Hills and holes in the microlensing light curve due to plasma environment around gravitational lens. (arXiv:1910.03457v1 [gr-qc])

Hills and holes in the microlensing light curve due to plasma environment around gravitational lens. (arXiv:1910.03457v1 [gr-qc])
<a href="http://arxiv.org/find/gr-qc/1/au:+Tsupko_O/0/1/0/all/0/1">Oleg Yu. Tsupko</a>, <a href="http://arxiv.org/find/gr-qc/1/au:+Bisnovatyi_Kogan_G/0/1/0/all/0/1">Gennady S. Bisnovatyi-Kogan</a>

In this paper, we investigate the influence of the plasma surrounding the
gravitational lens on the effect of microlensing. In presence of plasma around
the lens, the deflection angle is determined by both the gravitational field of
the lens and the chromatic refraction in the inhomogeneous plasma. We calculate
microlensing curves numerically for point-mass lens surrounded by power-law
density distribution of plasma. A variety of possible curves is revealed,
depending on the plasma density and frequency of observations. If the
refractive deflection is large enough to compensate or overcome the
gravitational deflection, microlensing images can completely disappear for
observer. In this case, the remarkable effect occurs: formation of a ‘hole’
instead of a ‘hill’ in the center of microlensing light curve. In optical and
near-infrared microlensing observations, the ‘hill-hole’ effect can be
significant for lenses of small masses, which can be important for future
observational projects.

In this paper, we investigate the influence of the plasma surrounding the
gravitational lens on the effect of microlensing. In presence of plasma around
the lens, the deflection angle is determined by both the gravitational field of
the lens and the chromatic refraction in the inhomogeneous plasma. We calculate
microlensing curves numerically for point-mass lens surrounded by power-law
density distribution of plasma. A variety of possible curves is revealed,
depending on the plasma density and frequency of observations. If the
refractive deflection is large enough to compensate or overcome the
gravitational deflection, microlensing images can completely disappear for
observer. In this case, the remarkable effect occurs: formation of a ‘hole’
instead of a ‘hill’ in the center of microlensing light curve. In optical and
near-infrared microlensing observations, the ‘hill-hole’ effect can be
significant for lenses of small masses, which can be important for future
observational projects.

http://arxiv.org/icons/sfx.gif