The Subaru Seminar is
usually held in Room 104 of the Hilo Base Facility, adjacent
to the main lobby. Everyone is welcome to attend. If you are
interested in giving a seminar, please contact Subaru seminar organizers
(Tae-Soo Pyo, Sherry Yeh, Nagayoshi Ohashi)
by email : sseminar_at_subaru.naoj.org (please change"_at" to @).
July 23, Wednesday, at 11:00 am
" Relics of Galaxy Merging: Observational Predictions for a Wandering Massive Black Hole and Accompanying Star Cluster in the M31 Halo "
Galaxies and massive black holes (BHs) are presumed to
grow via galactic merging events and subsequent BH
As a case study, we investigate the merging event
between the Andromeda galaxy (M31) and a satellite
galaxy (Miki et al. 2014).
We compute the expected observational appearance of
the massive BH and stars around it that were at
the center of the satellite galaxy prior to the merger,
and are currently wandering in the M31 halo (Kawaguchi
et al. 2014).
We demonstrate that a radiatively inefficient accretion
flow with a bolometric luminosity of a few tens of
solar luminosities develops when Hoyle-Lyttleton
accretion onto the BH is assumed.
We compute the associated broadband spectrum and show
that the radio band (observable with JVLA, ALMA and SKA)
is the best frequency range to detect the emission.
We also evaluate the mass and the luminosity of the stars
bound by the wandering BH and find that such a star
cluster is sufficiently luminous that it could correspond
to one of the star clusters found by the PAndAS survey.
The discovery of a relic massive BH wandering in a
galactic halo will provide a direct means to investigate
in detail the coevolution of galaxies and BHs.
It also means a new population of BHs (off-center
massive BHs), and offers targets for clean
BH imaging that avoids strong interstellar
scattering in the center of galaxies.
Seminars are also held at JAC,