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...
In discussing the formation and evolution of galaxies, it is essential to know how the material circulation (inflow and outflow of gas) to and from intergalactic space occurs. Observing absorption lines in the spectra of distant sources as background sources is a classical method to study the intergalactic material (IGM),...
First stars or Population III stars are the first generation of stars born in primordial gas clouds in the early universe, and are considered to have formed and evolved differently from later generations of stars (Population II/I stars) whose gas clouds contain heavy elements. Recently, with the advent of the...
X-rays are emitted from many astrophysical objects, including black holes, neutron stars, galaxies, and galaxy clusters. The Imaging X-ray Polarimeter Explorer (IXPE) satellite was launched by NASA in December 2021 to observe polarization with high sensitivity, which is the only field of X-ray astrophysics that has not yet been tackled....
Active Galactic Nuclei (AGN) shine brightly due to the gravitational energy released by mass accretion onto a supermassive black hole (SMBH). AGN are smoking guns of black hole growth. Recently, the Atacama Large Millimeter/submillimeter Array (ALMA), the world's most powerful submillimeter interferometer, has made it possible to study various properties...
A gravitational collapse supernova is an explosion of a massive star at the end of its evolution. The explosion mechanism of supernovae is an unsolved problem in astrophysics. Large-scale numerical simulation studies of supernovae overcame the "failure to reproduce the explosion" problem in the 2000s and the "failure to reproduce...
The realization of direct imaging of supermassive black holes has opened a new horizon for understanding the mysterious driving mechanism of active galactic nuclear jets. We have taken this opportunity to investigate the structure of accretion disks and jets in the vicinity of black holes through the prediction of polarization...
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
In discussing the formation and evolution of galaxies, it is essential to know how the material circulation (inflow and outflow of gas) to and from intergalactic space occurs. Observing absorption lines in the spectra of distant sources as background sources is a classical method to study the intergalactic material (IGM),...
October 2023 15 : 30 IGM, protocluster, and absorption system
First stars or Population III stars are the first generation of stars born in primordial gas clouds in the early universe, and are considered to have formed and evolved differently from later generations of stars (Population II/I stars) whose gas clouds contain heavy elements. Recently, with the advent of the...
September 2023 15 : 30 first stars, early universe, and star formation
X-rays are emitted from many astrophysical objects, including black holes, neutron stars, galaxies, and galaxy clusters. The Imaging X-ray Polarimeter Explorer (IXPE) satellite was launched by NASA in December 2021 to observe polarization with high sensitivity, which is the only field of X-ray astrophysics that has not yet been tackled....
July 2023 15 : 30 AGN, ALMA, and SMBH
Active Galactic Nuclei (AGN) shine brightly due to the gravitational energy released by mass accretion onto a supermassive black hole (SMBH). AGN are smoking guns of black hole growth. Recently, the Atacama Large Millimeter/submillimeter Array (ALMA), the world's most powerful submillimeter interferometer, has made it possible to study various properties...
June 2023 15 : 30 AGN, ALMA, and SMBH
A gravitational collapse supernova is an explosion of a massive star at the end of its evolution. The explosion mechanism of supernovae is an unsolved problem in astrophysics. Large-scale numerical simulation studies of supernovae overcame the "failure to reproduce the explosion" problem in the 2000s and the "failure to reproduce...
May 2023 15 : 30 supernovae
The realization of direct imaging of supermassive black holes has opened a new horizon for understanding the mysterious driving mechanism of active galactic nuclear jets. We have taken this opportunity to investigate the structure of accretion disks and jets in the vicinity of black holes through the prediction of polarization...
April 2023 15 : 30 AGN jets, polarization, and radiative transfer
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