Zobrazeno 1 - 10
of 95
pro vyhledávání: '"Kazumi Kashiyama"'
Autor:
Takatoshi Ko, Hiromasa Suzuki, Kazumi Kashiyama, Hiroyuki Uchida, Takaaki Tanaka, Daichi Tsuna, Kotaro Fujisawa, Aya Bamba, Toshikazu Shigeyama
Publikováno v:
The Astrophysical Journal, Vol 969, Iss 2, p 116 (2024)
IRAS 00500+6713 is a hypothesized remnant of a Type Iax supernova SN 1181. Multiwavelength observations have revealed its complicated morphology; a dusty infrared ring is sandwiched by the inner and outer X-ray nebulae. We analyze the archival X-ray
Externí odkaz:
https://doaj.org/article/5e49426f7b1d49d58fffbc876c1f5b0d
Publikováno v:
The Astrophysical Journal, Vol 966, Iss 2, p 164 (2024)
The James Webb Space Telescope (JWST) has recently uncovered the presence of low-luminosity active galactic nuclei (AGNs) at z = 4–11. Spectroscopic observations have provided estimates of the nuclear black hole (BH) masses for these sources, exten
Externí odkaz:
https://doaj.org/article/097b80a325564e9f81cf1c7e339e6b7a
Publikováno v:
The Astrophysical Journal, Vol 963, Iss 1, p 26 (2024)
We numerically construct a series of axisymmetric rotating magnetic wind solutions, aiming at exploring the observation properties of massive white dwarf (WD) merger remnants with a strong magnetic field, a fast spin, and an intense mass loss, as inf
Externí odkaz:
https://doaj.org/article/578b2045835e4283a7f08ac3b5a623de
Autor:
Mariko Kimura, Kazumi Kashiyama, Toshikazu Shigeyama, Yusuke Tampo, Shinya Yamada, Teruaki Enoto
Publikováno v:
The Astrophysical Journal, Vol 951, Iss 2, p 124 (2023)
We present timing and spectral analysis results of the NICER and NuSTAR observations of the dwarf nova MASTER OT J030227.28+191754.5 during the 2021–2022 outburst. The soft X-ray component was found to be dominated by blackbody radiation with a tem
Externí odkaz:
https://doaj.org/article/abacdc6767574f53a00dd155e72b09bd
Publikováno v:
Publications of the Astronomical Society of Japan. 75:103-119
We develop a general framework to compute photometric variations induced by the oblique rotation of a star with an axisymmetric inhomogeneous surface. We apply the framework to compute lightcurves of white dwarfs adopting two simple models of their s
Autor:
Masataka Aizawa, Kojiro Kawana, Kazumi Kashiyama, Ryou Ohsawa, Hajime Kawahara, Fumihiro Naokawa, Tomoyuki Tajiri, Noriaki Arima, Hanchun Jiang, Tilman Hartwig, Kotaro Fujisawa, Toshikazu Shigeyama, Ko Arimatsu, Mamoru Doi, Toshihiro Kasuga, Naoto Kobayashi, Sohei Kondo, Yuki Mori, Shin-ichiro Okumura, Satoshi Takita, Shigeyuki Sako
Publikováno v:
Publications of the Astronomical Society of Japan. 74:1069-1094
We report a one-second-cadence wide-field survey for M-dwarf flares using the Tomo-e Gozen camera mounted on the Kiso Schmidt telescope. We detect 22 flares from M3-M5 dwarfs with rise times and amplitudes ranging from $5\, \mathrm{sec} \lesssim t_\m
Publikováno v:
Monthly Notices of the Royal Astronomical Society. 513:6210-6218
Luminosity evolution of some stripped-envelope supernovae such as Type I superluminous supernovae is difficult to be explained by the canonical 56Ni nuclear decay heating. A popular alternative heating source is rapid spin down of strongly-magnetized
Autor:
Geoffrey C. Bower, Conor Omand, D. B. Fox, R. Margutti, Kohta Murase, Ryan Chornock, Hiroshi Nagai, Deanne L. Coppejans, Casey J. Law, Peter Mészáros, Kazumi Kashiyama
Publikováno v:
Monthly Notices of the Royal Astronomical Society. 508:44-51
Fast-rotating pulsars and magnetars have been suggested as the central engines of super-luminous supernovae (SLSNe) and fast radio bursts, and this scenario naturally predicts non-thermal synchrotron emission from their nascent pulsar wind nebulae (P
We consider fallback accretion after an ultra-stripped supernova (USSN) that accompanies formation of a binary neutron star (BNS) or a neutron star-black hole binary (NS-BH). The fallback matter initially accretes directly to the nascent NS, while it
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::c53cb8842590ad6a50de718b34ad9f28
http://arxiv.org/abs/2204.08851
http://arxiv.org/abs/2204.08851
Autor:
Kazumi Kashiyama, Naoki Seto
Publikováno v:
International Journal of Astrobiology. 19:308-313
We discuss the prospects of high precision pointing of our transmitter to habitable planets around Galactic main sequence stars. For an efficient signal delivery, the future sky positions of the host stars should be appropriately extrapolated with ac