Kinetic temperature of massive star-forming molecular clumps measured with formaldehyde IV. The ALMA view of N113 and N159W in the LMC

Abstract

We mapped the kinetic temperature structure of two massive star-forming regions, N113 and N159W, in the Large Magellanic Cloud (LMC). We have used $\sim$1\hbox{$.{}^{\prime \prime }$}6\,($\sim$0.4\,pc) resolution measurements of the para-H${}_2$CO\,$J_{{\mathrm{K}}_{\mathrm{a}}{\mathrm{K}}_{\mathrm{c}}}$\,=\,3${}_{03}$--2${}_{02}$, 3${}_{22}$--2${}_{21}$, and 3${}_{21}$--2${}_{20}$ transitions near 218.5\,GHz to constrain RADEX non-LTE models of the physical conditions. The gas kinetic temperatures derived from the para-H${}_2$CO line ratios 3${}_{22}$--2${}_{21}$/3${}_{03}$--2${}_{02}$ and 3${}_{21}$--2${}_{20}$/3${}_{03}$--2${}_{02}$ range from 28 to 105\,K in N113 and 29 to 68\,K in N159W. Distributions of the dense gas traced by para-H${}_2$CO agree with those of the 1.3\,mm dust and \emph{Spitzer}\,8.0\,$\mu$m emission, but do not significantly correlate with the H$\alpha$ emission. The high kinetic temperatures ($T_{\mathrm{kin}}$\,$\gtrsim$\,50\,K) of the dense gas traced by para-H${}_2$CO appear to be correlated with the embedded infrared sources inside the clouds and/or YSOs in the N113 and N159W regions. The lower temperatures ($T_{\mathrm{kin}}$\,$<$\,50\,K) are measured at the outskirts of the H${}_2$CO-bearing distributions of both N113 and N159W. It seems that the kinetic temperatures of the dense gas traced by para-H${}_2$CO are weakly affected by the external sources of the H$\alpha$ emission. The non-thermal velocity dispersions of para-H${}_2$CO are well correlated with the gas kinetic temperatures in the N113 region, implying that the higher kinetic temperature traced by para-H${}_2$CO is related to turbulence on a $\sim$0.4\,pc scale. The dense gas heating appears to be dominated by internal star formation activity, radiation, and/or turbulence. It seems that the mechanism heating the dense gas of the star-forming regions in the LMC is consistent with that in Galactic massive star-forming regions located in the Galactic plane.

Accepted for publication in A&A

References in corpus (29)

• The Two Young Star Disks in the Central Parsec of the Galaxy: Properties, Dynamics and Formation
• An eclipsing binary distance to the Large Magellanic Cloud accurate to 2 per cent
• A distance to the Large Magellanic Cloud that is precise to one per cent
• The Critical Density and the Effective Excitation Density of Commonly Observed Molecular Dense Gas Tracers
• VLA observations of ammonia in high-mass star formation regions
• Abundances and Isotope Ratios in the Magellanic Clouds: The Star Forming Environment of N113
• Formaldehyde Densitometry of Starburst Galaxies
• Spitzer View of Young Massive Stars in the LMC HII Complexes. II. N159
• Thermal Feedback in the high-mass star and cluster forming region W51
• A systematic TMRT observational study of Galactic ${}^{12}$C/${}^{13}$C ratios from Formaldehyde
• The Stellar Mass Spectrum in Warm and Dusty Gas: Deviations from Salpeter in the Galactic Centre and in Circum-Nuclear Starburst Regions
• The Detection of Hot Cores and Complex Organic Molecules in the Large Magellanic Cloud
• 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
• The dense gas mass fraction in the W51 cloud and its protoclusters
• Formaldehyde as a Tracer of Extragalactic Molecular Gas I. Para-H_2CO Emission From M 82
• Diversity of chemistry and excitation conditions in the high-mass star forming complex W33
• Galactic H2CO Densitometry I: Pilot survey of Ultracompact HII regions and methodology
• Kinetic temperature of massive star forming molecular clumps measured with formaldehyde
• Dense Clumps in Giant Molecular Clouds in the Large Magellanic Cloud: Density and Temperature Derived from ${}^{13}$CO($J=3-2$) Observations
• Deuteration around the ultracompact HII region Mon R2
• ALMA Observations of Massive Clouds in the Central Molecular Zone: Ubiquitous Protostellar Outflows
• Temperature structures in Galactic Center clouds - Direct evidence for gas heating via turbulence
• Submillimeter Line Emission from LMC N159W: a Dense, Clumpy PDR in a Low Metallicity Environment
• Strong irradiation of protostellar cores in Corona Australis
• Kinetic temperature of massive star-forming molecular clumps measured with formaldehyde. III. The Orion Molecular Cloud 1
• Kinetic temperature of massive star forming molecular clumps measured with formaldehyde. II. The Large Magellanic Cloud
• Spectroscopic study of the N159/N160 complex in the Large Magellanic Cloud
• Dense gas in local galaxies revealed by multiple tracers
• The physical and chemical structure of high-mass star-forming regions. Unraveling chemical complexity with the NOEMA large program "CORE"

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