Zobrazeno 1 - 10
of 100
pro vyhledávání: '"Jun-ichi NAKASHIMA"'
Publikováno v:
The Astrophysical Journal Letters, Vol 964, Iss 2, p L18 (2024)
Water fountain objects are generally defined as evolved stars with low to intermediate initial mass accompanied by high-velocity molecular jets detectable in the 22.235 GHz H _2 O maser line. They are the key objects of understanding the morphologica
Externí odkaz:
https://doaj.org/article/6ce226fdd2af44ae930c189567364208
Autor:
Xu-Jia Ouyang, Yong Zhang, Chuan-Peng Zhang, Peng Jiang, Jun-ichi Nakashima, Xi Chen, Hai-Hua Qiao, Xu-Ying Zhang, Hao-Min Sun, Xiao-Hu Li, Albert Zijlstra
Publikováno v:
The Astrophysical Journal, Vol 972, Iss 1, p 96 (2024)
We present the first detection of the ground-state OH emission line at 1612 MHz toward the prototypical carbon-rich planetary nebula (PN) NGC 7027, utilizing the newly installed ultrawideband (UWB) receiver of the Five-hundred-meter Aperture Spherica
Externí odkaz:
https://doaj.org/article/f21fbb82bced492cba8f9be9e0d4ac6c
Autor:
Jian-Jie Qiu, Yong Zhang, Jun-ichi Nakashima, Jiang-Shui Zhang, Fei Li, Deng-Rong Lu, Xin-Di Tang, Xiao-Ling Yu, Lan-Wei Jia
Publikováno v:
The Astronomical Journal, Vol 167, Iss 3, p 91 (2024)
It has been more than 30 years since the enigmatic 21 μ m emission feature was first discovered in protoplanetary nebulae (PPNs). Although dozens of different dust carrier candidates have been proposed, there is as yet no widely accepted one. We pre
Externí odkaz:
https://doaj.org/article/decb48271722405489a5970fc0991c7b
Autor:
Haichen Fan, Jun-ichi Nakashima, D. Engels, Yong Zhang, Jian-Jie Qiu, Huan-Xue Feng, Jia-Yong Xie, Hiroshi Imai, Chih-Hao Hsia
Publikováno v:
The Astrophysical Journal Supplement Series, Vol 270, Iss 1, p 13 (2024)
Water fountains (WFs) are thought to be objects in the morphological evolution of the circumstellar envelopes of low- and intermediate-mass evolved stars, transitioning from spherically symmetric to asymmetric shapes. We used databases of circumstell
Externí odkaz:
https://doaj.org/article/342f7e8ec15a45e8944f6b12f1bae907
Autor:
Xu-Jia Ouyang, Yong Zhang, Albert Zijlstra, Chuan-Peng Zhang, Jun-ichi Nakashima, Quentin A. Parker
Publikováno v:
The Astrophysical Journal, Vol 952, Iss 2, p 166 (2023)
The young, compact, very high surface brightness but low excitation planetary nebula (PN) BD+30°3639 is one of the very few PNe that have been reported to exhibit the 21 cm H i emission line. As part of a long-term program to search for circumstella
Externí odkaz:
https://doaj.org/article/607a621d232843d1ac4c1776b86a24da
Autor:
Jian-Jie Qiu, Yong Zhang, Jun-ichi Nakashima, Jiang-Shui Zhang, Nico Koning, Xin-Di Tang, Yao-Ting Yan, Huan-Xue Feng
Context. IRAS 19312+1950 is an isolated infrared source that exhibits a characteristic quasi-point-symmetric morphology in the near- and mid-infrared images and is also very bright in molecular radio lines. Because of its unique observational charact
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::493a41061434f57d019324d2fcdd3523
http://arxiv.org/abs/2211.13640
http://arxiv.org/abs/2211.13640
Autor:
Xu-Jia Ouyang, Yong Zhang, Albert Zijlstra, Chuan-Peng Zhang, Jun-ichi Nakashima, Quentin A Parker
Using the Five-hundred-meter Aperture Spherical radio Telescope (FAST) in Guizhou, China, we detect the 21cm neutral atomic hydrogen absorption in the young planetary nebula IC 4997. The absorption arises from a shell also associated with Na I D line
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::7ab654e8e741873ca549c96f35958ec6
http://arxiv.org/abs/2205.06170
http://arxiv.org/abs/2205.06170
Autor:
Shuangjing Xu, Hiroshi Imai, Youngjoo Yun, Bo Zhang, María J. Rioja, Richard Dodson, Se-Hyung Cho, Jaeheon Kim, Lang Cui, Andrey M. Sobolev, James O. Chibueze, Dong-Jin Kim, Kei Amada, Jun-ichi Nakashima, Gabor Orosz, Miyako Oyadomari, Sejin Oh, Yoshinori Yonekura, Yan Sun, Xiaofeng Mai, Jingdong Zhang, Shiming Wen, Taehyun Jung
Publikováno v:
The Astrophysical Journal. 941:105
We report VLBI monitoring observations of the 22 GHz water (H$_{2}$O) masers around the Mira variable BX Cam, which were carried out as a part of the EAVN Synthesis of Stellar Maser Animations (ESTEMA) project. Data of 37 epochs in total were obtaine
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::c6e6af9a0afcca2be27c65ae15733783
https://doi.org/10.3847/1538-4357/ac9599
https://doi.org/10.3847/1538-4357/ac9599
Autor:
Hiroshi Imai, Jun-ichi Nakashima, Daniel Tafoya, Gabor Orosz, Bosco H. K. Yung, José F. Gómez
Publikováno v:
Digital.CSIC. Repositorio Institucional del CSIC
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One of the major puzzles in the study of stellar evolution is the formation process of bipolar and multipolar planetary nebulae. There is growing consensus that collimated jets create cavities with dense walls in the slowly expanding (10-20 km s-1) e
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::fe8cecd0a0532f0be2b605f39887c084
http://arxiv.org/abs/2006.07157
http://arxiv.org/abs/2006.07157
Publikováno v:
Publications of the Astronomical Society of Japan. 72
We report an unbiased radio line survey towards the circumstellar envelopes of evolved stars at the frequency range from 20 to 25 GHz, aiming to obtain a more complete unbiased picture of the chemical evolution in the final stages of stellar evolutio
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::729e0748d56d1f8a99c3b5e18a65e9a5
https://doi.org/10.1093/pasj/psaa032
https://doi.org/10.1093/pasj/psaa032