Universität zu Köln

Wu, Ronin, Bron, Emeric, Onaka, Takashi, Le Petit, Franck, Galliano, Frederic ORCID: 0000-0002-4414-3367, Languignon, David, Nakamura, Tomohiko and Okada, Yoko ORCID: 0000-0002-6838-6435 (2018). Constraining physical conditions for the PDR of Trumpler 14 in the Carina Nebula. Astron. Astrophys., 618. LES ULIS CEDEX A: EDP SCIENCES S A. ISSN 1432-0746

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Abstract

We investigate the physical conditions of the CO gas, based on the submillimeter imaging spectroscopy from a 2' x 7' (1.5 x 5 pc(2)) area near the young star cluster, Trumpler 14 of the Carina Nebula. The observations presented in this work are taken with the Fourier Transform Spectrometer (FTS) of the Spectral and Photometric Imaging REceiver (SPIRE) onboard the Herschel Space Observatory. The newly observed spectral lines include [CI] 370 mu m [CI] 609 mu m, and CO transitions from J = 4-3 to J = 13-12. Our field of view covers the edge of a cavity carved by Trumpler 14 about 1 Myr ago and marks the transition from H II regions to photo-dissociation regions. The observed CO intensities are the most prominent at the northwest region, Car I-E. With the state-of-the-art Meudon PDR code, we successfully derive the physical conditions, which include the thermal pressure (P) and the scaling factor of radiation fields (G(UV)), from the observed CO spectral line energy distributions (SLEDS) in the observed region. The derived G(UV) values generally show excellent agreement with the UV radiation fields created by nearby OB-stars and thus confirm that the main excitation source of the observed CO emission is the UV-photons provided by the massive stars. The derived thermal pressure is in the range 0.5-3 x 10(8)K cm(-3) with the highest values found along the ionization front in Car I-E region facing Trumpler 14, hinting that the cloud structure is similar to the recent observations of the Orion Bar. We also note a discrepancy at a local position (<0.17 x 0.17 pc(2)) between the photo-dissociation region (PDR) modeling result and the UV radiation fields estimated from nearby massive stars, which requires further investigation on nearby objects that could contribute to local heating, including outflow. Comparing the derived thermal pressure with the radiation fields, we report the first observationally derived and spatially resolved P similar to 2 x 10(4) G(UV) relationship. As direct comparisons of the modeling results to the observed (CO)-C-13, [O I] 63 mu m, and [C II] 158 mu m intensities are not straightforward, we urge the reader to be cautious when constraining the physical conditions of PDRs with combinations of (CO)-C-12, (CO)-C-13, [C I], [O I] 63 mu m, and [C II] 158 mu m observations.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Wu, Ronin UNSPECIFIED UNSPECIFIED UNSPECIFIED Bron, Emeric UNSPECIFIED UNSPECIFIED UNSPECIFIED Onaka, Takashi UNSPECIFIED UNSPECIFIED UNSPECIFIED Le Petit, Franck UNSPECIFIED UNSPECIFIED UNSPECIFIED Galliano, Frederic UNSPECIFIED orcid.org/0000-0002-4414-3367 UNSPECIFIED Languignon, David UNSPECIFIED UNSPECIFIED UNSPECIFIED Nakamura, Tomohiko UNSPECIFIED UNSPECIFIED UNSPECIFIED Okada, Yoko UNSPECIFIED orcid.org/0000-0002-6838-6435 UNSPECIFIED
URN:	urn:nbn:de:hbz:38-169438
DOI:	10.1051/0004-6361/201832595
Journal or Publication Title:	Astron. Astrophys.
Volume:	618
Date:	2018
Publisher:	EDP SCIENCES S A
Place of Publication:	LES ULIS CEDEX A
ISSN:	1432-0746
Language:	English
Faculty:	Unspecified
Divisions:	Unspecified
Subjects:	no entry
Uncontrolled Keywords:	Keywords Language PHOTON-DOMINATED REGIONS; ORION BAR; PHOTODISSOCIATION REGIONS; INTERSTELLAR-MEDIUM; RESOLUTION IMAGES; DUST TEMPERATURES; MOLECULAR CLOUDS; GAS-DISTRIBUTION; ETA-CARINAE; HII-REGIONS Multiple languages Astronomy & Astrophysics Multiple languages
Refereed:	Yes
URI:	http://kups.ub.uni-koeln.de/id/eprint/16943