PDRs4All: III. JWST's NIR spectroscopic view of the Orion Bar
Artikel i vetenskaplig tidskrift, 2024
Context. JWST has taken the sharpest and most sensitive infrared (IR) spectral imaging observations ever of the Orion Bar photodis-sociation region (PDR), which is part of the nearest massive star-forming region the Orion Nebula, and often considered to be the 'prototypical'strongly illuminated PDR.
Aims. We investigate the impact of radiative feedback from massive stars on their natal cloud and focus on the transition from the H II region to the atomic PDR -crossing the ionisation front (IF) -, and the subsequent transition to the molecular PDR -crossing the dissociation front (DF). Given the prevalence of PDRs in the interstellar medium and their dominant contribution to IR radiation, understanding the response of the PDR gas to far-ultraviolet (FUV) photons and the associated physical and chemical processes is fundamental to our understanding of star and planet formation and for the interpretation of any unresolved PDR as seen by JWST.
Methods. We used high-resolution near-IR integral field spectroscopic data from NIRSpec on JWST to observe the Orion Bar PDR as part of the PDRs4All JWST Early Release Science programme. We constructed a 3″ × 25″ spatio-spectral mosaic covering 0.97-5.27 μm at a spectral resolution R of ~2700 and an angular resolution of 0.075″-0.173″. To study the properties of key regions captured in this mosaic, we extracted five template spectra in apertures centred on the three H2 dissociation fronts, the atomic PDR, and the H II region. This wealth of detailed spatial-spectral information was analysed in terms of variations in the physical conditions-incident UV field, density, and temperature -of the PDR gas.
Results. The NIRSpec data reveal a forest of lines including, but not limited to, He I, H I, and C I recombination lines; ionic lines (e.g. Fe III and Fe II); O I and N I fluorescence lines; aromatic infrared bands (AIBs, including aromatic CH, aliphatic CH, and their CD counterparts); pure rotational and ro-vibrational lines from H2; and ro-vibrational lines from HD, CO, and CH+, with most of them having been detected for the first time towards a PDR. Their spatial distribution resolves the H and He ionisation structure in the Huygens region, gives insight into the geometry of the Bar, and confirms the large-scale stratification of PDRs. In addition, we observed numerous smaller-scale structures whose typical size decreases with distance from θ1 Ori C and IR lines from C I, if solely arising from radiative recombination and cascade, reveal very high gas temperatures (a few 1000 K) consistent with the hot irradiated surface of small-scale dense clumps inside the PDR. The morphology of the Bar, in particular that of the H2 lines, reveals multiple prominent filaments that exhibit different characteristics. This leaves the impression of a 'terraced'transition from the predominantly atomic surface region to the CO-rich molecular zone deeper in. We attribute the different characteristics of the H2 filaments to their varying depth into the PDR and, in some cases, not reaching the C+/C/CO transition. These observations thus reveal what local conditions are required to drive the physical and chemical processes needed to explain the different characteristics of the DFs and the photochemical evolution of the AIB carriers.
Conclusions. This study showcases the discovery space created by JWST to further our understanding of the impact radiation from young stars has on their natal molecular cloud and proto-planetary disk, which touches on star and planet formation as well as galaxy evolution.
Infrared: ISM
HII regions
Photon-dominated region (PDR)
ISM: individual objects: Orion Bar
Techniques: spectroscopic
Författare
Els Peeters
SETI Institute
Western University
Emilie Habart
Institut d'Astrophysique Spatiale
O. Berné
Institut de Recherche en Astrophysique et Planétologie (IRAP)
Ameek Sidhu
Western University
Ryan Chown
Western University
Dries Van De Putte
Space Telescope Science Institute (STScI)
Boris Trahin
Institut d'Astrophysique Spatiale
Ilane Schroetter
Institut de Recherche en Astrophysique et Planétologie (IRAP)
Amelie Canin
Institut de Recherche en Astrophysique et Planétologie (IRAP)
Felipe Alarcon
University of Michigan
Bethany Schefter
Western University
Baria Khan
Western University
Sofia Pasquini
Western University
A.G.G.M. Tielens
University of Maryland
Universiteit Leiden
M.G. Wolfire
University of Maryland
E. Dartois
Université Paris-Saclay
J.R. Goicoechea
Consejo Superior de Investigaciones Científicas (CSIC)
Alexandros Maragkoudakis
National Aeronautics and Space Administration (NASA)
Takashi Onaka
University of Tokyo
Meisei University
Marc W. Pound
University of Maryland
S. Vicente
Instituto de Astrofísica e Ciências do Espaço (IA)
Alain Abergel
Institut d'Astrophysique Spatiale
E. A. Bergin
University of Michigan
J. Bernard-Salas
CERGA (Centre d'Etudes et de Recherche de Grasse ACRI)
Innovative Common Laboratory For Space Spectroscopy (INCLASS)
Christiaan Boersma
National Aeronautics and Space Administration (NASA)
E. Bron
Observatoire de Paris
Jan Cami
Western University
S. Cuadrado
Consejo Superior de Investigaciones Científicas (CSIC)
D. Dicken
Royal Observatory
Meriem Elyajouri
Institut d'Astrophysique Spatiale
A. Fuente
Observatorio Astronómico Nacional (OAN)
K. Gordon
Universiteit Gent
Space Telescope Science Institute (STScI)
Lina Issa
Institut de Recherche en Astrophysique et Planétologie (IRAP)
C. Joblin
Institut de Recherche en Astrophysique et Planétologie (IRAP)
Olga Kannavou
Institut d'Astrophysique Spatiale
Ozan Lacinbala
Quantum Solid State Physics (QSP)
David Languignon
Observatoire de Paris
R. Le Gal
Institut de Radioastronomie Millimétrique (IRAM)
Institut de Planétologie et d’Astrophysique de Grenoble (IPAG)
Raphael Meshaka
Institut d'Astrophysique Spatiale
LERMA - Laboratoire d'Etudes du Rayonnement et de la Matiere en Astrophysique et Atmospheres
Yoko Okada
Universität zu Köln
Massimo Robberto
Space Telescope Science Institute (STScI)
Johns Hopkins University
M. Rollig
Johann Wolfgang Goethe Universität Frankfurt am Main
Physikalischer Verein
Thiébaut-Antoine Schirmer
Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik
Institut d'Astrophysique Spatiale
Benoît Tabone
Institut d'Astrophysique Spatiale
Marion Zannese
Institut d'Astrophysique Spatiale
I. Aleman
Universidade de Sao Paulo (USP)
Universidade Federal de Itajuba
Louis Allamandola
National Aeronautics and Space Administration (NASA)
Bay Area Environmental Research Institute (BAER)
Rebecca Auchettl
Australian Synchrotron (ANSTO)
Giuseppe Antonio Baratta
Istituto nazionale di astrofisica (INAF)
Salma Bejaoui
National Aeronautics and Space Administration (NASA)
Partha P. Bera
Bay Area Environmental Research Institute (BAER)
National Aeronautics and Space Administration (NASA)
John H Black
Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik
F. Boulanger
Laboratoire de Physique de l’Ecole Normale Supérieure
Jordy Bouwman
University of Colorado at Boulder
B. R. Brandl
Universiteit Leiden
TU Delft
Philippe Brechignac
Université Paris-Saclay
S. Brünken
Radboud Universiteit
Mridusmita Buragohain
University of Hyderabad
Andrew Burkhardt
Wellesley College
Alessandra Candian
Anton Pannekoek Institute for Astronomy
S. Cazaux
TU Delft
Jose Cernicharo
Consejo Superior de Investigaciones Científicas (CSIC)
Marin Chabot
Université Paris-Saclay
Shubhadip Chakraborty
Gitam School of Science
Université de Rennes 1
Jason Champion
Institut de Recherche en Astrophysique et Planétologie (IRAP)
Sean W. J. Colgan
National Aeronautics and Space Administration (NASA)
Ilsa R. Cooke
University of British Columbia (UBC)
A. Coutens
Institut de Recherche en Astrophysique et Planétologie (IRAP)
N. L. J. Cox
ACRI-ST
Observatoire de la Cote d'Azur
K. Demyk
Institut de Recherche en Astrophysique et Planétologie (IRAP)
Jennifer Donovan Meyer
National Radio Astronomy Observatory
Sacha Foschino
Institut de Recherche en Astrophysique et Planétologie (IRAP)
P. Garcia-Lario
European Space Astronomy Centre (ESAC)
M. Gerin
Observatoire de Paris
C. A. Gottlieb
Harvard-Smithsonian Center for Astrophysics
P. Guillard
Institut Universitaire de France
Institut d 'Astrophysique de Paris
Antoine Gusdorf
Laboratoire de Physique de l’Ecole Normale Supérieure
LERMA - Laboratoire d'Etudes du Rayonnement et de la Matiere en Astrophysique et Atmospheres
Patrick Hartigan
Rice University
J. H. He
Chinese Academy of Sciences
Universidad de Chile (UCH)
Yunnan Observatories
E Herbst
University of Virginia
Liv Hornekaer
Aarhus Universitet
Cornelia Jäger
Friedrich-Schiller-Universität Jena
Eduardo Janot-Pacheco
Universidade de Sao Paulo (USP)
M. Kaufman
San Jose State University
S. Kendrew
Europeiska rymdorganisationen (ESA)
M. S. Kirsanova
Russian Academy of Sciences
Pamela Klaassen
Royal Observatory
Sun Kwok
University of British Columbia (UBC)
A. Labiano
European Space Astronomy Centre (ESAC)
Thomas Lai
California Institute of Technology (Caltech)
Timothy J. Lee
National Aeronautics and Space Administration (NASA)
B. Lefloch
Université de Bordeaux
Franck Le Petit
Observatoire de Paris
Aigen Li
University of Missouri
H. Linz
Max-Planck-Gesellschaft
Cameron J. MacKie
Lawrence Berkeley National Laboratory
University of California at Berkeley
S. C. Madden
Université Paris-Saclay
Joëlle Mascetti
Institut des Sciences Moleculaires, Talence
Brett McGuire
Massachusetts Institute of Technology (MIT)
National Radio Astronomy Observatory
Pablo Merino
Consejo Superior de Investigaciones Científicas (CSIC)
Elisabetta R. Micelotta
Helsingin Yliopisto
K. A. Misselt
University of Arizona
Jon A. Morse
AstronetX
Giacomo Mulas
Istituto nazionale di astrofisica (INAF)
Institut de Recherche en Astrophysique et Planétologie (IRAP)
Naslim Neelamkodan
United Arab Emirates University
Ryou Ohsawa
National Astronomical Observatory of Japan
R. Paladini
California Institute of Technology (Caltech)
Maria Elisabetta Palumbo
Istituto nazionale di astrofisica (INAF)
Amit Pathak
Banaras Hindu University
Yvonne J. Pendleton
University of Central Florida
Annemieke Petrignani
Universiteit Van Amsterdam
Thomas Pino
Université Paris-Saclay
E. Puga
Europeiska rymdorganisationen (ESA)
Naseem Rangwala
National Aeronautics and Space Administration (NASA)
Mathias Rapacioli
UMR5626
Alessandra Ricca
SETI Institute
J. Roman-Duval
Space Telescope Science Institute (STScI)
Joseph Roser
SETI Institute
National Aeronautics and Space Administration (NASA)
Evelyne Roueff
Observatoire de Paris
Gaël Rouillé
Friedrich-Schiller-Universität Jena
Farid Salama
National Aeronautics and Space Administration (NASA)
Dinalva A. Sales
Estatística e Física
Karin Sandstrom
University of California
Peter Sarre
University of Nottingham
Ella Sciamma-O'Brien
National Aeronautics and Space Administration (NASA)
Kris Sellgren
Ohio State University
Sachindev S. Shenoy
Space Science Institute
D. Teyssier
European Space Astronomy Centre (ESAC)
Richard D. Thomas
Stockholms universitet
Aditya Togi
Texas State University
Laurent Verstraete
Institut d'Astrophysique Spatiale
Adolf N. Witt
University of Toledo
A. Wootten
National Radio Astronomy Observatory
Nathalie Ysard
Institut d'Astrophysique Spatiale
H. Zettergren
Stockholms universitet
Yong Zhang
Sun Yat-Sen University
Ziwei E. Zhang
RIKEN
Junfeng Zhen
Deep Space Exploration Laboratory (DSEL)
Publicerad i
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 685 art. nr A74Kategorisering
Ämneskategorier (SSIF 2011)
Astronomi, astrofysik och kosmologi
Atom- och molekylfysik och optik
Identifikatorer
DOI
10.1051/0004-6361/202348244