Astronomers detect dozens of new quasars and galaxies https://phys.org/news/2017-04-astronomers-dozens-quasars-galaxies.html
A team of astronomers led by Yoshiki Matsuoka of the National Astronomical Observatory of Japan (NAOJ) has detected a treasure trove
of new high-redshift quasars (or quasi-stellar objects) and luminous galaxies. The newly found objects could be very important for
our understanding of the early universe. The findings were presented Apr. 19 in a paper published on arXiv.org.
High-redshift quasars and galaxies (at redshift higher than 5.0) are useful probes of the early universe in many respects. They offer
essential clues on the evolution of the intergalactic medium, quasar evolution, early supermassive black hole growth, as well as
evolution of galaxies through cosmic times. Generally speaking, they enable scientists to study the universe when it looked much
different than it does today.
Recently, Matsuoka's team has presented the results from the Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs) project,
which uses multi-band photometry data provided by the Hyper Suprime-Cam (HSC) Subaru Strategic Program (SSP) survey. HSC is a wide-field
camera installed on the Subaru 8.2 m telescope located at the summit of Maunakea, Hawaii and operated by NAOJ. The researchers selected
nearly 50 photometric candidates from the HSC-SSP source catalog and then observed them with spectrographs on the Subaru Telescope and
the Gran Telescopio Canarias (GTC), located on the island on the Canary Island of La Palma, Spain.
The observations resulted in the identification of 24 new quasars and eight new luminous galaxies at redshift between 5.7 and 6.8.