Visit ASIAA Homepage Deadline: August 8, 2013
East-Asian ALMA Science Workshop 2013
September 2-4, 2013
ASIAA Auditorium, Taipei, Taiwan

Oral Presentation

Measuring the Black Hole Mass in Ultra-luminous X-ray Sources using Molecular Emission Lines in X-ray Dominated Region

Ken Ebisawa, Satoru Iguchi, Masao Saito, Tessei Yoshida, Toshihiro Kawaguchi, Yuichi Terashima, Naoki Isobe

Ultra-luminous X-ray Sources (ULX) are bright (10^{40}-10^{42} erg/s)
compact X-ray sources often found in nearby spiral galaxies.
Their luminosities exceed the Eddington limits of Galactic
compact objects (10^{38} erg/s for one-solar mass),
so ULXs are considered to be either massive stellar black holes
(10~30 Msolar) shining at super-Eddington luminosities, or
"intermediate mass black holes" (>100 M solar) with
sub-Eddington luminosities. Both models may equally
explain the X-ray data, thus the black hole mass is, unfortunately, not constrained from X-rays.
Recently, it is found that intensities of emission
lines of some molecules, such as SiO and CN, are enhanced in X-ray dominated
region (XDR) in AGNs. XDR is also expected to be formed around ULXs, and
we may constrain the black hole mass by measuring
velocity maps of those strong emission lines using ALMA.