Zobrazeno 1 - 10
of 172
pro vyhledávání: '"Masashi Chiba"'
Autor:
Sakurako Okamoto, Annette M. N. Ferguson, Nobuo Arimoto, Itsuki Ogami, Rokas Žemaitis, Masashi Chiba, Mike J. Irwin, In Sung Jang, Jin Koda, Yutaka Komiyama, Myung Gyoon Lee, Jeong Hwan Lee, Michael R. Rich, Masayuki Tanaka, Mikito Tanaka
Publikováno v:
The Astrophysical Journal Letters, Vol 967, Iss 2, p L24 (2024)
We present the discovery of NGC253-SNFC-dw1, a new satellite galaxy in the remote stellar halo of the Sculptor Group spiral, NGC 253. The system was revealed using deep, resolved star photometry obtained as part of the Subaru Near-Field Cosmology Sur
Externí odkaz:
https://doaj.org/article/6a4d3250aa674109ab3067ad3eb31b26
Autor:
Itsuki Ogami, Yutaka Komiyama, Masashi Chiba, Mikito Tanaka, Puragra Guhathakurta, Evan N. Kirby, Rosemary F. G. Wyse, Carrie Filion, Takanobu Kirihara, Miho N. Ishigaki, Kohei Hayashi
Publikováno v:
The Astrophysical Journal, Vol 971, Iss 1, p 107 (2024)
We analyze the outer regions of M33, beyond 15 kpc in projected distance from its center, using Subaru/Hyper Suprime-Cam multicolor imaging. We identify red giant branch (RGB) stars and red clump (RC) stars using the surface-gravity-sensitive NB515 f
Externí odkaz:
https://doaj.org/article/438a99fcbe224c05bd762c59f366fac6
Autor:
Yutaka Hirai, Evan N. Kirby, Masashi Chiba, Kohei Hayashi, Borja Anguiano, Takayuki R. Saitoh, Miho N. Ishigaki, Timothy C. Beers
Publikováno v:
The Astrophysical Journal, Vol 970, Iss 2, p 105 (2024)
The chemical abundances of Milky Way’s (MW's) satellites reflect their star formation histories (SFHs), yet, due to the difficulty of determining the ages of old stars, the SFHs of most satellites are poorly measured. Ongoing and upcoming surveys w
Externí odkaz:
https://doaj.org/article/b834e425161a4551863e4d31d34c6cd2
Publikováno v:
The Astrophysical Journal, Vol 953, Iss 2, p 185 (2023)
Elucidating dark matter density profiles in Galactic dwarf satellites is essential to understanding not only the quintessence of dark matter, but also the evolution of the satellites themselves. In this work, we present the current constraints on dar
Externí odkaz:
https://doaj.org/article/8eae361df8094c3f9fa1fb00b2175888
Autor:
J. Leigh Wojno, Karoline M. Gilbert, Evan N. Kirby, Ivanna Escala, Puragra Guhathakurta, Rachael L. Beaton, Jason Kalirai, Masashi Chiba, Steven R. Majewski
Publikováno v:
The Astrophysical Journal, Vol 951, Iss 1, p 12 (2023)
We present spectroscopic chemical abundances of red giant branch stars in Andromeda (M31), using medium-resolution ( R ∼ 6000) spectra obtained via the Spectroscopic and Photometric Landscape of Andromeda’s Stellar Halo survey. In addition to ind
Externí odkaz:
https://doaj.org/article/4df998deb2bc41ad91538f78358fe893
Autor:
Masashi Chiba, Kakeru Otomo, Shogo Katayama, Kanji Yoshihiro, Anna Kuwana, Haruo Kobayashi, Hiroshi Tanimoto
Publikováno v:
2022 IEEE 16th International Conference on Solid-State & Integrated Circuit Technology (ICSICT).
Autor:
Yutaka Hirai, Timothy C Beers, Masashi Chiba, Wako Aoki, Derek Shank, Takayuki R Saitoh, Takashi Okamoto, Junichiro Makino
The $r$-process-enhanced (RPE) stars provide fossil records of the assembly history of the Milky Way and the nucleosynthesis of the heaviest elements. Observations by the $R$-Process Alliance (RPA) and others have confirmed that many RPE stars are as
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::fad1c8fe31fafbced438216aa027bf9e
Autor:
Masashi Nashimoto, Masayuki Tanaka, Masashi Chiba, Kohei Hayashi, Yutaka Komiyama, Takashi Okamoto
We present a new observation of satellite galaxies around seven Milky Way (MW)-like galaxies located outside of the Local Group (LG) using Subaru/Hyper Suprime-Cam imaging data to statistically address the missing satellite problem. We select satelli
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::95936ab11768bd7980b9cfe07178763c
Autor:
Masashi Chiba
Publikováno v:
Proceedings of the International Astronomical Union. 14:83-90
We present the recent discovery of new halo structures in the Milky Way (MW) based on the Hyper Suprime-Cam (HSC) Subaru Strategic Program (SSP). HSC is a wide-field imager installed at the prime focus of the Subaru Telescope, and a 300-night survey
Autor:
Hiroko Niikura, Toshiki Kurita, Anupreeta More, Surhud More, Masahiro Takada, Masashi Chiba, Robert H. Lupton, Naoki Yasuda, Masamune Oguri, Sunao Sugiyama, Takahiro Sumi
Publikováno v:
Nature Astronomy. 3:524-534
Primordial black holes (PBHs) have long been suggested as a viable candidate for the elusive dark matter. The abundance of such PBHs has been constrained using a number of astrophysical observations, except for a hitherto unexplored mass window of MP