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Luisi M, Anderson LD, Schneider N, Simon R, Kabanovic S, Güsten R, Zavagno A, Broos PS, Buchbender C, Guevara C, Jacobs K, Justen M, Klein B, Linville D, Röllig M, Russeil D, Stutzki J, Tiwari M, Townsley LK, Tielens AGGM. Stellar feedback and triggered star formation in the prototypical bubble RCW 120. SCIENCE ADVANCES 2021; 7:7/15/eabe9511. [PMID: 33837081 PMCID: PMC8034851 DOI: 10.1126/sciadv.abe9511] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 02/19/2021] [Indexed: 06/12/2023]
Abstract
Radiative and mechanical feedback of massive stars regulates star formation and galaxy evolution. Positive feedback triggers the creation of new stars by collecting dense shells of gas, while negative feedback disrupts star formation by shredding molecular clouds. Although key to understanding star formation, their relative importance is unknown. Here, we report velocity-resolved observations from the SOFIA (Stratospheric Observatory for Infrared Astronomy) legacy program FEEDBACK of the massive star-forming region RCW 120 in the [CII] 1.9-THz fine-structure line, revealing a gas shell expanding at 15 km/s. Complementary APEX (Atacama Pathfinder Experiment) CO J = 3-2 345-GHz observations exhibit a ring structure of molecular gas, fragmented into clumps that are actively forming stars. Our observations demonstrate that triggered star formation can occur on much shorter time scales than hitherto thought (<0.15 million years), suggesting that positive feedback operates on short time periods.
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Affiliation(s)
- Matteo Luisi
- Department of Physics and Astronomy, West Virginia University, Morgantown, WV 26506, USA.
- Center for Gravitational Waves and Cosmology, West Virginia University, Chestnut Ridge Research Building, Morgantown, WV 26505, USA
| | - Loren D Anderson
- Department of Physics and Astronomy, West Virginia University, Morgantown, WV 26506, USA
- Center for Gravitational Waves and Cosmology, West Virginia University, Chestnut Ridge Research Building, Morgantown, WV 26505, USA
- Adjunct Astronomer at the Green Bank Observatory, P.O. Box 2, Green Bank, WV 24944, USA
| | - Nicola Schneider
- I. Physik. Institut, University of Cologne, Zülpicher Str. 77, 50937 Cologne, Germany
| | - Robert Simon
- I. Physik. Institut, University of Cologne, Zülpicher Str. 77, 50937 Cologne, Germany
| | - Slawa Kabanovic
- I. Physik. Institut, University of Cologne, Zülpicher Str. 77, 50937 Cologne, Germany
| | - Rolf Güsten
- Max-Planck Institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, Germany
| | - Annie Zavagno
- Aix Marseille Université, CNRS, CNES, LAM, Marseille, France
| | - Patrick S Broos
- Department of Astronomy and Astrophysics, 525 Davey Laboratory, Pennsylvania State University, University Park, PA 16802, USA
| | - Christof Buchbender
- I. Physik. Institut, University of Cologne, Zülpicher Str. 77, 50937 Cologne, Germany
| | - Cristian Guevara
- I. Physik. Institut, University of Cologne, Zülpicher Str. 77, 50937 Cologne, Germany
| | - Karl Jacobs
- I. Physik. Institut, University of Cologne, Zülpicher Str. 77, 50937 Cologne, Germany
| | - Matthias Justen
- I. Physik. Institut, University of Cologne, Zülpicher Str. 77, 50937 Cologne, Germany
| | - Bernd Klein
- Max-Planck Institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, Germany
| | - Dylan Linville
- Department of Physics and Astronomy, West Virginia University, Morgantown, WV 26506, USA
- Center for Gravitational Waves and Cosmology, West Virginia University, Chestnut Ridge Research Building, Morgantown, WV 26505, USA
| | - Markus Röllig
- I. Physik. Institut, University of Cologne, Zülpicher Str. 77, 50937 Cologne, Germany
| | | | - Jürgen Stutzki
- I. Physik. Institut, University of Cologne, Zülpicher Str. 77, 50937 Cologne, Germany
| | - Maitraiyee Tiwari
- Max-Planck Institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, Germany
- Department of Astronomy, University of Maryland, College Park, MD 20742, USA
| | - Leisa K Townsley
- Department of Astronomy and Astrophysics, 525 Davey Laboratory, Pennsylvania State University, University Park, PA 16802, USA
| | - Alexander G G M Tielens
- Department of Astronomy, University of Maryland, College Park, MD 20742, USA
- Leiden Observatory, Leiden University, PO Box 9513, 2300 RA Leiden, Netherlands
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Pabst CHM, Goicoechea JR, Teyssier D, Berné O, Higgins RD, Chambers ET, Kabanovic S, Güsten R, Stutzki J, Tielens AGGM. Expanding bubbles in Orion A: [C II] observations of M42, M43, and NGC 1977. ASTRONOMY AND ASTROPHYSICS 2020; 639:A2. [PMID: 33173232 PMCID: PMC7116338 DOI: 10.1051/0004-6361/202037560] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
CONTEXT The Orion Molecular Cloud is the nearest massive-star forming region. Massive stars have profound effects on their environment due to their strong radiation fields and stellar winds. Stellar feedback is one of the most crucial cosmological parameters that determine the properties and evolution of the interstellar medium in galaxies. AIMS We aim to understand the role that feedback by stellar winds and radiation play in the evolution of the interstellar medium. Velocity-resolved observations of the [C II] 158μm fine-structure line allow us to study the kinematics of UV-illuminated gas. Here, we present a square-degree-sized map of [C II] emission from the Orion Nebula complex at a spatial resolution of 16″ and high spectral resolution of 0.2kms-1, covering the entire Orion Nebula (M42) plus M43 and the nebulae NGC 1973, 1975, and 1977 to the north. We compare the stellar characteristics of these three regions with the kinematics of the expanding bubbles surrounding them. METHODS We use [C II] 158μm line observations over an area of 1.2deg2 in the Orion Nebula complex obtained by the upGREAT instrument onboard SOFIA. RESULTS The bubble blown by the O7V star θ 1 Ori C in the Orion Nebula expands rapidly, at 13kms-1. Simple analytical models reproduce the characteristics of the hot interior gas and the neutral shell of this wind-blown bubble and give us an estimate of the expansion time of 0.2 Myr. M43 with the B0.5V star NU Ori also exhibits an expanding bubble structure, with an expansion velocity of 6kms-1. Comparison with analytical models for the pressure-driven expansion of H II regions gives an age estimate of 0.02 Myr. The bubble surrounding NGC 1973, 1975, and 1977 with the central B1V star 42 Orionis expands at 1.5kms-1, likely due to the over-pressurized ionized gas as in the case of M43. We derive an age of 0.4 Myr for this structure. CONCLUSIONS We conclude that the bubble of the Orion Nebula is driven by the mechanical energy input by the strong stellar wind from θ 1 Ori C, while the bubbles associated with M43 and NGC 1977 are caused by the thermal expansion of the gas ionized by their central later-type massive stars.
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Affiliation(s)
- C H M Pabst
- Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden, Netherlands
| | - J R Goicoechea
- Instituto de Fisica Fundamental, CSIC, Calle Serrano 121-123, 28006 Madrid, Spain
| | - D Teyssier
- Telespazio Vega UK Ltd. for ESA/ESAC, Urbanizacion Villafranca del Castillo, 28691 Madrid, Spain
| | - O Berné
- IRAP, Université de Toulouse, CNRS, CNES, UPS, 9 Av. colonel Roche, 31028 Toulouse Cedex 4, France
| | - R D Higgins
- I. Physikalisches Institut der Universität zu Köln, Zülpicher Strasse 77, 50937 Köln, Germany
| | - E T Chambers
- USRA/SOFIA, NASA Ames Research Center, Mail Stop 232-12, Building N232, P.O. Box 1, Moffett Field, CA 94035-0001, USA
| | - S Kabanovic
- I. Physikalisches Institut der Universität zu Köln, Zülpicher Strasse 77, 50937 Köln, Germany
| | - R Güsten
- Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, Germany
| | - J Stutzki
- I. Physikalisches Institut der Universität zu Köln, Zülpicher Strasse 77, 50937 Köln, Germany
| | - A G G M Tielens
- Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden, Netherlands
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Goicoechea JR, Santa-Maria MG, Bron E, Teyssier D, Marcelino N, Cernicharo J, Cuadrado S. Molecular tracers of radiative feedback in Orion (OMC-1) Widespread CH + ( J = 1-0), CO (10-9), HCN (6-5), and HCO + (6-5) emission. ASTRONOMY AND ASTROPHYSICS 2019; 622:A91. [PMID: 30820064 PMCID: PMC6390943 DOI: 10.1051/0004-6361/201834409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Young massive stars regulate the physical conditions, ionization, and fate of their natal molecular cloud and surroundings. It is important to find tracers that help quantifying the stellar feedback processes that take place at different spatial scales. We present ~85 arcmin2 (~1.3 pc2) velocity-resolved maps of several submillimeter molecular lines, taken with Herschel/HIFI, toward the closest high-mass star-forming region, the Orion molecular cloud 1 core (OMC-1). The observed rotational lines include probes of warm and dense molecular gas that are difficult, if not impossible, to detect from ground-based telescopes: CH+ (J = 1-0), CO (J = 10-9), HCO+ (J = 6-5) and HCN (J = 6-5), and CH (N, J =1, 3/2-1, 1/2). These lines trace an extended but thin layer (A V ≃3-6 mag or ~1016 cm) of molecular gas at high thermal pressure, P th = n H · T k ≈ 107 - 109 cm-3 K, associated with the far ultraviolet (FUV) irradiated surface of OMC-1. The intense FUV radiation field, emerging from massive stars in the Trapezium cluster, heats, compresses and photoevaporates the cloud edge. It also triggers the formation of specific reactive molecules such as CH+. We find that the CH+ (J = 1-0) emission spatially correlates with the flux of FUV photons impinging the cloud: G 0 from ~103 to ~105. This correlation is supported by constant-pressure photodissociation region (PDR) models in the parameter space P th/G 0 ≈ [5 · 103 - 8 · 104] cm-3 K where many observed PDRs seem to lie. The CH+ (J = 1-0) emission spatially correlates with the extended infrared emission from vibrationally excited H2 (v ≥ 1), and with that of [C ii] 158 μm and CO J = 10-9, all emerging from FUV-irradiated gas. These correlations link the presence of CH+ to the availability of C+ ions and of FUV-pumped H2 (v ≥ 1) molecules. We conclude that the parsec-scale CH+ emission and narrow-line (Δv ≃ 3 km s-1) mid-J CO emission arises from extended PDR gas and not from fast shocks. PDR line tracers are the smoking gun of the stellar feedback from young massive stars. The PDR cloud surface component in OMC-1, with a mass density of 120-240 M ⊙ pc-2, represents ~5% to ~10% of the total gas mass, however, it dominates the emitted line luminosity; the average CO J = 10-9 surface luminosity in the mapped region being ~35 times brighter than that of CO J = 2-1. These results provide insights into the source of submillimeter CH+ and mid-J CO emission from distant star-forming galaxies.
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Affiliation(s)
- Javier R Goicoechea
- Instituto de Física Fundamental (CSIC). Calle Serrano 121, E-28006, Madrid, Spain
| | - Miriam G Santa-Maria
- Instituto de Física Fundamental (CSIC). Calle Serrano 121, E-28006, Madrid, Spain
| | - Emeric Bron
- Instituto de Física Fundamental (CSIC). Calle Serrano 121, E-28006, Madrid, Spain
| | - David Teyssier
- Telespazio Vega UK Ltd for ESA/ESAC. Urbanización Villafranca del Castillo, Villanueva de la Cañada, E-28692 Madrid, Spain
| | - Nuria Marcelino
- Instituto de Física Fundamental (CSIC). Calle Serrano 121, E-28006, Madrid, Spain
| | - José Cernicharo
- Instituto de Física Fundamental (CSIC). Calle Serrano 121, E-28006, Madrid, Spain
| | - Sara Cuadrado
- Instituto de Física Fundamental (CSIC). Calle Serrano 121, E-28006, Madrid, Spain
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Pabst C, Higgins R, Goicoechea JR, Teyssier D, Berne O, Chambers E, Wolfire M, Suri ST, Guesten R, Stutzki J, Graf UU, Risacher C, Tielens AGGM. Disruption of the Orion molecular core 1 by wind from the massive star θ 1 Orionis C. Nature 2019; 565:618-621. [PMID: 30617315 DOI: 10.1038/s41586-018-0844-1] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 12/05/2018] [Indexed: 11/10/2022]
Abstract
Massive stars inject mechanical and radiative energy into the surrounding environment, which stirs it up, heats the gas, produces cloud and intercloud phases in the interstellar medium, and disrupts molecular clouds (the birth sites of new stars1,2). Stellar winds, supernova explosions and ionization by ultraviolet photons control the lifetimes of molecular clouds3-7. Theoretical studies predict that momentum injection by radiation should dominate that by stellar winds8, but this has been difficult to assess observationally. Velocity-resolved large-scale images in the fine-structure line of ionized carbon ([C II]) provide an observational diagnostic for the radiative energy input and the dynamics of the interstellar medium around massive stars. Here we report observations of a one-square-degree region (about 7 parsecs in diameter) of Orion molecular core 1-the region nearest to Earth that exhibits massive-star formation-at a resolution of 16 arcseconds (0.03 parsecs) in the [C II] line at 1.9 terahertz (158 micrometres). The results reveal that the stellar wind originating from the massive star θ1 Orionis C has swept up the surrounding material to create a 'bubble' roughly four parsecs in diameter with a 2,600-solar-mass shell, which is expanding at 13 kilometres per second. This finding demonstrates that the mechanical energy from the stellar wind is converted very efficiently into kinetic energy of the shell and causes more disruption of the Orion molecular core 1 than do photo-ionization and evaporation or future supernova explosions.
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Affiliation(s)
- C Pabst
- Leiden Observatory, Leiden University, Leiden, The Netherlands
| | - R Higgins
- I. Physikalisches Institut der Universität zu Köln, Cologne, Germany
| | | | - D Teyssier
- Telespazio Vega UK for ESA/ESAC, Urbanizacion Villafranca del Castillo, Madrid, Spain
| | - O Berne
- IRAP, Université de Toulouse, CNRS, CNES, Université Paul Sabatier, Toulouse, France
| | - E Chambers
- USRA/SOFIA, NASA Ames Research Center, Moffett Field, CA, USA
| | - M Wolfire
- Department of Astronomy, University of Maryland, College Park, MD, USA
| | - S T Suri
- I. Physikalisches Institut der Universität zu Köln, Cologne, Germany
| | - R Guesten
- Max-Planck-Institut für Radioastronomie, Bonn, Germany
| | - J Stutzki
- I. Physikalisches Institut der Universität zu Köln, Cologne, Germany
| | - U U Graf
- I. Physikalisches Institut der Universität zu Köln, Cologne, Germany
| | - C Risacher
- Max-Planck-Institut für Radioastronomie, Bonn, Germany.,IRAM, St Martin d'Hères, France
| | - A G G M Tielens
- Leiden Observatory, Leiden University, Leiden, The Netherlands.
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