View in EDS

The SOFIA Massive (SOMA) star formation Q-band follow-up II. Hydrogen recombination lines towards high-mass protostars

Saved in:
Bibliographic Details
Title: The SOFIA Massive (SOMA) star formation Q-band follow-up II. Hydrogen recombination lines towards high-mass protostars
Authors: Gorai, Prasanta, Taniguchi, Kotomi, Tan, Jonathan, 1973, Gomez-Garrido, Miguel, Rosero, Viviana, Jimenez-Serra, Izaskun, Zhang, Yichen, Cosentino, Giuliana, Law, Chi-Yan, Fedriani, Ruben, Busquet, Gemma, Gaches, Brandt A. L., Saberi, Maryam, Das, Ankan
Source: Astronomy and Astrophysics. 702
Subject Terms: stars: massive, line: identification, line: profiles, methods: data analysis, HII regions, astrochemistry
Description: 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 (H alpha and H beta) 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 H alpha (n = 51 to 58) and ten H beta (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 similar to 1-5 x 10(6) 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 H alpha and H beta 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.
File Description: electronic
Access URL: https://research.chalmers.se/publication/548806
https://research.chalmers.se/publication/548806/file/548806_Fulltext.pdf
Database: SwePub
FullText Text:
  Availability: 0
CustomLinks:
  – Url: https://research.chalmers.se/publication/548806#
    Name: EDS - SwePub (s4221598)
    Category: fullText
    Text: View record in SwePub
  – Url: https://resolver.ebscohost.com/openurl?sid=EBSCO:edsswe&genre=article&issn=00046361&ISBN=&volume=702&issue=&date=20250101&spage=&pages=&title=Astronomy and Astrophysics&atitle=The%20SOFIA%20Massive%20%28SOMA%29%20star%20formation%20Q-band%20follow-up%20II.%20Hydrogen%20recombination%20lines%20towards%20high-mass%20protostars&aulast=Gorai%2C%20Prasanta&id=DOI:10.1051/0004-6361/202556220
    Name: Full Text Finder
    Category: fullText
    Text: Full Text Finder
    Icon: https://imageserver.ebscohost.com/branding/images/FTF.gif
    MouseOverText: Full Text Finder
  – Url: https://www.webofscience.com/api/gateway?GWVersion=2&SrcApp=EBSCO&SrcAuth=EBSCO&DestApp=WOS&ServiceName=TransferToWoS&DestLinkType=GeneralSearchSummary&Func=Links&author=Gorai%20P
    Name: ISI
    Category: fullText
    Text: Nájsť tento článok vo Web of Science
    Icon: https://imagesrvr.epnet.com/ls/20docs.gif
    MouseOverText: Nájsť tento článok vo Web of Science
Header DbId: edsswe
DbLabel: SwePub
An: edsswe.oai.research.chalmers.se.01a94c3f.1e34.4ba1.a452.0e3d0f303a1b
RelevancyScore: 1065
AccessLevel: 6
PubType: Academic Journal
PubTypeId: academicJournal
PreciseRelevancyScore: 1064.736328125
IllustrationInfo
Items – Name: Title
  Label: Title
  Group: Ti
  Data: The SOFIA Massive (SOMA) star formation Q-band follow-up II. Hydrogen recombination lines towards high-mass protostars
– Name: Author
  Label: Authors
  Group: Au
  Data: <searchLink fieldCode="AR" term="%22Gorai%2C+Prasanta%22">Gorai, Prasanta</searchLink><br /><searchLink fieldCode="AR" term="%22Taniguchi%2C+Kotomi%22">Taniguchi, Kotomi</searchLink><br /><searchLink fieldCode="AR" term="%22Tan%2C+Jonathan%22">Tan, Jonathan</searchLink>, 1973<br /><searchLink fieldCode="AR" term="%22Gomez-Garrido%2C+Miguel%22">Gomez-Garrido, Miguel</searchLink><br /><searchLink fieldCode="AR" term="%22Rosero%2C+Viviana%22">Rosero, Viviana</searchLink><br /><searchLink fieldCode="AR" term="%22Jimenez-Serra%2C+Izaskun%22">Jimenez-Serra, Izaskun</searchLink><br /><searchLink fieldCode="AR" term="%22Zhang%2C+Yichen%22">Zhang, Yichen</searchLink><br /><searchLink fieldCode="AR" term="%22Cosentino%2C+Giuliana%22">Cosentino, Giuliana</searchLink><br /><searchLink fieldCode="AR" term="%22Law%2C+Chi-Yan%22">Law, Chi-Yan</searchLink><br /><searchLink fieldCode="AR" term="%22Fedriani%2C+Ruben%22">Fedriani, Ruben</searchLink><br /><searchLink fieldCode="AR" term="%22Busquet%2C+Gemma%22">Busquet, Gemma</searchLink><br /><searchLink fieldCode="AR" term="%22Gaches%2C+Brandt+A%2E+L%2E%22">Gaches, Brandt A. L.</searchLink><br /><searchLink fieldCode="AR" term="%22Saberi%2C+Maryam%22">Saberi, Maryam</searchLink><br /><searchLink fieldCode="AR" term="%22Das%2C+Ankan%22">Das, Ankan</searchLink>
– Name: TitleSource
  Label: Source
  Group: Src
  Data: <i>Astronomy and Astrophysics</i>. 702
– Name: Subject
  Label: Subject Terms
  Group: Su
  Data: <searchLink fieldCode="DE" term="%22stars%3A+massive%22">stars: massive</searchLink><br /><searchLink fieldCode="DE" term="%22line%3A+identification%22">line: identification</searchLink><br /><searchLink fieldCode="DE" term="%22line%3A+profiles%22">line: profiles</searchLink><br /><searchLink fieldCode="DE" term="%22methods%3A+data+analysis%22">methods: data analysis</searchLink><br /><searchLink fieldCode="DE" term="%22HII+regions%22">HII regions</searchLink><br /><searchLink fieldCode="DE" term="%22astrochemistry%22">astrochemistry</searchLink>
– Name: Abstract
  Label: Description
  Group: Ab
  Data: 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 (H alpha and H beta) 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 H alpha (n = 51 to 58) and ten H beta (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 similar to 1-5 x 10(6) 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 H alpha and H beta 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.
– Name: Format
  Label: File Description
  Group: SrcInfo
  Data: electronic
– Name: URL
  Label: Access URL
  Group: URL
  Data: <link linkTarget="URL" linkTerm="https://research.chalmers.se/publication/548806" linkWindow="_blank">https://research.chalmers.se/publication/548806</link><br /><link linkTarget="URL" linkTerm="https://research.chalmers.se/publication/548806/file/548806_Fulltext.pdf" linkWindow="_blank">https://research.chalmers.se/publication/548806/file/548806_Fulltext.pdf</link>
PLink https://erproxy.cvtisr.sk/sfx/access?url=https://search.ebscohost.com/login.aspx?direct=true&site=eds-live&db=edsswe&AN=edsswe.oai.research.chalmers.se.01a94c3f.1e34.4ba1.a452.0e3d0f303a1b
RecordInfo BibRecord:
  BibEntity:
    Identifiers:
      – Type: doi
        Value: 10.1051/0004-6361/202556220
    Languages:
      – Text: English
    Subjects:
      – SubjectFull: stars: massive
        Type: general
      – SubjectFull: line: identification
        Type: general
      – SubjectFull: line: profiles
        Type: general
      – SubjectFull: methods: data analysis
        Type: general
      – SubjectFull: HII regions
        Type: general
      – SubjectFull: astrochemistry
        Type: general
    Titles:
      – TitleFull: The SOFIA Massive (SOMA) star formation Q-band follow-up II. Hydrogen recombination lines towards high-mass protostars
        Type: main
  BibRelationships:
    HasContributorRelationships:
      – PersonEntity:
          Name:
            NameFull: Gorai, Prasanta
      – PersonEntity:
          Name:
            NameFull: Taniguchi, Kotomi
      – PersonEntity:
          Name:
            NameFull: Tan, Jonathan
      – PersonEntity:
          Name:
            NameFull: Gomez-Garrido, Miguel
      – PersonEntity:
          Name:
            NameFull: Rosero, Viviana
      – PersonEntity:
          Name:
            NameFull: Jimenez-Serra, Izaskun
      – PersonEntity:
          Name:
            NameFull: Zhang, Yichen
      – PersonEntity:
          Name:
            NameFull: Cosentino, Giuliana
      – PersonEntity:
          Name:
            NameFull: Law, Chi-Yan
      – PersonEntity:
          Name:
            NameFull: Fedriani, Ruben
      – PersonEntity:
          Name:
            NameFull: Busquet, Gemma
      – PersonEntity:
          Name:
            NameFull: Gaches, Brandt A. L.
      – PersonEntity:
          Name:
            NameFull: Saberi, Maryam
      – PersonEntity:
          Name:
            NameFull: Das, Ankan
    IsPartOfRelationships:
      – BibEntity:
          Dates:
            – D: 01
              M: 01
              Type: published
              Y: 2025
          Identifiers:
            – Type: issn-print
              Value: 00046361
            – Type: issn-print
              Value: 14320746
            – Type: issn-locals
              Value: SWEPUB_FREE
            – Type: issn-locals
              Value: CTH_SWEPUB
          Numbering:
            – Type: volume
              Value: 702
          Titles:
            – TitleFull: Astronomy and Astrophysics
              Type: main
ResultId 1