Study of Maser Emission in 18 cm Lines in the Star Formation Region G 109.871+2.114 (Cep A)

IF 1.1 4区 物理与天体物理 Q3 ASTRONOMY & ASTROPHYSICS
E. E. Lekht, N. T. Ashimbaeva, V. V. Krasnov, V. R. Shutenkov
{"title":"Study of Maser Emission in 18 cm Lines in the Star Formation Region G 109.871+2.114 (Cep A)","authors":"E. E. Lekht,&nbsp;N. T. Ashimbaeva,&nbsp;V. V. Krasnov,&nbsp;V. R. Shutenkov","doi":"10.1134/S106377292470080X","DOIUrl":null,"url":null,"abstract":"<p>The results of the study of the star formation region G 109.871+2.114 (Cep A) in OH lines at 18 cm are presented. Polarization observations (monitoring) were performed with a large Nançay radio telescope (France) in 2007–2024. OH maser emission is highly variable. The structure of the spectrum and the flux density of the individual spectral features are changing. However, the radial velocities of most features changed slightly. Short-term emission flares in individual features were observed. Many features have strong circular polarization, reaching 100%, but have weak linear polarization. A new features at –15.53 km/s and a short-term part at 1.58 km/s with high circular and low linear polarizations were detected in the 1667 MHz line. The spectral features of our monitoring were spatially identified with the maser spots on the Cohen, Argon, and Fish maps. The magnitude of the monotonic decrease in splitting, and, consequently, the longitudinal magnetic field of three Zeeman pairs (–16.2<i>L</i>/–14.25<i>R</i> and –6.94<i>L</i>/–0.82<i>R</i> km/s in the 1665 MHz line and –15.76<i>L</i>/–14.2<i>R</i> in the 1667 MHz line). For the –13.95<i>L</i>/–11.60<i>R</i> pair, no splitting change was detected in the 1665 MHz line. Broadband absorption and emission are observed in the satellite lines of 1612 and 1720 MHz, respectively. A Zeeman pair was also detected in the 1720 MHz line. The position angle <span>\\(\\chi \\)</span> is calculated for linearly polarized emission of most spectral features in both main lines at 1665 and 1667 MHz. It is shown that the magnetic field in the H II regions is oriented either along the external magnetic field or along the radio jets.</p>","PeriodicalId":55440,"journal":{"name":"Astronomy Reports","volume":"68 9","pages":"906 - 924"},"PeriodicalIF":1.1000,"publicationDate":"2024-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Astronomy Reports","FirstCategoryId":"101","ListUrlMain":"https://link.springer.com/article/10.1134/S106377292470080X","RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"ASTRONOMY & ASTROPHYSICS","Score":null,"Total":0}
引用次数: 0

Abstract

The results of the study of the star formation region G 109.871+2.114 (Cep A) in OH lines at 18 cm are presented. Polarization observations (monitoring) were performed with a large Nançay radio telescope (France) in 2007–2024. OH maser emission is highly variable. The structure of the spectrum and the flux density of the individual spectral features are changing. However, the radial velocities of most features changed slightly. Short-term emission flares in individual features were observed. Many features have strong circular polarization, reaching 100%, but have weak linear polarization. A new features at –15.53 km/s and a short-term part at 1.58 km/s with high circular and low linear polarizations were detected in the 1667 MHz line. The spectral features of our monitoring were spatially identified with the maser spots on the Cohen, Argon, and Fish maps. The magnitude of the monotonic decrease in splitting, and, consequently, the longitudinal magnetic field of three Zeeman pairs (–16.2L/–14.25R and –6.94L/–0.82R km/s in the 1665 MHz line and –15.76L/–14.2R in the 1667 MHz line). For the –13.95L/–11.60R pair, no splitting change was detected in the 1665 MHz line. Broadband absorption and emission are observed in the satellite lines of 1612 and 1720 MHz, respectively. A Zeeman pair was also detected in the 1720 MHz line. The position angle \(\chi \) is calculated for linearly polarized emission of most spectral features in both main lines at 1665 and 1667 MHz. It is shown that the magnetic field in the H II regions is oriented either along the external magnetic field or along the radio jets.

Abstract Image

求助全文
约1分钟内获得全文 求助全文
来源期刊
Astronomy Reports
Astronomy Reports 地学天文-天文与天体物理
CiteScore
1.40
自引率
20.00%
发文量
57
审稿时长
6-12 weeks
期刊介绍: Astronomy Reports is an international peer reviewed journal that publishes original papers on astronomical topics, including theoretical and observational astrophysics, physics of the Sun, planetary astrophysics, radio astronomy, stellar astronomy, celestial mechanics, and astronomy methods and instrumentation.
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
copy
已复制链接
快去分享给好友吧!
我知道了
右上角分享
点击右上角分享
0
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术官方微信