Hostname: page-component-586b7cd67f-vdxz6 Total loading time: 0 Render date: 2024-12-01T02:47:19.609Z Has data issue: false hasContentIssue false
  • English
  • Français

Gravitational Microlensing, The Distance Scale, And The Ages

Published online by Cambridge University Press:  25 May 2016

Bohdan Paczyński
Bohdan Paczyński*
Affiliation:
Princeton University Observatory, 124 Peyton Hall, Princeton, NJ 08544-1001, USA

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

A high optical depth to gravitational microlensing towards the galactic bulge is consistent with current models of the galactic bar. The low optical depth towards the LMC can probably be accounted for by the ordinary stars in our galaxy and in the LMC itself. No conclusive evidence is available yet for the presence or absence of a large number of brown dwarfs or other non-stellar compact objects which might account for the dark matter. There is little doubt that the amount of mass in objects in the range 10–8 ≤ M/M⊙ ≤ 106 will be determined within the next few years with the continuing and expanding searches.

Billions of photometric measurements generated by the microlensing searches have lead to the discovery of ∼ 105 variable stars. In particular, a number of detached eclipsing binaries were discovered in the galactic bulge, in the LMC, and in the globular cluster Omega Centauri. The follow-up observations of these binaries will allow the determination of accurate distances to all these objects, as well as robust age determination of globular clusters.

Type
Chapter 7: Microlensing In the Galaxy
Information
Symposium - International Astronomical Union , Volume 173: Astrophysical Applications of Gravitational Lensing , 1996 , pp. 199 - 208
Copyright
Copyright © Kluwer 1996 

References

Alard, C., 1995, these proceedings Google Scholar
Alard, C., Mao, S., & Guibert, J., 1995, A&A, 300, L17 Google Scholar
Alcock, C. et al., 1993, Nature, 365, 621 CrossRefGoogle Scholar
Alcock, C. et al., 1995a, Phys. Rev. Letters, 74, 2867 CrossRefGoogle Scholar
Alcock, C. et al., 1995b, AJ, 109, 1653 CrossRefGoogle Scholar
Alcock, C. et al., 1995c, ApJ, 445, 133 CrossRefGoogle Scholar
Alcock, C. et al., 1995d, preprint Google Scholar
Andersen, J., 1991, A&AR, 3, 91 Google Scholar
Aubourg, E. et al., 1993, Nature, 365, 623 CrossRefGoogle Scholar
Aubourg, E. et al., 1995, preprint Google Scholar
Bell, S. A. et al., 1991, MNRAS, 250, 119 CrossRefGoogle Scholar
Bell, S. A. et al., 1993, MNRAS, 265, 1047 CrossRefGoogle Scholar
Chaboyer, B. et al., 1995, ApJ, 444, L9 CrossRefGoogle Scholar
Colley, W. N., 1995, AJ, 109, 440 CrossRefGoogle Scholar
Cook, K. H. et al., 1995, preprint Google Scholar
Crotts, A. P. S., 1992, ApJ, 399, L43 CrossRefGoogle Scholar
DiStefano, R. & Esin, A. A., 1995, ApJ, 448, L1 Google Scholar
Dommanget, J., & Lampens, P., 1992, in PASP Conf. Ser. Vol. 32, eds. McAlister, H.A. & Hartkopf, W.I., p. 435 Google Scholar
Dreshel, H. et al., 1989, A&A, 221, 49 Google Scholar
Gatewood, G., 1995, ApJ, 445, 712 CrossRefGoogle Scholar
Gatewood, G. et al., 1995, AJ, 109, 434 CrossRefGoogle Scholar
Goecking, K.-D. et al., 1994, A&A, 289, 827 Google Scholar
Gould, A., 1992, ApJ, 392, 442 CrossRefGoogle Scholar
Gould, A., 1995, these proceedings CrossRefGoogle Scholar
Griest, K. et al., 1991, ApJ, 372, L79 CrossRefGoogle Scholar
Grison, P. et al., 1995, A&AS, 109, 447 Google Scholar
Hilditch, R.W., 1995, in to appear in “Binaries in Clusters”, ASP Conf. Ser., eds. Milone, G. and Mermilliod, J.-C. Google Scholar
Kaluzny, J. et al., 1995a, A&A, in press Google Scholar
Kaluzny, J. et al., 1995b, to appear in “Binaries in Clusters”, ASP Conf. Ser., eds. Milone, G. and Mermilliod, J.-C. Google Scholar
Kiraga, M. & Paczyński, B., 1994, ApJ, 430, 101 CrossRefGoogle Scholar
Mao, S. & Paczyński, B., 1991, ApJ, 374, L37 CrossRefGoogle Scholar
Metcalfe, T. S., Mathieu, R. D., Latham, D. W. & Torres, G., 1995, preprint Google Scholar
Monet, D. G. et al., 1992, AJ, 103, 638 CrossRefGoogle Scholar
Paczyński, B., 1984, ApJ, 284, 670 CrossRefGoogle Scholar
Paczyński, B., 1986, ApJ, 304, 1 CrossRefGoogle Scholar
Paczyński, B., 1991, ApJ, 371, L63 CrossRefGoogle Scholar
Paczyński, B. et al., 1994, ApJ, 435, L113 CrossRefGoogle Scholar
Paczyński, B., 1995a, Acta Astron., 45, 345 Google Scholar
Paczyński, B., 1995b, Acta Astron., 45, 349 Google Scholar
Pan, X. et al., 1990, ApJ, 356, 641 CrossRefGoogle Scholar
Pan, X. et al., 1992, ApJ, 384, 633 CrossRefGoogle Scholar
Ramseyer, T.F., 1994, ApJ, 425, 243 CrossRefGoogle Scholar
Pratt, M. R. et al., 1995, these proceedings Google Scholar
Sahu, K., 1994, Nature, 370, 275 CrossRefGoogle Scholar
Shi, X., 1995, ApJ, 446, 637 CrossRefGoogle Scholar
Stubbs, C. et al., 1995, these proceedings Google Scholar
Udalski, A. et al., 1993, Acta Astron., 43, 289 Google Scholar
Udalski, A. et al., 1994a, ApJ, 426, L69 CrossRefGoogle Scholar
Udalski, A. et al., 1994b, Acta Astron., 44, 165 Google Scholar
Udalski, A. et al., 1994c, Acta Astron., 44, 227 Google Scholar
Udalski, A. et al., 1994d, ApJ, 436, L103 CrossRefGoogle Scholar
Udalski, A. et al., 1994e, Acta Astron., 44, 317 Google Scholar
Udalski, A. et al., 1995, Acta Astron., 45, 1 Google Scholar
Wambsganss, J. & Paczyński, B., 1992, ApJ, 397, L1 CrossRefGoogle Scholar
Zhao, H. S., Spergel, D. N., & Rich, R. M., 1995, ApJ, 440, L13 CrossRefGoogle Scholar
Zucker, S. & Mazeh, T., 1994, ApJ, 420, 806 CrossRefGoogle Scholar