Hello. I am an associate professor at Osaka University, 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 coronal cosmic-ray energy budget in AGNs is accepted by PASJ.

 2024年06月30日に投稿  |  1 分間  |  138 言葉  |  

Title: Upper Limit on the Coronal Cosmic Ray Energy Budget in Seyfert Galaxies. Authors: Yoshiyuki Inoue, Shinsuke Takasao, Dmitry Khangulyan The IceCube collaboration has reported possible detections of high-energy neutrinos from nearby Seyfert galaxies. While central hot coronae are proposed as the primary neutrino production site, the exact coronal cosmic-ray energy budget has been loosely constrained. In this study, we propose a new stringent upper bound on the coronal cosmic-ray energy budget of Seyfert galaxies, considering both accretion dynamics and observed properties of radio-quiet Seyfert galaxies. [続きを読む]
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Our paper on cosmic rays in cosmological filaments is accepted by Universe.

 2024年06月27日に投稿  |  2 分間  |  279 言葉  |  

Title: Energetic Particles and High-Energy Processes in Cosmological Filaments and Their Astronomical Implications. Authors: Kinwah Wu, Ellis R. Owen, Qin Han, Yoshiyuki Inoue, Lilian Luo Large-scale cosmic filaments connect galaxies, clusters and voids. They are permeated by magnetic fields with a variety of topologies. Cosmic rays with energies up to 1020eV can be produced in astrophysical environments associated with star-formation and AGN activities. The fate of these cosmic rays in filaments, which cannot be directly observed on Earth, are rarely studied. [続きを読む]
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Our paper on multi-epoch X-ray spectral analysis of Cen A is accepted by PASJ.

 2024年06月14日に投稿  |  1 分間  |  209 言葉  |  

Title: Multi-epoch X-ray spectral analysis of Centaurus A: revealing new constraints on iron emission line origins . Authors: Toshiya Iwata, Atsushi Tanimoto, Hirokazu Odaka, Aya Bamba, Yoshiyuki Inoue, Kouichi Hagino We conduct X-ray reverberation mapping and spectral analysis of the radio galaxy Centaurus A to uncover its central structure. We compare the light curve of the hard X-ray continuum from Swift Burst Alert Telescope observations with that of the Fe Kα fluorescence line, derived from the Nuclear Spectroscopic Telescope Array (NuSTAR), Suzaku, XMM-Newton, and Swift X-ray Telescope observations. [続きを読む]
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Our paper on radio emission from AGN disk winds is accepted by ApJ.

 2024年04月02日に投稿  |  2 分間  |  235 言葉  |  

Title: Deciphering Radio Emissions from Accretion Disk Winds in Radio-Quiet Active Galactic Nuclei. Authors: Tomoya Yamada, Nobuyuki Sakai, Yoshiyuki Inoue, Tomonari Michiyama Unraveling the origins of radio emissions from radio-quiet active galactic nuclei (RQ AGNs) remains a pivotal challenge in astrophysics. One potential source of this radiation is the shock interaction between AGN disk winds and the interstellar medium (ISM). To understand this phenomenon, we construct a spherical, one-zone, and self-similar expansion model of shock structure between ultra-fast outflows (UFOs) and the ISM. [続きを読む]
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Graduation Day

 2024年03月25日に投稿  |  1 分間  |  157 言葉  |  

We are proud to announce the graduation of our esteemed students on March 25th, marking a significant milestone in their academic careers. Our master’s students, Kaoru Yanagisawa and Tomoya Yamada, were awarded their Master’s degrees, showcasing their exceptional skills and dedication in their respective fields of study. On the same day, our undergraduate student, Pan Yue, received her Bachelor’s degree, demonstrating her hard work and commitment to her studies. Thesis titles: [続きを読む]
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Our paper on Millimeter Time Variability in the Gamma-Ray Detected Seyfert Galaxy GRS 1734-292 is accepted by ApJ.

 2024年03月01日に投稿  |  2 分間  |  242 言葉  |  

Title: ALMA Confirmation of Millimeter Time Variability in the Gamma-Ray Detected Seyfert Galaxy GRS 1734-292. Authors: Tomonari Michiyama, Yoshiyuki Inoue, Akihiro Doi, Tomoya Yamada, Yasushi Fukazawa, Hidetoshi Kubo, Samuel Barnier GRS 1734-292 is a radio-quiet galaxy, exhibiting neither intense starburst nor jet activities. However, Fermi-LAT detected this object in the GeV band. The origin of non-thermal activity in this Seyfert galaxy is an intriguing question. We report Atacama Large Millimeter/submillimeter Array (ALMA) observations of GRS 1734-292 at frequencies of 97. [続きを読む]
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Our paper on gamma-ray emission in NGC 4151 is accepted by PASJ.

 2023年09月29日に投稿  |  1 分間  |  149 言葉  |  

Title: Gamma-ray emission in the Seyfert galaxy NGC 4151: Investigating the role of jet and coronal activities. Authors: Yoshiyuki Inoue, Dmitry Khangulyan NGC 4151, a nearby Seyfert galaxy, has recently been reported to emit gamma rays in the GeV range, posing an intriguing astrophysical mystery. The star formation rate of NGC 4151 is too low to explain the observed GeV flux, but the galaxy is known for its coronal activity in X-ray and jet activity in radio. [続きを読む]
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Our review paper on cosmic-ray processes in Galactic ecosystems is accepted by Galaxies.

 2023年07月12日に投稿  |  2 分間  |  217 言葉  |  

Title: High energy emission component, population, and contribution to the extragalactic gamma-ray background of gamma-ray emitting radio galaxies. Authors: Ellis R. Owen, Kinwah Wu, Yoshiyuki Inoue, H.-Y. Karen Yang, Alison M. W. Mitchell Galaxy evolution is an important topic, and our physical understanding must be complete to establish a correct picture. This includes a thorough treatment of feedback. The effects of thermal-mechanical and radiative feedback have been widely considered, however cosmic rays (CRs) are also powerful energy carriers in galactic ecosystems. [続きを読む]
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Our paper on the cm-mm radio spectrum of NGC 1068 is accepted by PASJ.

 2023年06月26日に投稿  |  2 分間  |  217 言葉  |  

Title: The centimeter-to-submillimeter broad-band radio spectrum of the central compact component in a nearby type-II Seyfert galaxy NGC 1068. Authors: Tomonari Michiyama, Yoshiyuki Inoue, Akihiro Doi We analyze all the available Atacama Large Millimeter / submillimeter Array archival data of the nearby Type-II Seyfert galaxy NGC 1068, including new 100 GHz data with the angular resolution of 0\farcs05, which was not included in previous continuum spectral analysis. By combining with the literature data based on the Very Large Array, we investigate the broadband radio continuum spectrum of the central ≲7 pc region of NGC 1068. [続きを読む]
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