Astronomy and Astrophysics – Astrophysics
Scientific paper
1997-10-17
A&A, 332 (1998) 1
Astronomy and Astrophysics
Astrophysics
10 pages, 11 figures (9 included .eps and 2 separate .gif). Numerical value for constrain on mass and distance of deflector fr
Scientific paper
We present here an analysis of the light curves of 5.3 million stars in the Small Magellanic Cloud observed by EROS (Exp\'erience de Recherche d'Objets Sombres). One star exhibits a variation that is best interpreted as due to gravitational microlensing by an unseen object. This candidate was also reported by the MACHO collaboration. Once corrected for blending, the Einstein radius crossing time is 123 days, corresponding to lensing by a Halo object of $2.6^{+8.2}_{-2.3} M_{\odot}$. The maximum magnification is a factor of 2.6. The light curve also displays a periodic modulation with a 2.5% amplitude and a period of 5.1 days. Parallax analysis of the candidate indicates that a Halo lens would need to have a mass of at least $0.3 M_{\odot}$, although a lens in the SMC could have a mass as low as $0.07 M_{\odot}}$. We estimate the optical depth for microlensing towards the SMC due to this event to be $\sim 3.3 \times 10^{-7}$, with an uncertainty dominated by Poisson statistics. We show that this optical depth corresponds to about half that expected for a spherical isothermal Galactic Halo comprised solely of such objects, and that it is consistent with SMC self-lensing if the SMC is elongated along the line-of-sight by at least 5 kpc.
collaboration EROS
et al Palanque-Delabrouille N.
No associations
LandOfFree
Microlensing towards the Small Magellanic Cloud. EROS 2 first year survey does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Microlensing towards the Small Magellanic Cloud. EROS 2 first year survey, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Microlensing towards the Small Magellanic Cloud. EROS 2 first year survey will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-83655