Unambiguous Black Hole Mass from Polarimetry and Application to Hot Jupiters

Citation

Wiktorowicz, Sloane John (2009) Unambiguous Black Hole Mass from Polarimetry and Application to Hot Jupiters. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/3YVF-VE44. https://resolver.caltech.edu/CaltechETD:etd-03032009-092300

Abstract

A novel technique for detecting light scattered by extrasolar planets is presented that has the potential to constrain orbital inclination and planet mass. To develop this technique, I have commissioned a high precision polarimeter on the Hale 5-m telescope at Palomar Observatory. The high mass X-ray binary Cygnus X-1 has been observed, which is a proxy for extrasolar planet studies. The single scattering model of Brown et al. (1978), widely used in the literature, predicts an orbital inclination for Cygnus X-1 that is inconsistent with the lack of observed X-ray eclipses to 4σ - 5σ. Previous studies have hinted at this discrepancy, but data quality was such that the confidence in such a discrepancy was not statistically significant. My observations represent the highest precision study of this object, and they illustrate the overwhelming complexity of the supergiant/black hole system. They also call into question the validity of the Brown et al. (1978) formalism, widely used by the community, for inclination estimation in binary systems.

Extrasolar planet host stars have also been observed, and precision of order one part per million has been achieved on bright targets. Precision attained on fainter host stars is of order one part in 10^5 . While scattered light from extrasolar planets has not been conclusively detected, a planetary transit in the HD 189733 system may have been observed in polarized light. Such an event is observed to be 1,000 times weaker in polarized light than in photometry, and it indicates a planetary transit of the Southern Hemisphere of the host star. Such geometric information is difficult to determine by other methods.

The integrated polarization of the debris disk surrounding γ Ophiuchi has been observed to high precision, and the position angle of net polarization is aligned with the disk major axis as seen by the Spitzer Space Telescope. This indicates the disk is primarily composed of forward scattering dust grains larger than the wavelengths of visible light.

Finally, Neptune-mass extrasolar planets orbiting close to their host stars have been modeled to be far too warm for liquid water oceans to exist in their upper atmospheres.

Thesis Files