Industrial-Scale Mass Measurements of Isolated Black Holes

Abstract

I show that industrial-scale mass measurement of isolated black holes (BHs) can be achieved by combining a high-cadence, wide-field microlensing survey such as KMTNet, observations from a parallax satellite in solar orbit, and VLTI GRAVITY+ interferometry. I show that these can yield precision measurements of microlens parallaxes down to ${\pi }_{\mathrm{E}}\sim 0.01$ and Einstein radii down to ${\theta }_{\mathrm{E}}\sim 1$mas. These limits correspond to BH masses $M\sim 12M_{\odot }$, deep in the Galactic bulge, with lens-source separations of $D_{LS}\sim 0.6$kpc, and they include all BHs in the Galactic disk. I carry out detailed analyses of simulations that explore many aspects of the measurement process, including the decisions on whether to carry out VLTI measurements for each long-event candidate. I show that the combination of ground-based and space-based light curves of BH events will automatically exclude the spurious "large parallax" solutions that arise from the standard (Refsdal 1966) analysis, except for the high-magnification events, for which other methods can be applied. The remaining two-fold degeneracy can always be broken by conducting a second VLTI measurement, and I show how to identify the relatively rare cases that this is required.

39 pages, 7 figures, to be submitted to AAS Journals

Cited by in corpus (1)

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