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 @).
November 14, Thursday, at 11:00 am
" Nature of Halpha-selected galaxies at z>2 "
Star-forming galaxies become increasingly irregular at z > 2 with clumpy structures
as well as enhancements of star formation activities. How do such distant clumpy
galaxies evolve? In numerical simulations, the clumps can migrate toward the galaxy
center as a result of their mutual interactions and of dynamical friction against
the host disk, and coalesce into a young bulge. On the other hand, strong stellar
feedback, parameterized by momentum-driven galactic winds, can disrupt clumps before
migrating towards the galaxy centers. To give observational constraints on the fate
of the clumps, we have identified a lot of clumpy galaxies from a narrow-band imaging
survey of H-alpha emitters (HAEs) at z > 2 with MOIRCS on Subaru Telescope in the
SXDF-CANDELS field, where the high-resolution near-infrared and optical images by
WFC3/ACS on HST are both publicly available. Interestingly, the colors of clumps are
often significantly different: we find the trends of having redder colors in the
galactic nuclei compared to the off-center clumps. Moreover, some clumpy HAEs are
detected with MIPS 24 um image, which strongly suggests that dusty starburst is occurring
within these galaxies. Therefore, our result implies that the intense star formation
is on-going in the red clump near the galaxy center.
Dusty starburst activity in a nuclear clump supports the scenario that the clumps
migrate to galactic center or merge with other clumps, and then such events induce an
intense star-formation like a gas-rich merger process.
Seminars are also held at JAC,