Zobrazeno 1 - 10
of 316
pro vyhledávání: '"Hamaguchi, Kenji"'
High-velocity blue-shifted Fe XXV He$\alpha$ line during a superflare of the RS CVn-type star IM Peg
Autor:
Inoue, Shun, Iwakiri, Wataru Buz, Enoto, Teruaki, Uchida, Hiroyuki, Kurihara, Miki, Tsujimoto, Masahiro, Notsu, Yuta, Hamaguchi, Kenji, Gendreau, Keith, Arzoumanian, Zaven, Tsuru, Takeshi Go
Monitor of All-sky X-ray Image (MAXI) detected a superflare, releasing $5\times 10^{37}$ erg in 2$-$10 keV, of the RS CVn-type star IM Peg at 10:41 UT on 2023 July 23 with its Gas Slit Camera (GSC; 2$-$30 keV). We conducted X-ray follow-up observatio
Externí odkaz:
http://arxiv.org/abs/2406.06940
Autor:
Oka, Tomohiko, Ogio, Shingo, Abe, Mitsuru, Hamaguchi, Kenji, Ikeda, Tomonori, Kubo, Hidetoshi, Kurosawa, Shunsuke, Miuchi, Kentaro, Mizumura, Yoshitaka, Nakamura, Yuta, Sawano, Tatsuya, Takada, Atsushi, Takemura, Taito, Tanimori, Toru, Yoshikawa, Kei
Although the MeV gamma-ray band is a promising energy-band window in astrophysics, the current situation of MeV gamma-ray astronomy significantly lags behind those of the other energy bands in angular resolution and sensitivity. An electron-tracking
Externí odkaz:
http://arxiv.org/abs/2403.05128
Autor:
Miyamoto, Asca, Sugawara, Yasuharu, Maeda, Yoshitomo, Ishida, Manabu, Hamaguchi, Kenji, Russell, Christopher M. P., Moffat, Anthony F. J.
We analyse $\textit{XMM-Newton}$ RGS spectra of Wolf-Rayet (WR) 140, an archetype long-period eccentric WR+O colliding wind binary. We evaluate the spectra of O and Fe emission lines and find that the plasmas emitting these lines have the largest app
Externí odkaz:
http://arxiv.org/abs/2401.00977
Autor:
Notsu, Yuta, Kowalski, Adam F., Maehara, Hiroyuki, Namekata, Kosuke, Hamaguchi, Kenji, Enoto, Teruaki, Tristan, Isaiah I., Hawley, Suzanne L., Davenport, James R. A., Honda, Satoshi, Ikuta, Kai, Inoue, Shun, Namizaki, Keiichi, Nogami, Daisaku, Shibata, Kazunari
We conducted the time-resolved simultaneous optical spectroscopic and photometric observations of mid M dwarf flare stars YZ CMi, EV Lac, and AD Leo. Spectroscopic observations were obtained using Apache Point Observatory 3.5m and Small \& Moderate A
Externí odkaz:
http://arxiv.org/abs/2310.02450
Autor:
Gull, Theodore R., Hartman, Henrik, Teodoro, Mairan, Hillier, D. John, Corcoran, Michael F., Damineli, Augusto, Hamaguchi, Kenji, Madura, Thomas, Moffat, Anthony F. J., Morris, Patrick, Richardson, Noel D., Stevens, Ian R., Weigelt, Gerd
Previous STIS long-slit observations of Eta Carinae identified numerous absorption features in both the stellar spectrum, and in the adjacent nebular spectra, along our line-of-sight. The absorption features became temporarily stronger when the ioniz
Externí odkaz:
http://arxiv.org/abs/2305.13216
Autor:
Hamaguchi, Kenji, Reep, Jeffrey W., Airapetian, Vladimir, Toriumi, Shin, Gendreau, Keith C., Arzoumanian, Zaven
The Neutron star Interior Composition ExploreR (NICER) X-ray observatory observed two powerful X-ray flares equivalent to superflares from the nearby young solar-like star, kappa1 Ceti, in 2019. NICER follows each flare from the onset through the ear
Externí odkaz:
http://arxiv.org/abs/2301.01377
Autor:
Lau, Ryan M., Hankins, Matthew J., Han, Yinuo, Argyriou, Ioannis, Corcoran, Michael F., Eldridge, Jan J., Endo, Izumi, Fox, Ori D., Marin, Macarena Garcia, Gull, Theodore R., Jones, Olivia C., Hamaguchi, Kenji, Lamberts, Astrid, Law, David R., Madura, Thomas, Marchenko, Sergey V., Matsuhara, Hideo, Moffat, Anthony F. J., Morris, Mark R., Morris, Patrick W., Onaka, Takashi, Ressler, Michael E., Richardson, Noel D., Russell, Christopher M. P., Sanchez-Bermudez, Joel, Smith, Nathan, Soulain, Anthony, Stevens, Ian R., Tuthill, Peter, Weigelt, Gerd, Williams, Peredur M., Yamaguchi, Ryodai
Publikováno v:
Lau, R.M., Hankins, M.J., Han, Y. et al. Nested dust shells around the Wolf-Rayet binary WR 140 observed with JWST. Nat Astron (2022)
Massive colliding-wind binaries that host a Wolf-Rayet (WR) star present a potentially important source of dust and chemical enrichment in the interstellar medium (ISM). However, the chemical composition and survival of dust formed from such systems
Externí odkaz:
http://arxiv.org/abs/2210.06452
Autor:
Espinoza-Galeas, David, Corcoran, Michael Francis, Hamaguchi, Kenji, Russell, Christopher M. P., Gull, Theodore R., Moffat, Anthony, Richardson, Noel D., Weigelt, Gerd, Hillier, D. John, Damineli, Augusto, Stevens, Ian R., Madura, Thomas, Gendreau, Keith, Arzoumanian, Zaven, Navarete, Felipe
We report high-precision X-ray monitoring observations in the 0.4-10 keV band of the luminous, long-period colliding-wind binary Eta Carinae up to and through its most recent X-ray minimum/periastron passage in February 2020. Eta Carinae reached its
Externí odkaz:
http://arxiv.org/abs/2207.03457
Eta Carinae: an evolving view of the central binary, its interacting winds and its foreground ejecta
Autor:
Gull, Theodore R., Hillier, D. John, Hartman, Henrik, Corcoran, Michael F., Damineli, Augusto, Espinoza-Galeas, David, Hamaguchi, Kenji, Navarete, Felipe, Nielsen, Krister, Madura, Thomas, Moffat, Anthony F. J., Morris, Patrick, Richardson, Noel D., Russell, Christopher M. P., Stevens, Ian R., Weigelt, Gerd
FUV spectra of Eta Car, recorded across two decades with HST/STIS, document multiple changes in resonant lines caused by dissipating extinction in our line of sight. The FUV flux has increased nearly ten-fold which has led to increased ionization of
Externí odkaz:
http://arxiv.org/abs/2205.15116
Autor:
Paudel, Rishi R., Barclay, Thomas, Schlieder, Joshua E., Quintana, Elisa V., Gilbert, Emily A., Vega, Laura D., Youngblood, Allison, Silverstein, Michele, Osten, Rachel A., Tucker, Michael A., Huber, Daniel, Do, Aaron, Hamaguchi, Kenji, Mullan, D. J., Gizis, John E., Monsue, Teresa A., Colón, Knicole D., Boyd, Patricia T., Davenport, James R. A., Walkowicz, Lucianne
We present the first results of our ongoing project conducting simultaneous multiwavelength observations of flares on nearby active M dwarfs. We acquired data of the nearby dM3.5e star EV Lac using 5 different observatories: NASA's Transiting Exoplan
Externí odkaz:
http://arxiv.org/abs/2108.04753