The Optical Gravitational Lensing Experiment. Variable Baseline Microlensing Events in the Galactic Bulge

• Autorzy: Wyrzykowski, Ł. , Udalski, A. , Mao, S. , Kubiak, M. , Szymański, M. K. , Pietrzyński, G. , Soszyński, I. , Szewczyk, O.
• Języki publikacji: EN

Abstrakty

EN

We present the first systematic search for microlensing events with variability in their baselines using data from the third phase of the Optical Gravitational Lensing Experiment (OGLE-III). A total of 137 candidates (88 new) was discovered toward the Galactic bulge. Among these, 21 have periodic oscillations in their baselines, 111 are irregular variables and 5 are potential long period detached eclipsing binaries. This is about 10% of the total number of constant baseline events. They are hence quite common and can be regarded as a new type of exotic events, which allow the determination of extra parameters of the events. We show that microlensing of variable stars may allow us to break the degeneracy between the blending parameter and magnification. We note that in some cases variability hidden in the baseline due to strong blending may be revealed in highly magnified events and resemble other exotic microlensing behavior, including planetary deviation. A new system (VEWS) for detecting ongoing variable baseline microlensing events is presented.

Słowa kluczowe

EN

gravitational lensing; Galaxy: center; Stars: oscillations; Catalogs

• Czasopismo: Acta Astronomica
• Rocznik: 2006
• Tom: Vol. 56, No. 2
• Strony: 145--169
• Opis fizyczny: Bibliogr. 26 poz., rys., tab., wykr.

Twórcy

autor

Wyrzykowski, Ł.

• Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa, Poland,
• Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK

autor

Udalski, A.

• Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa, Poland,

autor

Mao, S.

• University of Manchester, Jodrell Bank Observatory, Macclesfield, Cheshire SK11 9DL, UK,

autor

Kubiak, M.

• Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa, Poland,

autor

Szymański, M. K.

• Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa, Poland,

autor

Pietrzyński, G.

• Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa, Poland,
• Universidad de Concepción, Departamento de Fisica, Casilla 160-C, Concepción, Chile

autor

Soszyński, I.

• Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa, Poland,
• Universidad de Concepción, Departamento de Fisica, Casilla 160-C, Concepción, Chile

autor

Szewczyk, O.

• Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa, Poland,

Bibliografia

• Alard, C., and Lupton, R. 1998, Astrophys. J., 503, 325.
• Alcock, C., et al. 1993, Nature, 365, 621.
• Alcock, C., et al. 2001, Nature, 414, 617.
• An, J.H., et al. 2002, Astrophys. J., 572, 521.
• Assef, R.J., et al. 2006, Astrophys. J., accepted, astro-ph/0604147.
• Collinge, M. 2004, astro-ph/0402385.
• Devor, J. 2005, Astrophys. J., 628, 411.
• Downes, R.A., Webbink, R.F., Shara, M.M., Ritter, H., Kolb, U., and Duerbeck, H.W. 2001, P.A.S.P., 113, 764.
• Jiang, G., et al. 2004, Astrophys. J., 617, 1307.
• Lupton, R.H., Fall, S.M., Freeman, K.C., and Elson, R.A.W. 1989, Astrophys. J., 370, 201.
• Mao, S., and Paczyński, B. 1991, Astrophys. J. Letters, 374, L37.
• Mizerski, T., and Bejger, M. 2002, Acta Astron., 52, 61.
• Paczyński, B. 1986, Astrophys. J., 304, 1.
• Snodgrass, C., Horne, K., and Tsapras, Y. 2004, MNRAS, 351, 967.
• Sumi, T., Wo´zniak, P.R., Udalski, A., Szyma´nski, M., Kubiak, M., Pietrzy´nski, G., Soszy´nski, I., Żebruń, K., Szewczyk, O., Wyrzykowski, Ł., and Paczyński, B. 2006, Astrophys. J., 636, 240.
• Szymański, M., and Udalski, A. 1993, Acta Astron., 43, 91.
• Tamuz, O., Mazeh, T., and North, P. 2006, MNRAS, 367, 1521.
• Udalski, A. 2003, Acta Astron., 53, 291.
• Udalski, A., Szymański, M., Kałużny, J., Kubiak, M., Krzeminski, W., Mateo, M., Preston, G. W., and Paczyński, B. 1993, Acta Astron., 43, 289.
• Udalski, A., Szymański, M., Stanek, K. Z., Kałużny, J., Kubiak, M., Mateo, M., Krzemiński, W., Paczyński, B., and Venkat, R. 1994, Acta Astron., 44, 165.
• Udalski, A., Kubiak, M., and Szymański, M. 1997a, Acta Astron., 47, 319.
• Udalski, A., Szymański, M., Kubiak, M., Pietrzyński, G., Woźniak, P., and Żebruń, K. 1997b, Acta Astron., 47, 431.
• Woźniak, P.R. 2000, Acta Astron., 50, 421.
• Wray, J.J., Eyer, L., and Paczyński, B. 2004, MNRAS, 349, 1059.
• Wyrzykowski, Ł., Udalski, A., Kubiak, M., and Szymański, M., Żebruń, K., Soszyński, I., Woźniak, P.R., Pietrzyński, G., and Szewczyk, O. 2003, Acta Astron., 53, 1.
• Żebruń, K., Soszyński, I., Woźniak, P.R., Udalski, A., Kubiak, M., Szymański, M., Pietrzyński, G., Szewczyk, O., and Wyrzykowski, Ł. 2001, Acta Astron., 51, 317.