発表者
吉浦伸太郎
日程/場所
5月13日(水)11:00-@ES606
概要
After the birth of the Universe, the universe went through three important
epochs: the Dark Ages, when no astronomical objects had yet formed; the
Cosmic Dawn, when the first stars were born; and the Epoch of Reionization,
when ultraviolet radiation from young galaxies ionized hydrogen in
intergalactic medium. Although these epochs are crucial for understanding
the early history of galaxy formation and cosmology, many aspects remain
observationally unexplored.
One promising approach is to observe the 21-cm line, a radio signal emitted
by neutral hydrogen atoms at a rest frequency of approximately 1420 MHz. By
detecting the signal from hydrogen that filled the early Universe, we can
probe the cosmology of the Dark Ages and the formation of the first cosmic
structures. Due to the expansion of the Universe, this 21-cm signal is
redshifted to lower frequencies and is observed as low-frequency radio
signal below about 200 MHz. In particular, for the Dark Ages, the 21-cm
line is almost the only available observational probe.
To correctly extract physical information from 21-cm observations,
researchers are developing cosmological models as well as instruments and
analysis methods that can deal with foreground emission, such as radio
emission from our Galaxy. In this seminar, I will first give a brief
introduction to studies of the distant Universe using the 21-cm line. I
will then explain how the latest observational experiments are working
toward the detection of this signal.
発表者
市來淨與
日程/場所
4月15日(水)11:00-@ES606
題名
所信表明
概要
所信表明