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 @).
May 15, Tuesday at 11:00 am
" The Galaxy Luminosity Functions down to M~-10 in the Hydra I Cluster "
(Grad. Univ. Advanced Studies)
Dwarf galaxies account for a large share of cluster galaxies and
should be closely related to the formation and evolution of clusters.
Despite the obvious importance, however, the number of very faint
(douwn to M~-10) cluster samples available to date is limited and
properties of such faint galaxies remain unclear.
In order to reveal properties of faint cluster dwarfs, we derive
very faint-end slopes of the galaxy luminosity functions (LFs) in
the Hydra I cluster at z=0.0126, for which such a very faint galaxy
population, at M~-10, has not been previonsly surveyed.
We find that the LF of the entire population has a slightly steeper
slope (alpha~-1.6) in the range of -20 < M < -10 than those reported for
other clusters in slightly brighter ranges.
The LF shows a significant upturn at M~-16 as is seen in several other
nearby clusters, but not in the field.
We also find that red galaxies dominate over blue galaxies in the
Hydra I down to M=-10.
The upturn in the faint-end slope of the LF is likely due to the
generation of the faint red galaxies, which presumably related to
Strong tidal interactions (such as harassment) should occure frequently
in clusters, and many galaxies are probably transformed into red galaxies,
which possibly form the observed upturn.
In this talk, I will present our results of LFs in the two different regions
of the Hydra I in B- and Rc-bands using the Subaru Suprime-Cam photometry.
Seminars are also held at JAC,