paper

A New Macho Search Strategy

arXiv:astro-ph/9409065 · doi:10.1086/175893

Abstract

I propose a radical revision in the search strategy for Massive Compact Objects (Machos) toward the Galactic bulge: monitor the entire square deg of the bulge and tune the search primarily to microlensing events of bright $M_V\lsim 2$ stars. By employing a small second telescope to follow up the events detected with low dimensionless impact parameter $β\lsim 0.2$, one could measure the proper motion of events and significantly constrain for a similar number. If, in addition, the events were followed from a Macho parallax satellite, it would be possible to measure individual masses, distances, and transverse velocities for the events with proper motions. If a fraction of the bulge is composed of low-mass objects in the range $10^{-3}\lsim M_{\rm low}/M_\odot\lsim 10^{-1}$, then mass measurements could be made for $\sim 10(ξ/0.1)(0.01 M_\odot \VEV{M_{\rm low}^{-1}})\,\rm yr^{-1}$ of these, thus allowing a direct measurement of the mass function in the sub-stellar range. In the absence of a parallax satellite, ground-based observations could significantly constrain (but not measure) Macho parallaxes. These constraints, when combined with the proper-motion measurements, would in turn constrain the mass, distance, and transverse speed of the Machos. The proposed strategy should therefore be adopted even before a parallax satellite is launched.

11 pages, no figures, PostScript file, or request PostScript file to [email protected], OSU-TA-21/94

Cited by in corpus (13)