Hello. I am a Senior Research Scientist at iTHEMS/RIKEN, interested in understanding the nature of black holes. As an astronomer, I have been working on both theoretical and observational astrophysics.

Our paper on the kiloparsec jet of Centaurus A is accepted by ApJL.

Title: Physical Conditions and Particle Acceleration in the Kiloparsec Jet of Centaurus A. Authors: Takahiro Sudoh, Dmitry Khangulyan, Yoshiyuki Inoue The non-thermal emission from the kiloparsec-scale jet of Centaurus~A exhibits two notable features, bright diffuse emission and many compact knots, which have been intensively studied in X-ray and radio observations. H.E.S.S. recently reported that the very-high-energy gamma-ray emission from this object is extended along the jet direction beyond a kiloparsec from the core. [続きを読む]

Our new blazar catalog paper is accepted by ApJ.

Title: Blazar Radio and Optical Survey (BROS): A catalog of blazar candidates showing flat radio spectrum and their optical identification in Pan-STARRS1 Surveys. Authors: Ryosuke Itoh, Yousuke Utsumi, Yoshiyuki Inoue, Kouji Ohta, Akihiro Doi, Tomoki Morokuma, Koji S. Kawabata, Yasuyuki T. Tanaka Utilizing the latest and the most sensitive radio and optical catalogs, we completed a new blazar candidate catalog, Blazar Radio and Optical Survey (BROS), which includes 88,211 sources located at declination $\delta>−40^\circ$ and outside the galactic plane ($|b|>10^\circ$). [続きを読む]

Our paper on the evolution of FSRQs is accepted by ApJ.

Title: Cosmological Evolution of FSRQs based on the Swift/BAT 105-month Catalog and Their Contribution to the Cosmic MeV Gamma-ray Background Radiation. Authors: Koyo Toda, Yasushi Fukazawa, Yoshiyuki Inoue We present a new X-ray luminosity function of flat-spectrum radio quasars (FSRQs) utilizing the latest Swift/BAT 105-month X-ray source catalog. Contrary to previous studies of FSRQs in the X-ray band, using the luminosity-dependent density evolution model, we find that FSRQs show evolutionary peaks at z∼1−2 depending on luminosities. [続きを読む]

A lecture talk at University of Tokyo