Improved Detection Rates for Close Binaries Via Astrometric Observations of Gravitational Microlensing Events

Details Improved Detection Rates for Close Binaries Via Astrometric Observations of Gravitational Microlensing Events Improved Detection Rates for Close Binaries Via Astrometric Observations of Gravitational Microlensing Events

1999-01-15

arxiv.org/abs/astro-ph/9901198v2

CNU-A&SS-10/08

Astronomy and Astrophysics

Astrophysics

total 14 pages, including 5 Figures and no Table (For figure 1, please send a request mail to cheongho@astronomy.chungbuk.ac.k

Scientific paper

10.1086/307882

In addition to constructing a Galactic matter mass function free from the bias induced by the hydrogen-burning limit, gravitational microlensing allows one to construct a mass function which is less affected by the problem of unresolved binaries (Gaudi & Gould). However, even with the method of microlensing, the photometric detection of binaries is limited to binary systems with relatively large separations of $b\gtrsim 0.4$ of their combined Einstein ring radius, and thus the mass function is still not totally free from the problem of unresolved binaries. In this paper, we show that by detecting distortions of the astrometric ellipse of a microlensing event with high precision instruments such as the {\it Space Interferometry Mission}, one can detect close binaries at a much higher rate than by the photometric method. We find that by astrometrically observing microlensing events, $\sim 50%$ of binaries with separations of $0.1r_{\rm E}$ can be detected with the detection threshold of 3%. The proposed astrometric method is especially efficient at detecting very close binaries. With a detection threshold of 3% and a rate of 10%, one can astrometrically detect binaries with separations down to $\sim 0.01r_{\rm E}$.

Affiliated with

Also associated with

No associations

Rating

Improved Detection Rates for Close Binaries Via Astrometric Observations of Gravitational Microlensing Events 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 Improved Detection Rates for Close Binaries Via Astrometric Observations of Gravitational Microlensing Events, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Improved Detection Rates for Close Binaries Via Astrometric Observations of Gravitational Microlensing Events will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-597309