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Observational Analysis of the Physical Conditions in Galactic and Extragalactic Active Star Forming Regions Lars Kristensen

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Observational Analysis of the Physical Conditions in Galactic and Extragalactic Active Star Forming Regions Lars Kristensen Observational analysis of the physical conditions in galactic and extragalactic active star forming regions Lars Kristensen To cite this version: Lars Kristensen. Observational analysis of the physical conditions in galactic and extragalactic active star forming regions. Astrophysics [astro-ph]. Observatoire de Paris, 2007. English. tel-00323729 HAL Id: tel-00323729 https://tel.archives-ouvertes.fr/tel-00323729 Submitted on 23 Sep 2008 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. T` P´ ´ D S O L E K LERMA LAMAP O P-M U´ C-P S 19 O 2007 ´ R: M. M.W INAF, F M. F.B IAS, O E: M. D.N J H,B M. B.N OAR, R M. D.R LESIA, P I´ : M. D.F IFA, Å M. G.P Fˆ IAS, O & LERMA, P D T` : M. J.-L. L LERMA, P/C Abstract English In my thesis observations of near-infrared rovibrational H2 emission in active star- forming regions are presented and analysed. The main subject of this work concerns mainly new observations of the Orion Molecular Cloud (OMC1) and particularly the BN-KL region. The data consist of images of individual H2 lines with high spatial resolution obtained both at the Canada-France-Hawaii Telescope and the ESO Very Large Telescope (VLT). With the high spatial resolution of the VLT it is possible to analyse in detail (down to 60 AU 0. 13) individual objects in the region. I have ∼ ′′ also analysed H2 and [FeII] emission from outflows in two dark clouds (Bok globules BHR71 and BHR137) and a high excitation blob in the Magellanic Clouds (N159-5). In the latter, data consist of long-slit spectra obtained at the ESO-VLT. In order to facilitate this work I ran a large grid of 25 000 shock models, produc- ∼ ing almost 400 Gb of results. These models are state-of-the-art and there is a large number of free parameters which can be adjusted. A large part of my project has been to analyse the results from this grid and make it publically available. Furthermore, as it turned out, not all results are equally reliable and I have had to develop methods for checking the consistency of the wealth of results obtained. But with the model results and a sound knowledge of shock physics it is now relatively straightforward to interpret the H2 and [FeII] data. The models allow me to predict the large-scale physical conditions in OMC1 such as density, shock velocities, magnetic field strengths, etc. Overall the preshock 5 7 3 density is of the order of 10 -10 cm− and shock velocities are in the interval 10- 1 ∼ 40 km s− . Another very interesting result is a new method developed for analysing bow shocks observed at high spatial resolution. For one isolated bow shock in 1 OMC1 I predict a shock velocity of 50 km s− and a preshock density of the order of 5 105 cm 3. The 3D velocity has recently been measured to 55 km s 1 providing an × − − independent check on our results. iii iv Abstract Français Je présente et j’analyse dans ma thèse des observations de l’émission dans l’in- frarouge proche de transitions rovibrationelles de H2 dans des régions de formation stellaire. Le sujet principal de ce travail concerne de nouvelles observations du nuage moléculaire d’Orion (OMC1) et en particulier de la région BN-KL. Les données sont constituées d’images des raies individuelles de H2 obtenues à haute résolution spatiale avec le Telescope Canada-France-Hawaii et avec l’ESO VLT. Grâce à la haute résolution spatiale du VLT il est possible d’analyser en détail (jusq’à 60 UA 0. 13) des objets individuels dans cette région. De plus, j’ai analysé l’émission de ∼ ′′ H2 et [FeII] dans des écoulements (« outflows ») présents dans deux nuages sombres (les globules de Bok BHR71 et BHR137) ainsi que dans un « blob » à haute excita- tion dans le grand nuage de Magellan (N159-5). Ici les données sont constituées de spectres en fente longue obtenus à l’ESO-VLT. Pour réaliser ce travail j’ai tout d’abord calculé une grille complète de modèles de chocs composée de 25 000 simulations (correspondant à 400 Go, environ). Ces ∼ modèles qui sont les plus récents comportent un grand nombre de paramètres libres qui peuvent être ajustés. Une grande partie de mon travail a été d’analyser les résultats de cette grille avant de les mettre en ligne. En effet les résultats ne sont pas tous crédibles, et il m’a donc fallu de développer des méthodes pour les vérifier. Mais avec une bonne compréhension du modèle et un solide sens de la physique des chocs, il est maintenant assez facile d’interpréter les données sur H2 et [FeII]. Les modèles me permettent ensuite de prédire les conditions physiques à grande échelle dans OMC1, par exemple la densité, la vitesse des chocs, l’intensité du champ 5 7 3 magnétique, etc. En général la densité du milieu avant le choc est 10 -10 cm− et 1 ∼ la vitesse de choc est dans la gamme 10-40 km.s− . Un autre résultat très interessant de mon travail est le développement d’une nouvelle méthode pour analyser les chocs en arc (« bow shocks ») observés à une haute résolution spatiale. Pour un choc en arc isolé je prédis une vitesse de choc de 50 km.s 1 et une densité avant le choc de ∼ − 5 105 cm 3. La vitesse 3D a été messurée très récemment à 55 km.s 1. Cela donne × − − une confirmation indépendante de nos résultats. Publications Refereed publications (see also Appendix D): I “Excitation conditions in the Orion Molecular Cloud obtained from observa- tions of ortho- and para-lines of H2”, L.E. Kristensen, T.L. Ravkilde, D. Field, J.-L. Lemaire, G. Pineau des Forêts 2007, A&A, 469, 561 II “Observational 2D model of H2 emission from bow shocks in the Orion Molec- ular Cloud”, L.E. Kristensen, T.L. Ravkilde, G. Pineau des Forêts, S. Cabrit, D. Field, J.-L. Lemaire, M. Gustafsson, submitted to A&A III “VLT/NACO near-infrared imaging and spectroscopy of N159-5 in the LMC HII complex N159”, G. Testor, J.L. Lemaire, L.E. Kristensen, D. Field, S. Diana 2007, A&A, 469, 459 IV “Model predictions of shock excited gas in the interstellar medium”, L.E. Kristensen, G. Pineau des Forêts, S. Cabrit, D. Field & J.-L. Lemaire, in final stages of preparation IV "3D modeling of H2 emission from bowshocks in the Orion Molecular Cloud", T.L. Ravkilde, L.E. Kristensen, S. Cabrit, G. Pineau des Forêts, D. Field and J.-L. Lemaire, in preparation Proceedings: “Excitation Mechanisms in the Orion Molecular Cloud Deduced from H • 2 Ortho- and Para-Lines Emission at High Spatial Resolution.” at “La sémaine Française d’Astronomie et d’Astrophysique”, Strasbourg, France, 2005 “Model results for shocked gas in active star forming regions”, at the • Molecules in Space and Laboratory conference, Paris, France, 2007 v Acknowledgements Remerciements Tout d’abord je voudrais remercier le directeur de ma thèse, Jean-Louis Lemaire pour m’avoir donner la chance de travailler ici en France pendant les trois ans de thèse. Je le remercie pour avoir confiance en moi et pour m’avoir donner une grande liberté dans le travail que j’ai fait. Je le remercie pour m’avoir donner la possibilité d’enseigner comme co-responsable en Astro+++ et pour m’avoir montrer son petit paradis dans les Alpes. Merci à mes deux « co-directeurs », Guillaume Pineau des Forêts et Sylvie Ca- brit, l’Observatoire de Paris. Merci beaucoup d’avoir pris le temps de m’écouter et d’être très motivant. Après chaque rendez-vous j’ai toujours envie à commencer de travailler. Et sûrtout merci de m’avoir donner la chance de travailler avec votre code de choc, je sais très bien que c’est un privelège. Merci aux rapporteurs, Malcolm Walmsley et François Boulanger. Vous avez amelioré cette thèse, ainsi que la reste du jury, David Neufeld, Brunella Nisini, Daniel Rouan, David Field et Guillaume Pineau des Forêts. Je voudrais remercier toute la groupe de Cergy, même si on n’a jamais travaillé sur le même sujet (en ordre alphabétique) : —Jean-Jacques Bousquet : Tu m’as vraiment apris la culture française, la cuisine française, la langue française, etc. A mon avis, tu es le français le plus français que je connais. Même si on n’a que travaillé une fois ensemble, je sais très bien la difference R entre l’inox et l’alu maintenant. Et grâce à toi je sais comment SolidWorks works ! —Henda Chaabouni : pour souvent apporter des petits gâteaux tunisiens (grâce à toi, je les adore maintenant) et pour toujours avoir un grand sourire. —Vincent Cobut : C’était un plaisir d’enseigner avec toi en AstroChemistry. —Emanuele Congiu è il primo sardo, che conosco ma sono certo che non è l’ul- timo! Grazie per insegnarmi come fare un caffé vero italiano e per insegnarmi le parolaccie italiane! Et surtout merci d’avoir pris le temps de m’apprendre l’italien (et un peu de français) pendant nos pauses café nombreuse.
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