Velocity resolved [CII], [CI], and CO observations of the N159 star-forming region in the Large Magellanic Cloud: a complex velocity structure and variation of the column densities

Abstract

The [CII]158um line is one of the dominant cooling lines in star-forming active regions. The commonly assumed clumpy UV-penetrated cloud models predict a [CII] line profile similar to that of CO. However, recent spectral-resolved observations show that they are often very different, indicating a more complex origin of the line emission including the dynamics of the source region. The aim of our study is to investigate the physical properties of the star-forming ISM in the Large Magellanic Cloud (LMC) by separating the origin of the emission lines spatially and spectrally. In this paper, we focus on the spectral characteristics and the origin of the emission lines, and the phases of carbon-bearing species in the N159 star-forming region in the LMC. We mapped a 4'x(3-4)' region in N159 in [CII]158um and [NII]205um with the GREAT on board SOFIA, and in CO(3-2), (4-3), (6-5), 13CO(3-2), and [CI]3P1-3P0 and 3P2-3P1 with APEX. The emission of all transitions observed shows a large variation in the line profiles across the map and between the different species. At most positions the [CII] emission line profile is substantially wider than that of CO and [CI]. We estimated the fraction of the [CII] integrated line emission that cannot be fitted by the CO line profile to be 20%-50%. We derived the relative contribution from C+, C, and CO to the column density in each velocity bin. The contribution from C+ dominates the velocity range far from the velocities traced by the dense molecular gas, and the region located between the CO cores of N159 W and E. We estimate the contribution of the ionized gas to the [CII] emission using the ratio to the [NII] emission to be < 19% to the [CII] emission at its peak position, and <15% over the whole observed region. Using the integrated line intensities, we present the spatial distribution of I([CII])/I(FIR). (abridged for arXiv)

16 pages with 14 figures, accepted for publication in A&A

References in corpus (11)

• Early Science with SOFIA, the Stratospheric Observatory for Infrared Astronomy
• GREAT: the SOFIA high-frequency heterodyne instrument
• [CII] 158$\mu$m Emission and Metallicity in PDRs
• The Chemical Enrichment History of the Large Magellanic Cloud
• GREAT/SOFIA atmospheric calibration
• Abundances and Isotope Ratios in the Magellanic Clouds: The Star Forming Environment of N113
• Spitzer View of Young Massive Stars in the LMC HII Complexes. II. N159
• Sub-millimeter Observations of Giant Molecular Clouds in the Large Magellanic Cloud: Temperature and Density as Determined from J=3-2 and J=1-0 transitions of CO
• Dense Clumps in Giant Molecular Clouds in the Large Magellanic Cloud: Density and Temperature Derived from ${}^{13}$CO($J=3-2$) Observations
• Submillimeter Line Emission from LMC N159W: a Dense, Clumpy PDR in a Low Metallicity Environment
• Spectroscopic study of the N159/N160 complex in the Large Magellanic Cloud

Cited by in corpus (23)

• Photodissociation and X-Ray Dominated Regions
• Submillimeter-HCN Diagram for an Energy Diagnostics in the Centers of Galaxies
• A milestone toward understanding PDR properties in the extreme environment of LMC-30Dor
• First Results from the $Herschel$ and ALMA Spectroscopic Surveys of the SMC: The Relationship Between [CII]-bright Gas and CO-bright Gas at Low Metallicity
• Characterizing the transition from diffuse atomic to dense molecular clouds in the Magellanic clouds with [CII], [CI], and CO
• Constraining physical conditions for the PDR of Trumpler 14 in the Carina Nebula
• Velocity profiles of [CII], [CI], CO, and [OI] and physical conditions in four star-forming regions in the Large Magellanic Cloud
• Comparing [CII], HI, and CO dynamics of nearby galaxies
• Discovery of Molecular and Atomic Clouds Associated with the Magellanic Superbubble 30 Doradus C
• Carbon gas in SMC low-metallicity star-forming regions
• Disentangling the ISM phases of the dwarf galaxy NGC 4214 using [CII] SOFIA/GREAT observations
• Characterizing the Multi-Phase Origin of [CII] Emission in M101 and NGC 6946 with Velocity Resolved Spectroscopy
• An Unbiased CO Survey Toward the Northern Region of the Small Magellanic Cloud with the Atacama Compact Array. I. Overview: CO Cloud Distributions
• Radiative and mechanical feedback into the molecular gas in the Large Magellanic Cloud. I. N159W
• A view of Large Magellanic Cloud HII regions N159, N132, and N166 through the 345 GHz window
• The fine structure line deficit in S 140
• Velocity resolved [CII] spectroscopy of the center and the BCLMP302 region of M33 (HerM33es)
• Physical conditions of the molecular gas in metal-poor galaxies
• SOFIA FEEDBACK Survey: The Pillars of Creation in [C II] and Molecular Lines
• Disentangling emission from star-forming regions in the Magellanic Clouds: Linking [OIII]88 micron and 24 micron
• Physical conditions in the gas phases of the giant HII region LMC-N11: II. Origin of [CII] and fraction of CO-dark gas
• First detection of CF${}^{+}$ in the Large Magellanic Cloud
• LMC+: Large-scale mapping of [CII] and [OIII] in the LMC molecular ridge, I. Dataset and line ratio analyses