The SOFIA Massive (SOMA) star formation Q-band follow-up

IF 5.8 2区 物理与天体物理 Q1 ASTRONOMY & ASTROPHYSICS
Prasanta Gorai, Kotomi Taniguchi, Jonathan C. Tan, Miguel Gómez-Garrido, Viviana Rosero, Izaskun Jiménez-Serra, Yichen Zhang, Giuliana Cosentino, Chi-Yan Law, Rubén Fedriani, Gemma Busquet, Brandt A. L. Gaches, Maryam Saberi, Ankan Das
{"title":"The SOFIA Massive (SOMA) star formation Q-band follow-up","authors":"Prasanta Gorai, Kotomi Taniguchi, Jonathan C. Tan, Miguel Gómez-Garrido, Viviana Rosero, Izaskun Jiménez-Serra, Yichen Zhang, Giuliana Cosentino, Chi-Yan Law, Rubén Fedriani, Gemma Busquet, Brandt A. L. Gaches, Maryam Saberi, Ankan Das","doi":"10.1051/0004-6361/202556220","DOIUrl":null,"url":null,"abstract":"<i>Context<i/>. Hydrogen recombination lines (HRLs) are valuable diagnostics of the physical conditions in ionized regions surrounding high-mass stars. Understanding these lines, including broadening mechanisms and intensity trends, can provide insights into HII region densities, temperatures, and kinematics.<i>Aims<i/>. This study aims to investigate the physical properties of ionized gas around massive protostars by analysing the HRLs (H<i>α<i/> and H<i>β<i/>) in the Q band.<i>Methods<i/>. We carried out observations using the Yebes 40m radio telescope in the Q band (30.5–50 GHz) towards six high-mass protostars selected from the SOMA Survey (G45.12+0.13, G45.47+0.05, G28.20−0.05, G35.20−0.74, G19.08−0.29, and G31.28+0.06). The observed line profiles were analysed to assess broadening mechanisms, and electron densities and temperatures were derived. The results were compared with available Q-band data from the TianMa 65-m Radio Telescope (TMRT) that have been reported in the literature, and ALMA Band 1 (35–50 GHz) Science Verification observations towards Orion KL, analysed in this study.<i>Results<i/>. A total of eight H<i>α<i/> (n = 51 to 58) and ten H<i>β<i/> (n = 64 to 73) lines were detected towards G45.12+0.13, G45.47+0.05, and G28.20−0.05; there were no detections in other sources. We derived electron densities of ~1−5 × 10<sup>6<sup/> cm<sup>−3<sup/> and temperatures of 8000–10 000 K for the sources. However, for Orion KL, we obtained an electron density one order of magnitude lower, while its temperature was found to be more similar. Interestingly, G45.12 and G28.20 show an increasing intensity trend with frequency for both H<i>α<i/> and H<i>β<i/> transitions, contrary to the decreasing trend observed in Orion KL.<i>Conclusions<i/>. The line widths of the detected HRLs indicate contributions from both thermal and dynamical broadening, suggesting the presence of high-temperature ionized gas that is likely kinematically broadened (e.g. due to turbulence, outflows, rapid rotation, or stellar winds). Pressure broadening caused by electron density may also have a minor effect. We discuss different scenarios to explain the measured line widths of the HRLs. The contrasting intensity trends between the sources may reflect variations in local physical conditions or radiative transfer effects, highlighting the need for further investigation through higher-resolution observations and detailed modelling.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"86 1","pages":""},"PeriodicalIF":5.8000,"publicationDate":"2025-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Astronomy & Astrophysics","FirstCategoryId":"101","ListUrlMain":"https://doi.org/10.1051/0004-6361/202556220","RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ASTRONOMY & ASTROPHYSICS","Score":null,"Total":0}
引用次数: 0

Abstract

Context. Hydrogen recombination lines (HRLs) are valuable diagnostics of the physical conditions in ionized regions surrounding high-mass stars. Understanding these lines, including broadening mechanisms and intensity trends, can provide insights into HII region densities, temperatures, and kinematics.Aims. This study aims to investigate the physical properties of ionized gas around massive protostars by analysing the HRLs (Hα and Hβ) in the Q band.Methods. We carried out observations using the Yebes 40m radio telescope in the Q band (30.5–50 GHz) towards six high-mass protostars selected from the SOMA Survey (G45.12+0.13, G45.47+0.05, G28.20−0.05, G35.20−0.74, G19.08−0.29, and G31.28+0.06). The observed line profiles were analysed to assess broadening mechanisms, and electron densities and temperatures were derived. The results were compared with available Q-band data from the TianMa 65-m Radio Telescope (TMRT) that have been reported in the literature, and ALMA Band 1 (35–50 GHz) Science Verification observations towards Orion KL, analysed in this study.Results. A total of eight Hα (n = 51 to 58) and ten Hβ (n = 64 to 73) lines were detected towards G45.12+0.13, G45.47+0.05, and G28.20−0.05; there were no detections in other sources. We derived electron densities of ~1−5 × 106 cm−3 and temperatures of 8000–10 000 K for the sources. However, for Orion KL, we obtained an electron density one order of magnitude lower, while its temperature was found to be more similar. Interestingly, G45.12 and G28.20 show an increasing intensity trend with frequency for both Hα and Hβ transitions, contrary to the decreasing trend observed in Orion KL.Conclusions. The line widths of the detected HRLs indicate contributions from both thermal and dynamical broadening, suggesting the presence of high-temperature ionized gas that is likely kinematically broadened (e.g. due to turbulence, outflows, rapid rotation, or stellar winds). Pressure broadening caused by electron density may also have a minor effect. We discuss different scenarios to explain the measured line widths of the HRLs. The contrasting intensity trends between the sources may reflect variations in local physical conditions or radiative transfer effects, highlighting the need for further investigation through higher-resolution observations and detailed modelling.
索非亚大质量(SOMA)恒星形成q波段追踪
上下文。氢复合谱线(HRLs)对大质量恒星周围电离区域的物理状况具有重要的诊断价值。了解这些线条,包括扩展机制和强度趋势,可以深入了解HII区域的密度、温度和运动学。本研究旨在通过分析Q波段的HRLs (Hα和Hβ)来研究大质量原恒星周围电离气体的物理性质。我们利用Yebes 40m射电望远镜在Q波段(30.5-50 GHz)对从SOMA巡天中选择的6颗高质量原恒星(G45.12+0.13, G45.47+0.05, G28.20−0.05,G35.20−0.74,G19.08−0.29和G31.28+0.06)进行了观测。对观察到的谱线进行了分析,以评估增宽机制,并推导出电子密度和温度。结果与已有文献报道的天马65米射电望远镜(TMRT)的可用q波段数据进行了比较,并对ALMA波段1 (35-50 GHz)对猎户座KL的科学验证观测结果进行了分析。在G45.12+0.13、G45.47+0.05和G28.20−0.05方向共检测到8株Hα (n = 51 ~ 58)和10株Hβ (n = 64 ~ 73);在其他来源中没有检测到。我们推导出源的电子密度为~1−5 × 106 cm−3,温度为8000-10 000 K。然而,对于猎户座KL,我们得到了一个低一个数量级的电子密度,而它的温度被发现更相似。有趣的是,G45.12和G28.20的Hα和Hβ跃迁强度随频率的增加而增加,与猎户座l相反。探测到的HRLs的线宽表明了热展宽和动力展宽的贡献,表明高温电离气体的存在可能是运动展宽的(例如,由于湍流、流出、快速旋转或恒星风)。由电子密度引起的压力展宽也可能有轻微的影响。我们讨论了不同的场景来解释测量的hrl线宽。不同辐射源之间的强度变化趋势可能反映了当地物理条件或辐射转移效应的变化,因此需要通过更高分辨率的观测和详细的模拟进行进一步研究。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
求助全文
约1分钟内获得全文 求助全文
来源期刊
Astronomy & Astrophysics
Astronomy & Astrophysics 地学天文-天文与天体物理
CiteScore
10.20
自引率
27.70%
发文量
2105
审稿时长
1-2 weeks
期刊介绍: Astronomy & Astrophysics is an international Journal that publishes papers on all aspects of astronomy and astrophysics (theoretical, observational, and instrumental) independently of the techniques used to obtain the results.
×
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
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:604180095
Book学术官方微信