A Binary Lensing Event Toward the LMC: Observations and Dark Matter Implications

Details A Binary Lensing Event Toward the LMC: Observations and Dark Matter Implications A Binary Lensing Event Toward the LMC: Observations and Dark Matter Implications

1996-06-04

arxiv.org/abs/astro-ph/9606012v1

Nucl.Phys.Proc.Suppl. 51B (1996) 152-156

Astronomy and Astrophysics

Astrophysics

5 pages, 3 postscript figures included; To appear in the Proceedings of the Dark Matter '96 Conference held in Santa Monica, C

Scientific paper

10.1016/S0920-5632(96)00497-5

The MACHO collaboration has recently analyzed 2.1 years of photometric data for about 8.5 million stars in the Large Magellanic Cloud (LMC). This analysis has revealed 8 candidate microlensing events and a total microlensing optical depth of $\tau_{meas} = 2.9 +1.4/-0.9 \times 10^{-7}$. This significantly exceeds the number of events (1.1) and the microlensing optical depth predicted from known stellar populations: $\tau_{back} = 5.4\times 10^{-8}$, but it is consistent with models in which about half of the standard dark halo mass is composed of Machos of mass $\sim 0.5 \msun$. One of these 8 events appears to be a binary lensing event with a caustic crossing that is partially resolved which allows us to estimate the distance to the lenses. If the source star is not a short period binary star, then we show that the lens system is very likely to reside in the LMC. However, if we assume that the optical depth for LMC-LMC lensing is large enough to account for our entire lensing signal, then the binary event does not appear to be consistent with lensing of a single LMC source star by a binary residing in the LMC. Thus, while the binary lens may indeed reside in the LMC, there is no indication that most of the lenses reside in the LMC.

Affiliated with

Also associated with

No associations

Rating

A Binary Lensing Event Toward the LMC: Observations and Dark Matter Implications 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 A Binary Lensing Event Toward the LMC: Observations and Dark Matter Implications, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A Binary Lensing Event Toward the LMC: Observations and Dark Matter Implications will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-409091