Globules and Pillars in Cygnus X I. Herschel Far-infrared imaging of the Cyg OB2 environment

Autor: Nicola Schneider, L. D. Anderson, A. Blazere, Glenn J. White, Ph. André, Doris Arzoumanian, M. G. Guarcello, Sylvain Bontemps, A. Roy, Ana Duarte-Cabral, Luigi Spinoglio, Tracey Hill, M. Hennemann, A. Marston, Kazi L.J. Rygl, F. Comerón, Vincent Minier, Markus Röllig, J. Di Francesco, Vera Könyves, Frédérique Motte, Nicholas J. Wright, Pascal Tremblin, Pierre Didelon
Přispěvatelé: DAM Île-de-France (DAM/DIF), Direction des Applications Militaires (DAM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), FORMATION STELLAIRE 2016, Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Procédés, Matériaux et Energie Solaire (PROMES), Université de Perpignan Via Domitia (UPVD)-Centre National de la Recherche Scientifique (CNRS), Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), KOSMA, I. Physikalisches Institut [Köln], Universität zu Köln = University of Cologne-Universität zu Köln = University of Cologne, Faculty of Arts and Science, Concordia University [Montreal], University of Exeter, Maison de la Simulation (MDLS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut National de Recherche en Informatique et en Automatique (Inria)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Universität zu Köln-Universität zu Köln, ITA, USA, GBR, FRA, DEU, ESP, CAN, CHL
Jazyk: angličtina
Rok vydání: 2016
Předmět:
Zdroj: Astronomy and Astrophysics-A&A
Astronomy and Astrophysics-A&A, 2016, pp.21. ⟨10.1051/0004-6361/201628328⟩
Astronomy and Astrophysics-A&A, EDP Sciences, 2016, pp.21
ISSN: 0004-6361
1432-0746
DOI: 10.1051/0004-6361/201628328⟩
Popis: The radiative feedback of massive stars on molecular clouds creates pillars, globules and other features at the interface between the HII region and molecular cloud. We present here Herschel observations between 70 and 500 micron of the immediate environment of the Cygnus OB2 association, performed within the HOBYS program. All structures were detected based on their appearance at 70 micron, and have been classified as pillars, globules, evaporating gasous globules (EGGs), proplyd-like objects, and condensations. From the 70 and 160 micron flux maps, we derive the local FUV field on the PDR surfaces. In parallel, we use a census of the O-stars to estimate the overall FUV-field, that is 10^3-10^4 G_0 close to the central OB cluster (within 10 pc) and decreases down to a few tens G_0, in a distance of 50 pc. From a SED fit to the four longest Herschel wavelengths, we determine column density and temperature maps and derive masses, volume densities and surface densities for these structures. We find that the morphological classification corresponds to distinct physical properties. Pillars and globules have the longest estimated photoevaporation lifetimes, a few 10^6 yr, while all other features should survive less than that. These lifetimes are consistent with that found in simulations of turbulent, UV-illuminated clouds. We propose a tentative evolutionary scheme in which pillars can evolve into globules, which in turn then evolve into EGGs, condensations and proplyd-like objects.
Received February 18, 2016; accepted April 5, 2016, by A&A
Databáze: OpenAIRE
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