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Classical T Tauri Stars and Substellar Analogs

Classification Based on Empirical Criteria
  • D. Barrado Y Navascués
  • E. L. Martín
  • R. Jayawardhana
  • S. Mohanty
Chapter

Abstract

We propose a spectroscopic criterion based on Hα equivalent width and spectral type to classify classical T Tauri stars and substellar analogs. We argue that accreting objects can be identified from low-resolution optical spectroscopy, when their Hα flux is stronger than the saturation limit at Log {Lum(Hα)/Lum(bol)} = −3.3. Additional criteria, such as the relation between HeI5876 or HeI6678 and Hα, or the ratios between the components of the CaII infrared triplet, are also discussed. We have tested the reliability of these criteria by applying them to several objects with masses in the range 0.11–0.025 M, which belong to nearby star forming regions and the TW Hya association.

Keywords

classical T Tauri brown dwarfs 

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References

  1. Alencar, S.H.P., Basri, G.: 2000, AJ 119, 1881.CrossRefADSGoogle Scholar
  2. Appenzeller, I., Mundt, R.: 1989, A and A Rev. 1, 291.ADSGoogle Scholar
  3. Baraffe, I. Chabrier, G., Allard, F. et al., 1998, A and A 337 403.Google Scholar
  4. Barrado y Navascués, D.,Martin, E.L.: 2003, AJ 126, 2997.CrossRefADSGoogle Scholar
  5. Barrado y Navascués, D., Stauffer, J.R.: 2003, in: E.L. Martin (eds.), Brown Dwarfs, IAU Symposium 211, p. 155.Google Scholar
  6. Barrado y Navascués, D., Mohanty, S., Jayawardhana, R.: 2004, ApJ 604, 284.CrossRefADSGoogle Scholar
  7. Bertout, C.: 1989, Ann. Rev. Astron. Astroph. 27, 351.CrossRefADSGoogle Scholar
  8. Briceíio, C., Hartmann, L., Stauffer, J.R., Martin, E.L.: 1998, AJ 115, 2074.CrossRefADSGoogle Scholar
  9. Fernandez, M.,Comerón, F.: 2001, A and A 380, 264.CrossRefADSGoogle Scholar
  10. Gershberg, R.E., Katsova, M.M., Lovkaya, M.N., Terebizh, A.V.,Shakhovskaya, N.I.: 1999, A and A Suppl. Series 139, 555.CrossRefADSGoogle Scholar
  11. Gizis, J.E., Monet, D.G., Reid, I.N., Kirkpatrick, J.D., Liebert, J., William, R.J.: 2000, AJ 120, 1085.CrossRefADSGoogle Scholar
  12. Gizis, J.E.: 2002, ApJ 575, 484.CrossRefADSGoogle Scholar
  13. Hamann, F., Perssons, S.E.: 1992, ApJ Suppl. Series 82, 247.CrossRefADSGoogle Scholar
  14. Herbig, G.H., Bell, K.R.:1988, Lick Observatory Bulletin,Lick Observatory.Google Scholar
  15. Kenyon, S.J., Hartmann, L.: 1995, ApJ Suppl. Series 101, 117.CrossRefADSGoogle Scholar
  16. Kirkpatrick, D., Reid, I.N., Liebert, J., Gizis, J.E., Burgasser, A.J., Monet, D.G., Dahn, C.C., Nelson, B., Williams, R.J.: 2000, AJ 120, 447.CrossRefADSGoogle Scholar
  17. Leggett, S.K.: 1992, ApJ Suppl. Series 82, 351.CrossRefADSGoogle Scholar
  18. Martin, E.L.: 1997, A and A 321, 492.ADSGoogle Scholar
  19. Meyer, M.R., Calvet, N., Hillenbrand, L.A.: 1997, AJ 114, 288.CrossRefADSGoogle Scholar
  20. Mohanty, S., Basri, G., Shu, F. et al.: 2002, ApJ 571, 469.CrossRefADSGoogle Scholar
  21. Mohanty, S. and Basri, G.: 2003, Api 583, 451.ADSGoogle Scholar
  22. Mohanty, S., Jayawardhana, R., Barrado, y Navascués, D.: 2003, Api Letters 593, 109.CrossRefADSGoogle Scholar
  23. Montes, D., López-Santiago, J., Fernandez-Figueroa, M.J., Gâlvez, M.C.: 2001, A and A 379, 976.CrossRefADSGoogle Scholar
  24. Muzerolle, J., Calvet, N., Bricno C., Hartmann L., Hillenbrand, L.: 2000, Api Letters 535, 47.CrossRefADSGoogle Scholar
  25. Muzerolle, J. et al.: 2003, ApJ 592, 266.CrossRefADSGoogle Scholar
  26. Reid, I.N., kirkpatrick, J.D., Liebert, J., Gizis, J.E., Dahn, C.C., Monet, D.G.: 2002, AJ 124, 519.CrossRefADSGoogle Scholar
  27. Vuong, M.H., Cambrésy, L., Epchtein, N.: 2001, A and A 379, 208.CrossRefADSGoogle Scholar
  28. White, R.J., Basri, G.: 2003, ApJ 582, 2109.Google Scholar
  29. Zapatero-Osorio, M.R., Béjar, V.J.S., Martin, E.L., Barrado y Navascués, D., Rebolo, R.: 2002, Api Letters 569, 99.CrossRefADSGoogle Scholar

Copyright information

© Springer Science+Business Media Dordrecht 2004

Authors and Affiliations

  • D. Barrado Y Navascués
    • 1
  • E. L. Martín
    • 2
  • R. Jayawardhana
    • 3
  • S. Mohanty
    • 4
  1. 1.Laboratorio de Astrofísica Espacial y Física Fundamental (LAEFF-INTA)MadridSpain
  2. 2.Institute for AstronomyUniversity of HawaiiUSA
  3. 3.Department of AstronomyUniversity of MichiganUSA
  4. 4.Harvard-Smithsonian Center for AstrophysicsCambridgeUSA

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