of which also decreases with vertical height above the Galactic plane).

Keywords

stars: activitystars: kinematicsstars: late-typestars: low-massbrown dwarfs
Type
Contributed Papers
Information
Proceedings of the International Astronomical Union , Volume 4 , Symposium S258: The Ages of Stars , October 2008 , pp. 327 - 336
Copyright
Copyright © International Astronomical Union 2009

References

Barry, D. C. 1988, ApJ, 334, 436CrossRefGoogle Scholar
Binney, J., Dehnen, W., & Bertelli, G. 2000, MNRAS, 318, 658CrossRefGoogle Scholar
Bochanski, J. J., Munn, J. A., Hawley, S. L., West, A. A., Covey, K. R., & Schneider, D. P. 2007a, AJ, 134, 2418CrossRefGoogle Scholar
Bochanski, J. J., West, A. A., Hawley, S. L., & Covey, K. R. 2007b, AJ, 133, 531CrossRefGoogle Scholar
Browning, M. K. 2008, ApJ, 676, 1262CrossRefGoogle Scholar
Chabrier, G. & Baraffe, I. 1997, A&A, 327, 1039Google Scholar
Covey, K. R. et al. , 2007, AJ, 134, 2398CrossRefGoogle Scholar
Delfosse, X., Forveille, T., Perrier, C., & Mayor, M. 1998, A&A, 331, 581Google Scholar
Dobler, W., Stix, M., & Brandenburg, A. 2006, ApJ, 638, 336CrossRefGoogle Scholar
Eggen, O. J. 1990, PASP, 102, 166CrossRefGoogle Scholar
Fleming, T. A., Schmitt, J. H. M. M., & Giampapa, M. S. 1995, ApJ, 450, 401CrossRefGoogle Scholar
Fuchs, B., Dettbarn, C., Jahreiß, H., & Wielen, R. 2001, in ASP Conf. Ser. 228: Dynamics of Star Clusters and the Milky Way, ed. Deiters, S., Fuchs, B., Just, A., Spurzem, R., & Wielen, R., 235Google Scholar
Giampapa, M. S. & Liebert, J. 1986, ApJ, 305, 784Google Scholar
Gizis, J. E., Monet, D. G., Reid, I. N., Kirkpatrick, J. D., Liebert, J., & Williams, R. J. 2000, AJ, 120, 1085Google Scholar
Gizis, J. E., Reid, I. N., & Hawley, S. L. 2002, AJ, 123, 3356Google Scholar
Gray, D. F. 1992, Science, 257, 1978Google Scholar
Hänninen, J. & Flynn, C. 2002, MNRAS, 337, 731CrossRefGoogle Scholar
Hawley, S. L., Covey, K. R. et al. , 2002, AJ, 123, 3409Google Scholar
Hawley, S. L., Gizis, J. E., & Reid, I. N. 1996, AJ, 112, 2799CrossRefGoogle Scholar
Hawley, S. L., Reid, I. N., & Tourtellot, J. G. 2000, in Very Low-mass Stars and Brown Dwarfs, Edited by R. Rebolo and M. R. Zapatero-Osorio. Published by the Cambridge University Press, UK, 2000., p.109, ed. Rebolo, R. & Zapatero-Osorio, M. R., 109–+Google Scholar
Hawley, S. L., Tourtellot, J. G., & Reid, I. N. 1999, AJ, 117, 1341CrossRefGoogle Scholar
Kiraga, M. & Stepien, K. 2007, Acta Astronomica, 57, 149Google Scholar
Mamajek, E. E. & Hillenbrand, L. A. 2008, ApJ, 687, 1264CrossRefGoogle Scholar
Mohanty, S. & Basri, G. 2003, ApJ, 583, 451CrossRefGoogle Scholar
Munn, J. A., Monet, D. G., Levine, S. E., Canzian, B., Pier, J. R., Harris, H. C., Lupton, R. H., Ivezić, Ž., Hindsley, R. B., Hennessy, G. S., Schneider, D. P., & Brinkmann, J. 2004, AJ, 127, 3034Google Scholar
Nordström, B., Mayor, M., Andersen, J., Holmberg, J., Pont, F., Jørgensen, B. R., Olsen, E. H., Udry, S., & Mowlavi, N. 2004, A&A, 418, 989Google Scholar
Ossendrijver, M. 2003, A&A Rev., 11, 287Google Scholar
Parker, E. N. 1993, ApJ, 408, 707Google Scholar
Pizzolato, N., Maggio, A., Micela, G., Sciortino, S., & Ventura, P. 2003, A&A, 397, 147Google Scholar
Press, W. H., Teukolsky, S. A., Vetterling, W. T., & Flannery, B. P. 1992, Numerical recipes in C. The art of scientific computing (Cambridge: University Press, –-c1992, 2nd ed.)Google Scholar
Reid, N. & Hawley, S. L., eds. 2005, New light on dark stars: red dwarfs, low mass stars, brown dwarfs, ed. N. Reid & S. L. HawleyGoogle Scholar
Reiners, A. & Basri, G. 2007, ApJ, 656, 1121CrossRefGoogle Scholar
Siebert, A., Bienaymé, O., & Soubiran, C. 2003, A&A, 399, 531Google Scholar
Silvestri, N. M. et al. , 2006, AJ, 131, 1674Google Scholar
Skumanich, A. 1972, ApJ, 171, 565Google Scholar
Soderblom, D. R., Duncan, D. K., & Johnson, D. R. H. 1991, ApJ, 375, 722Google Scholar
Stauffer, J. R., Liebert, J., Giampapa, M., Macintosh, B., Reid, N., & Hamilton, D. 1994, AJ, 108, 160Google Scholar
Thompson, M. J., Christensen-Dalsgaard, J., Miesch, M. S., & Toomre, J. 2003, ARAA, 41, 599CrossRefGoogle Scholar
West, A. A. & Basri, G. 2009, ApJ, submittedGoogle Scholar
West, A. A., Bochanski, J. J., Hawley, S. L., Cruz, K. L., Covey, K. R., Silvestri, N. M., Reid, I. N., & Liebert, J. 2006, AJ, 132, 2507CrossRefGoogle Scholar
West, A. A., Hawley, S. L., Bochanski, J. J., Covey, K. R., Reid, I. N., Dhital, S., Hilton, E. J., & Masuda, M. 2008, AJ, 135, 785Google Scholar
West, A. A. et al. , 2004, AJ, 128, 426Google Scholar
Wielen, R. 1977, A&A, 60, 263Google Scholar
Wilson, O. & Woolley, R. 1970, MNRAS, 148, 463Google Scholar
York, D. G. et al. , 2000, AJ, 120, 1579Google Scholar