Gravitational Lens Limits on Cosmological Black Holes
Abstract
We investigate the limits that gravitational lensing can place on a critical universe completely filled with randomly distributed black holes (BHs) and 1/10 filled with BHs. Specifically, we calculate the fraction of QSOs split such that two distinct images would be observable to modern telescopes. We find lens search programs at dim surface brightnesses or high QSO redshift would find a large fraction of lens-induced image pairs to have one image significantly dimmer than the other: 5 mag or more. Nondetection of QSO pairs or counterimages with modern optical telescopes can rule out cosmological BHs of M > 10^12^ M_sun_. We predict that the Hubble Space Telescope will either reduce this upper bound significantly (i.e., show there are no cosmological BHs of M > 10^9^ M_sun_) or discover a significant number of dim QSO lens induced counterimages with separations between 0.1" and 1". Similarly, very long baseline interferometry measurements have the capability of reducing the upper bound still further, down to 10^5^ M_sun_, or discovering a significant number of dim counterimages at an angular distance greater than 0.001" from bright, distant quasars.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- July 1990
- DOI:
- 10.1086/168957
- Bibcode:
- 1990ApJ...358....5N
- Keywords:
-
- Black Holes (Astronomy);
- Cosmology;
- Gravitational Lenses;
- Quasars;
- Red Shift;
- Telescopes;
- Very Long Base Interferometry;
- Astrophysics;
- BLACK HOLES;
- COSMOLOGY;
- GRAVITATIONAL LENSES;
- QUASARS