Submillimeter Line Emission from LMC 30Dor: The Impact of a Starburst on a Low Metallicity Environment

Abstract

(Abridged) The 30 Dor region in the Large Magellanic Cloud (LMC) is the most vigorous star-forming region in the Local Group. Star formation in this region is taking place in low-metallicity molecular gas that is exposed to an extreme far--ultraviolet (FUV) radiation field powered by the massive compact star cluster R136. We used the NANTEN2 telescope to obtain high-angular resolution observations of the 12CO 4-3, 7-6, and 13CO 4-3 rotational lines and [CI] 3P1-3P0 and 3P2-3P1 fine-structure submillimeter transitions in 30Dor-10, the brightest CO and FIR-emitting cloud at the center of the 30Dor region. We derived the properties of the low-metallicity molecular gas using an excitation/radiative transfer code and found a self-consistent solution of the chemistry and thermal balance of the gas in the framework of a clumpy cloud PDR model. We compared the derived properties with those in the N159W region, which is exposed to a more moderate far-ultraviolet radiation field compared with 30Dor-10, but has similar metallicity. We also combined our CO detections with previously observed low-J CO transitions to derive the CO spectral-line energy distribution in 30Dor-10 and N159W. The separate excitation analysis of the submm CO lines and the neutral carbon fine structure lines shows that the mid-J CO and [CI]-emitting gas in the 30Dor-10 region has a temperature of about 160 K and a H2 density of about 10^4 cm^-3. We find that the molecular gas in 30Dor-10 is warmer and has a lower beam filling factor compared to that of N159W, which might be a result of the effect of a strong FUV radiation field heating and disrupting the low--metallicity molecular gas. We use a clumpy PDR model (including the [CII] line intensity reported in the literature) to constrain the FUV intensity to about chi_0 ~ 3100 and an average total H density of the clump ensemble of about 10^5 cm^-3 in 30Dor-10.

11 pages, 8 figures. Accepted for publication in A&A

References in corpus (9)

• The Magellanic Mopra Assessment (MAGMA). I. The Molecular Cloud Population of the Large Magellanic Cloud
• [CII] 158$\mu$m Emission and Metallicity in PDRs
• 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
• A clumpy-cloud PDR model of the global far-infrared line emission of the Milky Way
• The cooling of atomic and molecular gas in DR21
• 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
• Clumpy photon-dominated regions in Carina. I. [CI] and mid-J CO lines in two 4'x4' fields

Cited by in corpus (16)

• An Overview of the Dwarf Galaxy Survey
• ALMA Resolves 30 Doradus: Sub-parsec Molecular Cloud Structure Near the Closest Super-Star Cluster
• ALMA reveals starburst-like interstellar medium conditions in a compact star-forming galaxy at z ~ 2 using [CI] and CO
• Extended [CII] Emission in Local Luminous Infrared Galaxies
• A milestone toward understanding PDR properties in the extreme environment of LMC-30Dor
• Spatially-resolved dust properties of the GRB 980425 host galaxy
• Characterizing the transition from diffuse atomic to dense molecular clouds in the Magellanic clouds with [CII], [CI], and CO
• Synthetic observations of star formation and the interstellar medium
• The headlight cloud in NGC 628: An extreme giant molecular cloud in a typical galaxy disk
• Velocity profiles of [CII], [CI], CO, and [OI] and physical conditions in four star-forming regions in the Large Magellanic Cloud
• Spatially resolved physical conditions of molecular gas and potential star formation tracers in M83, revealed by the Herschel SPIRE FTS
• From Gas to Stars in Energetic Environments: Dense Gas Clumps in the 30 Doradus Region Within the Large Magellanic Cloud
• Radiative and mechanical feedback into the molecular gas in the Large Magellanic Cloud. II. 30 Doradus
• Molecular and Ionized Hydrogen in 30 Doradus. I. Imaging Observations
• Physical conditions of the molecular gas in metal-poor galaxies
• Warm ISM in the Sgr A Complex. I: Mid-J CO, atomic carbon, ionized atomic carbon,and ionized nitrogen sub-mm/FIR line observations with the Herschel-HIFI and NANTEN2/SMART telescopes