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
(Tomonori Usuda, Kumiko S. Usuda, Masayuki Akiyama)
by email : sseminar_at_subaru.naoj.org (please change"_at" to @).
October 09, Monday at 10:30am
" Polycyclic Aromatic Hydrocarbons in various astrophysical environment "
Itsuki Sakon (University of Tokyo)
Polycyclic aromatic hydrocarbons(PAHs) are thought to be the carriers of the
unidentified infrared (UIR) bands, which have been observed in various
astrophysical environments including HII regions, Reflection Nebulae, Planetary
Nebulae, diffuse ISM, and external galaxies even at the distance of z=2.8.
Their ubiquitous presence suggests that the diagnostic use of the UIR features
is quite useful to probe the interstellar environment even in a distant galaxy.
In the first half of my talk, I am planing to show you our recent result on the
mid-infrared spectroscopy of non-isolated Herbig Ae/Be object MWC1080 using
Subaru/COMICS and discuss the ionization of PAHs around the central B0 star
traced by the UIR 11.0um/11.2um ratio. In the last half, I would like to
introduce our recent results on the mid-infrared observation of super star
clusters in two blue compact dwarf galaxies, Henize 2-10 and IIZw40 using
Subaru/COMICS. I especially focus on the properties of PAHs to understand their
evolution in such an active and young starburst environment. Through these
attempts, we aim to demonstrate the formation, evolution, and destruction
process of PAHs andto make the uqbiquitous PAH features as the valid measure of
the physical quantities such as the interstellar radiation strength, the
electron density, etc.
" Detection of PAH emission features in nearby dusty elliptical galaxies "
Hidehiro Kaneda (ISAS / JAXA)
According to the current understanding, the presence of a considerable amount
of dust in elliptical galaxies is quite common. Studies with ISO and Spitzer
suggest even the presence of PAHs emission features in the SED of several
elliptical galaxies. Hot ionized gas filling the interstellar space of
elliptical galaxies, however, is expected to easily destroy such very small
particles through sputtering by plasma ions.
In this talk, I present the results of mid-IR spectroscopic observations
of X-ray-emitting nearby dusty elliptical galaxies with the Spitzer Infrared
Spectrograph (IRS). We have succeeded in detection of the PAH emission
from the elliptical galaxies. The observed spectra seem to be quite unusual;
the PAH features at 6.2, 7.7, and 8.6 um are very faint in contrast to
prominent emission features at 11.3 and/or 12.7 um, which may reflect peculiar
physical conditions of the ISM. The detection of the PAHs provides strong
constraints on the evolution scenarios of the ISM of elliptical galaxies.
" Spatial Evolution of UIR bands in Red Rectangle "
In-Ok Song (Kyung Hee University)
Seminars are also held at JAC,