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 Masayuki
Akiyama by email.
Augast 11, Monday at 10:00am
"A spectro-astrometric study of pre-main sequence stars
--- Probing AU-scale structure --- "
Michihiro Takami (University of Hertfordshire, UK)
The circumstellar environment within 10 AU of young stars is of particular
interest for studies of star and planet formation. In this region, the star
accretes the material from the circumstellar disk, and drives an energetic
jet/wind. In the circumstellar disk, planets may be growing and tidally
interacting with the circumstellar environment. In a significant number of
objects, this region also contains a stellar companion. The population, mass
distribution, and orbital parameters of these companions could give useful
constraints on the understanding of binary formation. However, even the Hubble
Space Telescope or adaptive optics on 10-m telescopes cannot resolve this
scale in the nearest star-forming regions.
To obtain spatial information at such high resolutions, we use the technique
of ``spectro-astrometry''. By use of a standard long-slit spectrograph, the
seeing position relative to the continuum is measured in emission/absorption
features with an extremely high accuracy (~1 mas). We have proved that this
method is capable of discovering pre-main sequence binaries, determining
kinematics of outflows and providing evidence for gaps in circumstellar disks
--- all down to AU scales. I summarise our progress to date, and present
some recent results obtained at the SUBARU 8.2-m telescope.
Seminars are also held at JAC,