Stellar feedback on the earliest stage of massive star formation
We report SOFIA/GREAT observations of high-J CO lines and [C ii] observations of the super star cluster candidate H72.97-69.39 in the Large Magellanic Cloud (LMC), which is in its very early formation stage. We use our observations to determine if shocks are heating the gas or if photon-dominated re...
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| Hauptverfasser: | , |
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| Dokumenttyp: | Article (Journal) |
| Sprache: | Englisch |
| Veröffentlicht: |
2021 February 3
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| In: |
The astrophysical journal
Year: 2021, Jahrgang: 907, Heft: 2, Pages: 1-12 |
| ISSN: | 1538-4357 |
| DOI: | 10.3847/1538-4357/abcb89 |
| Online-Zugang: | Verlag, lizenzpflichtig, Volltext: https://doi.org/10.3847/1538-4357/abcb89
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| Verfasserangaben: | O. Nayak, M. Meixner, Y. Okada, M.Y. Lee, M. Chevance, C. Buchbender, Y. Fukui, T. Onishi, A. Parikka, and J. Stutzki |
| Zusammenfassung: | We report SOFIA/GREAT observations of high-J CO lines and [C ii] observations of the super star cluster candidate H72.97-69.39 in the Large Magellanic Cloud (LMC), which is in its very early formation stage. We use our observations to determine if shocks are heating the gas or if photon-dominated regions (PDRs) are being heated by local far-UV radiation. We use a PDR model and a shock model to determine whether the CO and [C ii] lines arise from PDRs or shocks. We can reproduce the observed high-J CO and [C ii] emission with a clumpy PDR model with the following properties: a density of 104.7 cm−3, a mass of 104 M⊙, and UV radiation of 103.5 in units of Draine field. Comparison with the ALMA beam-filling factor suggests a higher density within the uncertainty of the fit. We find the lower-limit [C ii]/total infrared (TIR) ratio (ϵ) traced by [C ii]/TIR to be 0.026%, lower than other known young star-forming regions in the LMC. Our shock models may explain the CO (16−15) and CO (11−10) emission lines with shock velocity of 8-11 km s−1, pre-shock density of 104-105 cm−3, and GUV = 0 in units of Draine field. However, the [C ii] line emission cannot be explained by a shock model, thus it is originating in a different gas component. Observations of [O i] 63 μm predicted to be 1.1 × 10−13 W m−2 by PDR models and 7.8 × 10−15 W m−2 by shock models will help distinguish between the PDR and shock scenarios. |
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| Beschreibung: | Gesehen am 26.11.2021 |
| Beschreibung: | Online Resource |
| ISSN: | 1538-4357 |
| DOI: | 10.3847/1538-4357/abcb89 |