Papers

[1st Author]

・Development of 500 GHz band waveguide circular polarization splitter and small WG flange:

Yutaka Hasegawa, Hiroyuki Maezawa, Hideo Ogawa
"Novel 500-GHz Band Waveguide Stepped Septum-Type Circular Polarizer ",
Journal of Infrared, Millimeter, and Terahertz Waves, Vol/ 42(1), pp. 1-16, 2021.
DOI : 10.1007/s10762-020-00752-9

・Implementation of 200 GHz Waveguide Frequency Diplexer to Radio Astronomy:

Hasegawa Yutaka, Asayama Shinichiro, Harada Ryohei, Tokuda Kazuki, Kimura Kimihiro, Ogawa Hideo, Onishi Toshikazu,
"Observational demonstration of a high image rejection SIS mixer receiver",
Publication of the Astronomical Society of Japan, Vol. 69(6), 2017.
DOI: 10.1093/pasj/psx098

・Development of a 200 GHz-band waveguide circular polarization splitter:

Yutaka Hasegawa, Ryohei Harada, Kazuki Tokuda, Kimihiro Kimura,Hideo Ogawa, Toshikazu Onishi, Atsushi Nishimura, Johnson Han, and Makoto Inoue,
"A New Approach to Suppress the Effect of Machining Error for Waveguide",
Journal of Infrared, Millimeter, and Terahertz Waves, Vol. 38(5), pp 638-652, 2017.
DOI: 10.1007/s10762-017-0364-3

[Co-Author]

・Observational study of the time evolution of the M87 black hole shadow by the EHT project:

Kazunori Akiyama, Antxon Alberdi, Walter Aled, et al.,
"The persistent shadow of the supermassive black hole of M 87",
Astronomy & Astrophysics, Vol. 681, A79, 2024
DOI: 10.1051/0004-6361/202347932

・Observational study of the M87 black hole shadow and jet by the EHT project:

Lu-Sen Lu, Keiichi Asada., Thomas P. Krichbaum, et al.,
"A ring-like accretion structure in M87 connecting its black hole and jet",
Nature, Vol. 616, pp. 686–690, 2023.
DOI: 10.1038/s41586-023-05843-w

・First detection of the M87 black hole shadow by the EHT project Part 1:

LThe Event Horizon Telescope Collaboration et al.,
"First M87 Event Horizon Telescope Results. I. the Shadow of the Supermassive Black Hole",
The Astrophysical Journal Letters, Vol. 875, L1, 2019.
DOI: 10.3847/2041-8213/ab0ec7

・First detection of the M87 black hole shadow by the EHT project Part 2:

The Event Horizon Telescope Collaboration et al.,
First M87 Event Horizon Telescope Results. II. Array and Instrumentation",
The Astrophysical Journal Letters, Vol. 875, L2, 2019.
DOI: 10.3847/2041-8213/ab0c96

・Development of JAXA 54 m antenna Ka-band receiver system:

Masato Tsuboi, Yutaka Hasegawa, Go Tabuchi, Yasuhiro Murata, Koji Yuchi, Tomoaki Toda, Takashi Uchimura, Kimihiro Kimura, Takashi Kasuga,
"Ka-band cryogenic low-noise receiver of the Misasa 54 m antenna for deep-space communications and radio astronomy",
Publications of the Astronomical Society of Japan, Vol. 75 (3), pp. 567–583, 2023.
DOI: 10.1093/pasj/psad020

・Optical transmission system design for the Nobeyama 45 m 72-116 GHz seven-beam receiver:

Yasumasa Yamasaki, Yutaka Hasegawa, Sho Yoneyama, et al.,
"Development of seven-beam optics using dielectric lenses for a new 72–116 GHz receiver in the Nobeyama 45 m telescope ",
Publications of the Astronomical Society of Japan, Vol. 75 (3), pp. 499–513, 2023.
DOI: 10.1093/pasj/psad015

The others: in researchmap my-page:https://researchmap.jp/espe?lang=en