Skip to main content
Log in

On the dynamical evolution of the brown dwarf populationin open clusters

  • Published:
Astrophysics and Space Science Aims and scope Submit manuscript

Abstract

It is by now well established that open clusters contain a considerable fraction of brown dwarfs (BDs). This paper investigates the dynamical evolution of this substellar population by using simulations with Aarseth's (1994) NBODY5 code. A noticeable preferential escape of BDs is found, which may influence the determination of the IMF of substellar objects in dynamically evolved open clusters. This small dynamical-in-origin depletion may not explain, however, the scarcity of BDs observed in some evolved clusters, as the Hyades. On the other hand, BD cooling processes are able to reduce our ability to detect BDs in old clusters in a very significant way. Our results confirm that the probability of observing BDs in open clusters is almost the same over the whole cluster area because they are distributed quite uniformly even at late stages of the evolution of the cluster. This is expected to be a general feature as observed for low-mass stars in well studied open clusters (Pleiades, Praesepe). Our present calculations show that clusters as old as the Pleiades may have lost about 10% of their initial BD population but the number ratio of BDs to normal (not substellar) stars must remain almost unchanged. However, the long-term behavior of the relative percentage of BDs depends strongly on the initial mass function (IMF) assumed in the calculations. Clusters with a Salpeterian IMF evolve to reach relative percentages of BDs as low as 40% for a starting value around 70%. Our results suggest that BDs in clusters escape preferentially by evaporation.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  • Aarseth S.J.: 1985, in: J.U. Brackbill and B.I. Cohen (eds.), Multiple Time Scales, Academic Press, New York, pp. 377.

    Google Scholar 

  • Aarseth S.J.: 1994, in: G. Contopoulos, N.K. Spyrou and L. Vlahos (eds.), Galactic Dynamics and N-body Simulations, Springer Verlag, Berlin, pp. 277.

    Google Scholar 

  • Allard, F., Hauschildt, P.H., Baraffe, I. and Chabrier, G.: 1996, Astrophys.J. 465, L123.

    Article  ADS  Google Scholar 

  • Allard, F., Hauschildt, P.H., Alexander, D.R. and Starrfield, S.: 1997, Annu.Rev.Astron.Astrophys. 35, 137.

    Article  ADS  Google Scholar 

  • Basri, G.: 1998, in: G. Micela, R. Pallavicini and G. Sciortino (eds.), Cool stars in Clusters and Associations, Mem. S.A. It.Vol. 68, No. 4, in press.

  • Basri, G. and Martín, E.L.: 1998a, in: R. Rebolo, E. Martín and M.R. Zapatero Osorio (eds.), Brown Dwarfs and Extrasolar Planets, ASP Conference Series 134, 284.

  • Basri, G. and Martín, E.L.: 1998b, Astrophys.J., submitted.

  • Basri, G., Marcy, G. and Graham, J.R.: 1996, Astrophys.J. 458, 600.

    Article  ADS  Google Scholar 

  • Becklin, E.E. and Zuckerman, B.: 1988, Nature 336, 656.

    Article  ADS  Google Scholar 

  • Bessell, M.S. and Stringfellow, G.S.: 1993, Annu.Rev.Astron.Astrophys. 31, 433.

    Article  ADS  Google Scholar 

  • Bildsten, L., Brown, E.F., Matzner, C.D. and Ushomirsky, G.: 1997, Astrophys.J. 482, 442.

    Article  ADS  Google Scholar 

  • Bouvier, J., Stauffer, J.R., Martín, E.L., Barrado y Navascues, D., Wallace, B. and Bejar, V.J.S.: 1998, Astron.Astrophys. 336, 490.

    ADS  Google Scholar 

  • Briceño, C., Hartmann, L., Stauffer, J.R. and Martín, E.: 1998, Astron.J. 115, 2074.

    Article  ADS  Google Scholar 

  • Comeron, F. and Claes P.: 1998, in: R. Rebolo, E. Martín and M.R. Zapatero Osorio (eds.), Brown Dwarfs and Extrasolar Planets, ASP Conference Series 134, 43.

  • Comeron, F., Rieke, G.H., Claes, P., Torra, J. and Laureijs R.J.: 1998, Astron.Astrophys. 335, 522.

    ADS  Google Scholar 

  • Cossburn, M.R., Hodgkin, S.T., Jameson, R.F. and Pinfield, D.J.: 1997, Mon.Not.R.Astron.Soc. 288, 23.

    ADS  Google Scholar 

  • Cossburn, M.R., Hodgkin, S.T., Jameson, R.F. and Pinfield D.J.: 1998, in: R. Rebolo, E. Martín and M.R. Zapatero Osorio (eds.), Brown Dwarfs and Extrasolar Planets, ASP Conference Series 134, 333.

  • Eggleton, P.P., Fitchett, M.J. and Tout, C.A.: 1989, Astrophys.J. 347, 998.

    Article  ADS  Google Scholar 

  • Festin, L.: 1997, Astron.Astrophys. 322, 455.

    ADS  Google Scholar 

  • Festin, L.: 1998, Astron.Astrophys. 333, 497.

    ADS  Google Scholar 

  • de la Fuente Marcos, R.: 1996, Astron.Astrophys. 308, 141.

    ADS  Google Scholar 

  • Gizis, J.E., Reid, I.N. and Monet, D.G.: 1999, Astron.J., in press.

  • Guinan, E.F., Bradstreet, D.H., Ribas, I., Wolf, M. and McCook, G.P.: 1998, Bull.Am.Astron.Soc. 192, 12.13.

    ADS  Google Scholar 

  • Hawkins, M.R.S., Ducourant, C., Jones, H.R.A. and Rapaport, M.: 1998, Mon.Not.R.Astron.Soc. 294, 505.

    Article  ADS  Google Scholar 

  • Heggie, D.C.: 1980, in: D. Hanes and B. Madore (eds.), Globular Clusters, Cambridge University Press, Cambridge, pp. 281.

    Google Scholar 

  • Hodgkin, S. and Jameson, R.F.: 1997, Cont.Phys. 38, 395.

    Article  ADS  Google Scholar 

  • von Hoerner, S.: 1976, Astron.Astrophys. 46, 293.

    ADS  Google Scholar 

  • Jameson, R.F.: 1995, in E.D.: Tinney (ed.), The Bottom of the Main Sequence and Beyond, ESO Workshop, pp. 183.

  • Jeans, J.H.: 1929, Astronomy and Cosmogony, 2nd. ed., Cambridge University Press; also Dover, New York, 1961.

    Google Scholar 

  • Kirkpatrick, J.D., Cutri, R.M., Nelson, B., Beichman, C.A., Reid, I.N., Liebert, J., Dahn, C.C., Monet, D.G. and Skrutskie, M.F.: 1998, Bull.Am.Astron.Soc. 192, 55.04.

    ADS  Google Scholar 

  • Kroupa, P.: 1995a, Mon.Not.R.Astron.Soc. 277, 1491.

    ADS  Google Scholar 

  • Kroupa, P.: 1995b, Mon.Not.R.Astron.Soc. 277, 1522.

    ADS  Google Scholar 

  • Kroupa, P.: 1998, in: R. Rebolo, E. Martín and M.R. Zapatero Osorio (eds.), Brown Dwarfs and Extrasolar Planets, ASP Conference Series 134, 483.

  • Kroupa, P., Tout, C.A. and Gilmore, G.: 1991, Mon.Not.R.Astron.Soc. 251, 293.

    ADS  Google Scholar 

  • Kroupa, P., Tout, C.A. and Gilmore, G.: 1993, Mon.Not.R.Astron.Soc. 262, 545.

    ADS  Google Scholar 

  • Kulkarni, S.R.: 1997, Science 276, 1350.

    Article  ADS  Google Scholar 

  • van Leeuwen, F.: 1983, Ph.D.dissertation, Sterrenwacht Leiden, The Netherlands.

  • Luhman, K.L. and Rieke, G.H.: 1998, Astrophys.J. 497, 354.

    Article  ADS  Google Scholar 

  • Macintosh, B., Zuckerman, B., Becklin, E.E. and McLean, I.S.: 1996, Bull.Am.Astron.Soc. 189, 120.05.

    ADS  Google Scholar 

  • MagazzÚ, A., Rebolo, R., Zapatero Osorio, M.R., Martín, E.L. and Hodgkin, S.T.: 1998, Astrophys.J. 497, L47.

    Article  ADS  Google Scholar 

  • Martín, E.L., Rebolo, R. and Zapatero Osorio, M.R.: 1996, Astrophys.J. 469, 706.

    Article  ADS  Google Scholar 

  • Mathieu, R.D.: 1985, IAU Symp. 113, 427.

    ADS  Google Scholar 

  • Nakajima, T., Oppenheimer, B.R., Kulkarni, S.R., Golimowski, D.A., Matthews, K. and Durrance, S.T.: 1995, Nature 378, 463.

    Article  ADS  Google Scholar 

  • Oppenheimer, B.R., Kulkarni S.R. and Stauffer J.R.: 1999, in: V. Mannings, A. Boss and S. Russell (eds.), Protostars and Planets IV, Tucson, University of Arizona Press, in press.

    Google Scholar 

  • Oppenheimer, B.R., Basri, G., Nakajima, T. and Kulkarni, S.R.: 1997, Astron.J. 113, 296.

    Article  ADS  Google Scholar 

  • Pavlovsky, C.M. and Patten, B.M.: 1997, Bull.Am.Astron.Soc. 191, 80.15.

    ADS  Google Scholar 

  • Pinfield, D.J., Hodgkin, S.T., Jameson, R.F., Cossburn, M.R. and Von Hippel, T.: 1997, Mon.Not.R.Astron.Soc. 287, 180.

    ADS  Google Scholar 

  • Pound, M.W. and Blitz, L.: 1993, Astrophys.J. 418, 328.

    Article  ADS  Google Scholar 

  • Pound, M.W. and Blitz, L.: 1995, Astrophys.J. 444, 270.

    Article  ADS  Google Scholar 

  • Raboud, D. and Mermilliod, J.-C.: 1998a, Astron.Astrophys. 329, 101.

    ADS  Google Scholar 

  • Raboud, D. and Mermilliod, J.-C.: 1998b, Astron.Astrophys. 333, 897.

    ADS  Google Scholar 

  • Rebolo, R., Martín, E.L. and MagazzÚ, A.: 1992, Astrophys. J. 389, L83.

    Article  ADS  Google Scholar 

  • Rebolo, R., Zapatero Osorio, M.R. and Martín, E.L.: 1995, Nature 377, 129.

    Article  ADS  Google Scholar 

  • Rebolo, R., Martín, E.L., Basri, G., Marcy, G.W. and Zapatero Osorio, M.R.: 1996, Astrophys.J. 469, L53.

    Article  ADS  Google Scholar 

  • Reid, I.N. and Gizis, J.E.: 1997, Astron.J. 114, 1992.

    Article  ADS  Google Scholar 

  • Reid, I.N., Kirkpatrick, D., Beichman, C.A., Liebert, J., Burrows, A. and Skrutskie, M.: 1998, Bull.Am.Astron.Soc. 192, 55.17.

    ADS  Google Scholar 

  • Reid, I.N., Kirkpatrick, D., Liebert, J., Burrows, A., Gizis, J.E., Burgasser, A., Dahn, C.C., Monet, D., Cutri, R., Beichman, C.A. and Skrutskie, M.: 1999, Astrophys.J., in press.

  • Ruiz, M.T., Leggett, S.K. and Allard, F.: 1997, Astrophys.J. 491, L107.

    Article  ADS  Google Scholar 

  • Salpeter, E.E.: 1955, Astrophys.J. 121, 161.

    Article  ADS  Google Scholar 

  • Sartoretti, P., Brown, R.A., Latham, D.W. and Torres, G.: 1998, Astron.Astrophys. 334, 592.

    ADS  Google Scholar 

  • Spitzer, L. Jr.: 1987, Dynamical Evolution of Globular Clusters, Princeton University Press, pp. 40.

  • Stauffer, J.R., Schultz, G. and Kirkpatrick, J.D.: 1998, Astrophys.J. 499, L199.

    Article  ADS  Google Scholar 

  • Terlevich, E.: 1987, Mon.Not.R.Astron.Soc. 224, 193.

    ADS  Google Scholar 

  • Tinney, C.G.: 1998, Mon.Not.R.Astron.Soc. 296, L42.

    Article  ADS  Google Scholar 

  • Tinney, C.G., Delfosse, X. and Forveille, T.: 1997, Astrophys.J. 490, L95.

    Article  ADS  Google Scholar 

  • Tinney, C.G., Delfosse, X., Forveille, T. and Allard, F.: 1998, Astron.Astrophys., submitted.

  • White, R.J., Ghez, A.M., Schultz, G. and Reid, I.N.: 1998, Bull.Am.Astron.Soc. 192, 10.01.

    ADS  Google Scholar 

  • Wilking, B.A., Greene, T.P. and Meyer, M.R.: 1997, Bull.Am.Astron.Soc. 191, 70.09.

    ADS  Google Scholar 

  • Williams, D.M., Comerón, F., Rieke, G.H. and Rieke, M.J.: 1995, Astrophys.J. 454, 144.

    Article  ADS  Google Scholar 

  • Williams, D.M., Boyle, R.P., Morgan, W.T., Rieke, G.H., Stauffer, J.R. and Rieke, M.J.: 1996, Astrophys.J. 464, 238.

    Article  ADS  Google Scholar 

  • Zapatero Osorio, M.R., Rebolo, R., Martín, E.L. and García López, R.J.: 1996, Astron.Astrophys. 305, 519.

    ADS  Google Scholar 

  • Zapatero Osorio, M.R., Rebolo, R. and Martín, E.L.: 1997a, Astron.Astrophys. 317, 164.

    ADS  Google Scholar 

  • Zapatero Osorio, M.R., Martín, E.L. and Rebolo, R.: 1997b, Astron.Astrophys. 323, 105.

    ADS  Google Scholar 

  • Zapatero Osorio, M.R., Rebolo, R., Martín, E.L., Hodgkin, S.T., Jameson, R.F., Cossburn, M.R., Magazzù, A., Basri, G. and Steele, I.A.: 1998, in: R. Rebolo, E. Martín and M.R. Zapatero Osorio (eds.), Brown Dwarfs and Extrasolar Planets, ASP Conference Series 134, 51.

Download references

Author information

Authors and Affiliations

Authors

Rights and permissions

Reprints and permissions

About this article

Cite this article

de la Fuente Marcos, R., de la Fuente Marcos, C. On the dynamical evolution of the brown dwarf populationin open clusters. Astrophysics and Space Science 271, 127–144 (2000). https://doi.org/10.1023/A:1002478119185

Download citation

  • Issue Date:

  • DOI: https://doi.org/10.1023/A:1002478119185

Keywords

Navigation