Details

Autor(en) / Beteiligte

• Hamadache, C.
• Le Guillou, L.
• Tisserand, P.
• Afonso, C.
• Albert, J. N.
• Andersen, J.
• Ansari, R.
• Aubourg, É.
• Bareyre, P.
• Beaulieu, J. P.
• Charlot, X.
• Coutures, C.
• Ferlet, R.
• Fouqué, P.
• Glicenstein, J. F.
• Goldman, B.
• Gould, A.
• Graff, D.
• Gros, M.
• Haissinski, J.
• de Kat, J.
• Lesquoy, É.
• Loup, C.
• Magneville, C.
• Marquette, J. B.
• Maurice, É.
• Maury, A.
• Milsztajn, A.
• Moniez, M.
• Palanque-Delabrouille, N.
• Perdereau, O.
• Rahal, Y. R.
• Rich, J.
• Spiro, M.
• Vidal-Madjar, A.
• Vigroux, L.
• Zylberajch, S.

Titel

Galactic Bulge microlensing optical depth from EROS-2

Ist Teil von

• Astronomy and astrophysics (Berlin), 2006-07, Vol.454 (1), p.185-199

Ort / Verlag

Les Ulis: EDP Sciences

Erscheinungsjahr

2006

Link zum Volltext

Quelle

EZB Free E-Journals

Beschreibungen/Notizen

• Aims.We present a new EROS-2 measurement of the microlensing optical depth toward the Galactic Bulge. Methods.Light curves of $5.6\times 10^{6}$ clump-giant stars distributed over $66\,\rm deg^2$ of the Bulge were monitored during seven Bulge seasons. 120 events were found with apparent amplifications greater than 1.6 and Einstein radius crossing times in the range $5\,{\rm d}<t_{\rm E}<400\,{\rm d}$. This is the largest existing sample of clump-giant events and the first to include northern Galactic fields. Results.In the Galactic latitude range $1.4\degr<|b|<7.0\degr$, we find $\tau/10^{-6}=(1.62\,\pm 0.23)\exp\,[-a(|b|-3 \,{\rm deg})]$ with $a=(0.43\,\pm0.16)~\rm deg^{-1}$. These results are in good agreement with our previous measurement, with recent measurements of the MACHO and OGLE-II groups, and with predictions of Bulge models.