Zobrazeno 1 - 10
of 204
pro vyhledávání: '"Hideyuki Umeda"'
Publikováno v:
The Astrophysical Journal, Vol 972, Iss 1, p 11 (2024)
SN2018ibb is a recently observed hydrogen-poor superluminous supernova that appears to be powered by the decay of 30 M _⊙ of radioactive nickel. This supernova has been suggested to show hybrid signatures of a pair-instability supernova and an inte
Externí odkaz:
https://doaj.org/article/141aeec1e5df4c3fa156337ab9a85875
Autor:
Kai Matsunaga, Hiroyuki Uchida, Rei Enokiya, Toshiki Sato, Ryo Sawada, Hideyuki Umeda, Takuto Narita, Takeshi Go Tsuru
Publikováno v:
The Astrophysical Journal, Vol 970, Iss 1, p 4 (2024)
It is generally hard to put robust constraints on progenitor masses of supernovae and supernova remnants (SNRs) observationally, while they offer tantalizing clues to understanding explosion mechanisms and mass distribution. Our recent study suggests
Externí odkaz:
https://doaj.org/article/07d84c69472b4391ac1ca99fc7d88cef
Publikováno v:
The Astrophysical Journal, Vol 965, Iss 2, p 141 (2024)
Lyman–Werner (LW) radiation photodissociating molecular hydrogen (H _2 ) influences the thermal and dynamical evolution of the Population III (Pop III) star-forming gas cloud. The effect of powerful LW radiation has been well investigated in the co
Externí odkaz:
https://doaj.org/article/ea75f0ad9249410ead0e8ae59b78feca
Autor:
Hideyuki Umeda, Chris Nagele
Publikováno v:
The Astrophysical Journal, Vol 961, Iss 2, p 146 (2024)
In this paper, we revisit metal-enriched rotating pair-instability supernovae (PISNe) models for metallicities consistent with the Small Magellanic Cloud, the Large Magellanic Cloud (LMC), and 0.1 Z _⊙ . By calculating multiple models, we intend to
Externí odkaz:
https://doaj.org/article/e0b27106b6414bf6925dd3d516f7fe75
Autor:
Chris Nagele, Hideyuki Umeda
Publikováno v:
The Astrophysical Journal Letters, Vol 949, Iss 1, p L16 (2023)
GN-z11 is an unusually luminous high-redshift galaxy that was recently observed to have strong nitrogen lines while at the same time lacking traditional signatures of active galactic nucleus activity. These observations have been interpreted as a sup
Externí odkaz:
https://doaj.org/article/470e0a79283b4530a6eff263362589d8
Autor:
Toshiki Sato, Takashi Yoshida, Hideyuki Umeda, John P. Hughes, Keiichi Maeda, Shigehiro Nagataki, Brian J. Williams
Publikováno v:
The Astrophysical Journal, Vol 954, Iss 2, p 112 (2023)
Neutrino interactions with stellar material are widely believed to be fundamental to the explosion of massive stars. However, this important process has remained difficult to confirm observationally. We propose a new method to verify it using X-ray o
Externí odkaz:
https://doaj.org/article/d851a475587c488d8427e9d6c0d7d07b
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:
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: Letters. 505:L69-L73
We perform a binary population synthesis calculation incorporating very massive population (Pop.) III stars up to 1500 $M_\odot$, and investigate the nature of binary black hole (BBH) mergers. Above the pair-instability mass gap, we find that the typ