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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 12, Tuesday, at 11:00 am
" Observational study of the Cosmic Infrared Background "
Kohji Tsumura
(ISAS/JAXA)
The Cosmic Infrared Background (CIB) as an integrated history of the early universe is
important for the study of the Dark Ages, and it may include the light from the first stars
at z~10. However, previous CIB measurements suffer from residual contamination from
strong foreground emission (e.g. the zodiacal light). In this talk, our two projects for CIB
observation will be introduced. One is the Cosmic Infrared Background Experiment (CIBER),
that is a rocket experiment designed to study CIB. CIBER comprises four telescopes to
observe the absolute spectrum and spatial fluctuations of CIB. CIBER has flown four times
from 2009 to 2013, and we succeed good quality data acquisition. The other is our newly
developed method for CIB observation: the Galilean satellite occulting method. In this method,
we observe Galilean satellites eclipsed in the shadow of Jupiter as occulting disks at near-infrared
wavelengths in order to detect the absolute CIB intensity without any zodiacal light subtraction
error. The zodiacal light originates inside the orbit of Jupiter; since the Galilean satellites
in eclipse shield all light beyond the Jovian orbit, they should be detected as 'dark spots' if
the strong CIB implied by previous observations exists. The intensity deficit of this dark spot
relative to the surrounding sky directly measures the strength of the CIB, free from any assumptions
about the zodiacal light. We conducted several observations by this method with Spitzer, HST,
and Subaru IRCS+AO.
Seminars are also held at JAC,
CFHT,
and IfA.
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