Ayumi Takahashi
I am a student in the Graduate school of Science and Engineering at Ehime University, Japan, and working with Assosiate Professor Yoshiki Matsuoka to use Optical/NIR data. I am interested in the growth of super massive black holes at the early universe and also interest in their cosmological evolution. Before I came corrent school, I belonged to the Department of Applied Physics at Kogakuin University and was earned my bachelor's degree from that school in 2019.
Research projects and interests
"Co-evolution" between galaxies and central super massive black holes (SMBHs)
Dispite more than 300 quasars have discovered in the early universe, it is unclear how such massive central objects form and grow in a short time. "Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs)" project I join from 2019 has constructed more than 180 low-luminosity quasars at z ~ 6 - 7 (details are here), based on the Subaru HSC-SSP that carried out deep (r ~ 25 mag) and wide-feild (1400 deg^2) surveys. As part of the project, I study the properties of low-luminosity, normal quasars at high-z universe statistically, measured the distribution of BH masses of our sample and compared spectral properties with low-z quasars (SDSS quasars) using optical spectral data.
Grants
E.U. (Ehime Univ.) advanced research fellowship (April 2022 - March 2024, 15K USD/year)Published Papers
-Contribution
Subaru High-z Exploration of Low-luminosity Quasars (SHELLQs). XVI. 69 New Quasars at 5.8 < z < 7.0: Matsuoka, Y., et al. 2022, ApJS, 259:18
Accepted Observing Proposals
Subaru/IRCS (S22B, Service, 3hrs) "Spectroscopic confirmation of a very low-mass quasars with super Eddington accretion at z > 6"
International Conference Lecture
- A.Takahashi, et al., ”SHELLQs High-z Quasars Explored via SDSS Counterparts Spectra”, Hyper Suprime-Cam AGN face-to-face meeting, 23 January -24 January,2020, Kyoto Univeristy (Oral+ Poster)
- A.Takahashi, et al., ”Black-hoke mass distribution of high-z low-luminosity quasars estimated via spectral comparison with low-z quasars”, 44th COSPAER Scientific Assembly, 16 July - 24 July, 0222, Athens Greece (Oral)
Domestic Conference Lecture
- A.Takahashi et al.,"Investigation of High-z quasars based on comparison with spectra of SDSS low-z quasars" the frontiers of astrophysics workshop 14 January, 2020, Kogakuin University (Oral)
- A.Takahashi et al., "Predicting species of High-z and low luminosity Quasars"、Astronomical Society of Japan (Spring) Tsukuba University, 16 - 19 March, 2020 (Oral+Poster)
- A.Takahashi et al.,"Predicting of High-z and low luminosity quasars based on spectra data, Astronomical Society of Japan (Online), 16-19 January, 2021(Oral)
- A.Takahashi et al. "Measuring the distribution of black hole masses of low luminosity quasars at high-z based on low-z spectral data", The First Stars and the First Galaxies, 16 February at Kyoto Univ. (Tokyo-office), 17-18 February at Tohoku Univ. (Tokyo-office), 2022 (Oral)