Zobrazeno 1 - 10
of 119
pro vyhledávání: '"Koh Takahashi"'
Autor:
Hiroto Yanagisawa, Masami Ouchi, Kuria Watanabe, Akinori Matsumoto, Kimihiko Nakajima, Hidenobu Yajima, Kentaro Nagamine, Koh Takahashi, Minami Nakane, Nozomu Tominaga, Hiroya Umeda, Hajime Fukushima, Yuichi Harikane, Yuki Isobe, Yoshiaki Ono, Yi Xu, Yechi Zhang
Publikováno v:
The Astrophysical Journal, Vol 974, Iss 2, p 266 (2024)
We present He i /H β flux and He/H abundance ratios in three James Webb Space Telescope galaxies with significant constraints on N/O abundance ratios, GS-NDG-9422, RXCJ2248-ID, and GLASS150008 at z ∼ 6 mostly with the spectroscopic coverage from H
Externí odkaz:
https://doaj.org/article/eb09a0df57fb453e846492ddc1992042
Autor:
Kuria Watanabe, Masami Ouchi, Kimihiko Nakajima, Yuki Isobe, Nozomu Tominaga, Akihiro Suzuki, Miho N. Ishigaki, Ken’ichi Nomoto, Koh Takahashi, Yuichi Harikane, Shun Hatano, Haruka Kusakabe, Takashi J. Moriya, Moka Nishigaki, Yoshiaki Ono, Masato Onodera, Yuma Sugahara
Publikováno v:
The Astrophysical Journal, Vol 962, Iss 1, p 50 (2024)
We present gas-phase elemental abundance ratios of thirteen local extremely metal-poor galaxies (EMPGs), including our new Keck/LRIS spectroscopy determinations together with 33 James Webb Space Telescope z ∼ 4–10 star-forming galaxies in the lit
Externí odkaz:
https://doaj.org/article/6635069359c34b39a702013d4d0143f9
Publikováno v:
The Astrophysical Journal, Vol 961, Iss 1, p 47 (2024)
Some supernovae (SNe) are powered by the collision of the SN ejecta with dense circumstellar matter (CSM). Their emission spectra show characteristic line shapes of combined broad emission and narrow P Cygni lines, which should closely relate to the
Externí odkaz:
https://doaj.org/article/718bcdd231b04f19af5faae786f3e914
Publikováno v:
The Astrophysical Journal, Vol 945, Iss 1, p 19 (2023)
Massive stars are linked to diverse astronomical processes and objects including star formation, supernovae and their remnants, cosmic rays, interstellar media, and galaxy evolution. Understanding their properties is of primary importance for modern
Externí odkaz:
https://doaj.org/article/a615bcfa72b248579548509c2902909a
Publikováno v:
Monthly Notices of the Royal Astronomical Society: Letters. 520:L72-L77
The origin of high-redshift quasars and their supermassive black hole engines is unclear. One promising solution is the collapse of a primordial supermassive star. Observational confirmation of this scenario may be challenging, but a general relativi
Publikováno v:
Monthly Notices of the Royal Astronomical Society.
The assembly of supermassive black holes poses a challenge primarily because of observed quasars at high redshift, but additionally because of the current lack of observations of intermediate mass black holes. One plausible scenario for creating supe
Publikováno v:
The Astrophysical Journal
Massive stars are linked with diverse astronomical processes and objects including star formation, supernovae and their remnants, cosmic rays, interstellar media, and galaxy evolution. Understanding their properties is of primary importance for moder
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::02e54def8ea8982ef77dd1e6036a795c
Publikováno v:
Monthly Notices of the Royal Astronomical Society. 508:828-841
We calculate the neutrino signal from Population III supermassive star (SMS) collapse using a neutrino transfer code originally developed for core-collapse supernovae and massive star collapse. Using this code, we are able to investigate the SMS mass
Publikováno v:
Monthly Notices of the Royal Astronomical Society
Observed supermassive black holes in the early Universe have several proposed formation channels in part because most of these channels are difficult to probe. One of the more promising channels, the direct collapse of a supermassive star has several
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::2972a04d79596fd8acf2c0f4f12e6634
http://arxiv.org/abs/2205.10493
http://arxiv.org/abs/2205.10493
Publikováno v:
The Astrophysical Journal
We study stellar models for Betelgeuse using the HR diagram and surface abundances as observational constraints. Previous studies on Betelgeuse have not systematically investigated the surface abundances, but we believe they can be impacted by, and t
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::a3c2b5f9e8caa6cb71974e7e75ffe8b2
http://arxiv.org/abs/2202.02953
http://arxiv.org/abs/2202.02953