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Results from the Optical Gravitational Lensing Experiment (OGLE)

Published online by Cambridge University Press:  25 May 2016

B. Paczyński ,
K. Z. Stanek ,
A. Udalski ,
M. Szymański ,
J. Kałużny ,
M. Kubiak ,
M. Mateo ,
W. Krzemiński  and
G. W. Preston
B. Paczyński
Affiliation:
Princeton University Observatory Princeton, NJ 08544-1001
K. Z. Stanek
Affiliation:
Princeton University Observatory Princeton, NJ 08544-1001
A. Udalski
Affiliation:
Warsaw University Observatory Al. Ujazdowskie 4, 00-478 Warszawa, Poland
M. Szymański
Affiliation:
Warsaw University Observatory Al. Ujazdowskie 4, 00-478 Warszawa, Poland
J. Kałużny
Affiliation:
Warsaw University Observatory Al. Ujazdowskie 4, 00-478 Warszawa, Poland
M. Kubiak
Affiliation:
Warsaw University Observatory Al. Ujazdowskie 4, 00-478 Warszawa, Poland
M. Mateo
Affiliation:
Department of Astronomy, University of Michigan 821 Dennison Bldg., Ann Arbor, MI 48109-1090
W. Krzemiński
Affiliation:
Carnegie Observatories, Las Campanas Observatory Casilla 601, La Serena, Chile
G. W. Preston
Affiliation:
Carnegie Observatories, Institution of Washington 813 Santa Barbara Street, Pasadena, CA 91101

Abstract

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The analysis of the first three years of the OGLE data revealed 12 microlensing events of the Galactic bulge stars, with the characteristic time scales in the range 8.6 < t 0 < 80 days, where t 0 = RE/V. A complete sample of nine events gave the optical depth to gravitational microlensing larger than (3.3 ± 1.2) × 10–6, in excess of current theoretical estimates, indicating a much higher efficiency for microlensing by either bulge or disk lenses. The lenses are likely to be ordinary stars in the Galactic bar, which has its long axis elongated towards us. At this time we have no evidence that the OGLE events are related to dark matter. The OGLE color magnitude diagrams reveal the presence of the Galactic bar and a low density inner disk region ∼ 4 kpc in radius. A catalogue of a few thousand variable stars is in preparation.

Type
Chapter 2: Is the Milky Way a Barred Spiral Galaxy?
Information
Symposium - International Astronomical Union , Volume 169: Unsolved Problems of the Milky Way , 1996 , pp. 93 - 102
Copyright
Copyright © Kluwer 1996 

References

Alcock, C. et al. 1993, Nature, 365, 621 CrossRefGoogle Scholar
Aubourg, E. et al. 1993, Nature, 365, 623 Google Scholar
Baud, B., Habing, H. J., Matthews, H. E., & Winnberg, A. 1981, A&A, 95, 156 Google Scholar
Blommaert, J. A. D. L., van Langevelde, H. J., & Michiels, W. F. P. 1994, A&A, in press Google Scholar
Ibata, R. A., Gilmore, G., & Irwin, M. J. 1994, Nature, 370, 194.Google Scholar
Kałużny, J., Kubiak, M., Szymański, M., Udalski, A., Krzemiński, W., & Mateo, M. 1994, A&A, submitted.Google Scholar
Kiraga, M. 1994, Acta Astronomica, 44. 241.Google Scholar
Kiraga, M., & Paczyński, B. 1994, ApJ, 430, L101.Google Scholar
Mao, S., & Di Stefano, R. 1995, ApJ, 440, …CrossRefGoogle Scholar
Mateo, M., Udalski, A., Szymański, M., Kałużny, J., Kubiak, M., & Krzemiński, W. 1994, AJ, in press.Google Scholar
Paczyński, B. 1986, ApJ, 304, 1 CrossRefGoogle Scholar
Paczyński, B. 1991, ApJ, 371, L63 Google Scholar
Paczyński, B. 1994a, IAU Circular No. 5997 Google Scholar
Paczyński, B. 1994b, Acta Astron., 44. 235.Google Scholar
Paczyński, B., Stanek, K. Z., Udalski, A., Szymański, M., Kałużny, J., Kubiak, M., & Mateo, M. 1994a, AJ, 107, 2060 CrossRefGoogle Scholar
Paczyński, B., Stanek, K. Z., Udalski, A., Szymański, M., Kałużny, J., Kubiak, M., Mateo, M., & Krzemiński, W. 1994b, ApJ, in press.Google Scholar
Renzini, A. 1994, A&A, 285, L5.Google Scholar
Schechter, P. L., Mateo, M., & Saha, A. 1993, PASP, 105, 1342 Google Scholar
Stanek, K. Z. 1994, ApJ, submitted Google Scholar
Stanek, K. Z., Mateo, M., Udalski, A., Szymański, M., Kałużny, J., & Kubiak, M. 1994a, ApJ, 429, L73 Google Scholar
Stanek, K. Z., Mateo, M., Udalski, A., Szymański, M., Kałużny, J., Kubiak, M., & Krzemiński, W. 1994b, these Proceedings Google Scholar
Szymański, M., & Udalski, A. 1993, Acta Astron., 43, 91.Google Scholar
Szymański, M., Udalski, A., Kałużny, J., Kubiak, M., Mateo, M., Krzemiński, W., Preston, G.W., Paczyński, B. 1993, in: “Gravitational Lenses in the Universe”–Proceedings of 31st Liege International Astrophysical Colloquium, eds. Surdej, J. et al., p. 503.Google Scholar
Udalski, A., Szymański, M., Kałużny, J., Kubiak, M., & Mateo, M. 1992, Acta Astron., 42, 253.Google Scholar
Udalski, A., Szymański, M., Kałużny, J., Kubiak, M., Mateo, M., Preston, G. W., Krzemiński, W. & Paczyński, B. 1992, in “Galactic Bulges”, eds. Dejonghe, H. & Habing, H. (Dordrecht: Kluwer), p. 311 Google Scholar
Udalski, A., Szymański, M., Kałużny, J., Kubiak, M., Krzemiński, W., Mateo, M., Preston, G.W., & Paczyński, B. 1993a, Acta Astron., 43, 289.Google Scholar
Udalski, A., Szymański, M., Kałużny, J., Kubiak, M., & Mateo, M. 1993b, Acta Astron., 43, 69.Google Scholar
Udalski, A., Szymański, M., Kałużny, J., Kubiak, M., Mateo, M., Preston, G. W., Krzemiński, W., Stanek, K. Z. & Paczyński, B. 1993c, in “Relativistic Astrophysics and Particle Cosmology”, eds. Akerlof, C. W. & Srednicki, M. A., Ann. N.Y. Acad. Sci., 688, 626 Google Scholar
Udalski, A., Szymański, M., Kałużny, J., Kubiak, M., Mateo, M., & Krzemiński, W. 1994a, Acta Astron., 44, 1.Google Scholar
Udalski, A., Szymański, M., Kałużny, J., Kubiak, M., Mateo, M., & Krzemiński, W. 1994b, ApJ, 426, L69.Google Scholar
Udalski, A., Szymański, M., Kałużny, J., Kubiak, M., Mateo, M., Krzemiński, W., & Paczyński, B. 1994c, Acta Astron., 44, 227.Google Scholar
Udalski, A., Szymański, M., Mao, S., Di Stefano, R., Kałużny, J., Kubiak, M., Mateo, M., & Krzemiński, W. 1994d, ApJ, in press.Google Scholar
Udalski, A., Szymański, M., Stanek, K.Z., Kałużny, J., Kubiak, M., Mateo, M., Krzemiński, W., Paczyński, B., & Venkat, R. 1994e, Acta Astronom., 44, 165.Google Scholar
Zhao, H. S., Spergel, D. N., & Rich, R. M. 1994, ApJ, submitted.Google Scholar