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I am a graduate student in the Department of Astronomy, Graduate School of Science, The University of Tokyo / Kavli IPMU.
I am studying complex evolutionary processes of galaxies to understand how diverse galaxies in the present universe were born and evolved.
Research Topic
Research Topic
Galaxy evolution
through rare galaxies
Galaxy evolution
through rare galaxies
I'm advancing efforts to identify "rejuvenated galaxies," which have resumed star formation after an earlier quenching phase, as well as to discover rare galaxy populations using machine learning approaches such as anomaly detection.
Publications:
・Tanaka et al. 2022
"Where's Swimmy?: Mining unique color features buried in galaxies by deep anomaly detection using Subaru Hyper Suprime-Cam data"
・Tanaka et al., 2024
"HINOTORI I: The nature of rejuvenation galaxies"
AGN and host galaxies
AGN and host galaxies
Active galactic nuclei (AGN) are objects whose center region shines as bright as the main galaxy component due to the release of gravitational energy when matter accretes into the supermassive black hole at the center of the galaxy. By comparing galaxies with AGN with those without AGN, we are discussing the impact of AGN on galaxy evolution.
Publications:
・Tanaka et al., 2025
"The MBH−M∗ relation up to z∼2 through decomposition of COSMOS-Web NIRCam images"
・Tanaka et al., 2024
"Crimson Behemoth: a Massive Clumpy Structure Hosting a Dusty AGN at z=4.91"
・Ito, Tanaka et al. 2025
"Black hole mass of a quiescent galaxy hosting a Type 1 AGN at z = 2.09: implications for black hole-galaxy coevolution and AGN quenching at high redshift"
"Little Red Dots"
"Little Red Dots"
Recent observations with the James Webb Space Telescope (JWST) have uncovered a new high-redshift population, dubbed "Little Red Dots" (LRDs), which differ markedly from any previously known population. These enigmatic sources may be linked to the earliest phases of supermassive black hole formation. I focus on expanding the search for LRDs and exploring their physical nature and evolutionary history.
Publications:
・Tanaka et al., 2024
"Discovery of dual ``little red dots'' indicates excess clustering on kilo-parsec scales"
・Tanaka et al., 2025
"Discovery of a Little Red Dot candidate at z>10 in COSMOS-Web based on MIRI-NIRCam selection"
Major Updates
Major Updates
Aug 2025: A paper on the first z>~10 LRDs candidate selected from the MIRI-NIRCam joint dataset was posted on arXiv.
Mar 2025: Received the University of Tokyo Graduate School of Science Research Award.
Jan 2025: A paper on the statistical exploration of the relationship between high-redshift (z~1-3) AGNs and their host galaxies was published in ApJ.
Dec 2024: A paper on high-z merging AGNs (dual LRDs) discovered from JWST imaging data was posted on arXiv.
Dec 2024: A paper on the discovery of a high-redshift (z=4.91) AGN surrounded by a clumpy massive structure was published in PASJ.
Mar 2024: Delivered an invited talk at the Dense Gas in Nearby Galaxies - ALMA Workshop.
Jan 2024: A paper on the search for rejuvenated galaxies was published in PASJ.
Mar 2023: Received the University of Tokyo School of Science Academic Encouragement Award.
Jan 2023 - 2023/02: Visited the Kavli Institute for Cosmology, Cambridge, using UGRASP2022.
Jan 2022: A paper on anomaly detection using imaging data from the Subaru Telescope was published in PASJ.
CV
CV
CV.pdf Contact
Contact
mail : takumi.tanaka <at> ipmu.jp
Department of Astronomy, School of Science, The University of Tokyo
7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
Kavli Institute for the Physics and Mathematics of the Universe, The University of Tokyo
5-1-5 Kashiwanoha, Kashiwa, Tokyo, 277-8583, Japan
Center for Data-Driven Discovery, Kavli IPMU (WPI), UTIAS, The University of Tokyo
5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8583, Japan
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