The existence of intermediate-mass black holes (IMBHs) in globular clusters has been debated. One possible way to form IMBHs in globular clusters is by repeating the merger of BHs in star clusters. However, gravitational-wave recoils kick the IMBHs out from the host globular clusters before they reach 500 Msun. Another...
NGC 253 is an archetypal starburst galaxy in the nearby universe, whose relative proximity (D ~ 3.5 Mpc) makes it an ideal target for studying the physical and chemical environments conducive to highly active star formation (SF). In particular, its similarity to the Milky Way (MW), traditionally understood as a quiescent...
We present the latest observations of the early growth of active supermassive black holes (=quasars) in the early Universe, less than a billion years after the Big Bang, mainly using the Subaru Telescope and the James Webb Space Telescope (JWST). The search for distant quasars has been active since the...
The outermost atmosphere of the Sun (the corona) reaches temperatures hundreds of times hotter than its surface (the photosphere), exceeding 1 million degrees. This issue of solar corona heating has been an unresolved problem since the 1930s and is a main target of the SOLAR-C mission. Furthermore, the solar corona...
Extragalactic astronomy is currently in an exciting period. Observing high-redshift galaxies allows us to directly see galaxies in the distant past, dating back to when the Universe was only nearly a few hundred million years old. This remarkable feature has led astronomers to dedicate significant efforts toward finding and studying...
(Ultra)luminous infrared galaxies (= (U)LIRGs) at z=0 form stars 10-100 times more efficiently than z=0 main sequence (MS) galaxies, which is explained by nearby (U)LIRGs being gas-rich merging galaxies. Numerical simulations and sub-kpc observations clearly show that tidal interaction between gas-rich progenitors is condensing gas and triggering subsequent starburst activity...
Active Galactic Nucleus (AGN) is a phenomenon in which the accretion of mass onto a supermassive black hole (SMBH) converts its gravitational energy into radiant energy, causing the center of the galaxy to glow with a solar intensity of about $10^{9}$. AGNs emit gamma rays from radio waves, which have...
Most of the matter in the universe is dominated by dark matter. However, its nature remains a mystery and is one of the biggest problems in modern physics. Various approaches have been taken in a wide range of fields from particle physics to astronomy to elucidate the nature of this...
The existence of intermediate-mass black holes (IMBHs) in globular clusters has been debated. One possible way to form IMBHs in globular clusters is by repeating the merger of BHs in star clusters. However, gravitational-wave recoils kick the IMBHs out from the host globular clusters before they reach 500 Msun. Another...
July 2024 15 : 30 black holes, massive stars, and star formation
NGC 253 is an archetypal starburst galaxy in the nearby universe, whose relative proximity (D ~ 3.5 Mpc) makes it an ideal target for studying the physical and chemical environments conducive to highly active star formation (SF). In particular, its similarity to the Milky Way (MW), traditionally understood as a quiescent...
June 2024 15 : 30 ALMA, starbursts, and Galactic center
We present the latest observations of the early growth of active supermassive black holes (=quasars) in the early Universe, less than a billion years after the Big Bang, mainly using the Subaru Telescope and the James Webb Space Telescope (JWST). The search for distant quasars has been active since the...
May 2024 15 : 30 SMBH, James Webb telescope, and early universe
The outermost atmosphere of the Sun (the corona) reaches temperatures hundreds of times hotter than its surface (the photosphere), exceeding 1 million degrees. This issue of solar corona heating has been an unresolved problem since the 1930s and is a main target of the SOLAR-C mission. Furthermore, the solar corona...
April 2024 15 : 30 Solar Corona, MHD, and SOLAR-C
Extragalactic astronomy is currently in an exciting period. Observing high-redshift galaxies allows us to directly see galaxies in the distant past, dating back to when the Universe was only nearly a few hundred million years old. This remarkable feature has led astronomers to dedicate significant efforts toward finding and studying...
March 2024 15 : 30 ALMA, James Webb telescope, and high-z galaxies
(Ultra)luminous infrared galaxies (= (U)LIRGs) at z=0 form stars 10-100 times more efficiently than z=0 main sequence (MS) galaxies, which is explained by nearby (U)LIRGs being gas-rich merging galaxies. Numerical simulations and sub-kpc observations clearly show that tidal interaction between gas-rich progenitors is condensing gas and triggering subsequent starburst activity...
January 2024 14 : 30 galaxy evolution, molecular clouds, and AGN feedback
Active Galactic Nucleus (AGN) is a phenomenon in which the accretion of mass onto a supermassive black hole (SMBH) converts its gravitational energy into radiant energy, causing the center of the galaxy to glow with a solar intensity of about $10^{9}$. AGNs emit gamma rays from radio waves, which have...
December 2023 16 : 30 AGN, seyfert galaxies, and X-rays
Most of the matter in the universe is dominated by dark matter. However, its nature remains a mystery and is one of the biggest problems in modern physics. Various approaches have been taken in a wide range of fields from particle physics to astronomy to elucidate the nature of this...
November 2023 15 : 30 dark matter, dwarf galaxies, and Subaru
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