The supernova remnant G347.3À0.5 (J1713.7À3946) is known as one of the unique SNRs that emit TeV -rays, as well as nonthermal X-rays. We present a detailed study of molecular gas toward this SNR obtained with the 4 m millimeter and submillimeter telescope NANTEN at an angular resolution of 2A6. This study has revealed that several intensity peaks and the overall distribution of the molecular gas with radial velocities from À12 to À3 km s À1 show a remarkably good correlation with the X-ray features, strongly supporting the recently derived kinematic distance around 1 kpc, as opposed to the 6 kpc previously claimed. In addition, we show that absorption of X-rays is caused by local molecular gas at softer X-ray bands. Subsequent measurements of the submillimeter J ¼ 3 2 transition of CO made with the ASTE 10 m and CSO 10.4 m submillimeter telescopes toward three of the molecular intensity peaks have revealed higher excitation conditions, most likely higher temperatures above $30 K , in contrast to the typical gas temperature, 10 K, in low-mass dark clouds. This temperature rise is most likely caused by enhanced heating by the high-energy events in the SNR, where possible mechanisms include heating by X-rays, -rays, and/or cosmic-ray protons, although we admit that additional radiative heating by young protostars embedded may be working as well. In one of the CO peaks, we have confirmed the presence of broad molecular wings of $20 km s À1 velocity extent in the CO J ¼ 3 2 transition. Two alternative interpretations for the wings are presented; one is shock acceleration by the blast wave, and the other is molecular outflow driven by an embedded protostar. The SNR evolution is well explained as the free expansion phase based on the distance of 1 kpc. The molecular data set should be valuable for making a further detailed comparison with the -ray and X-ray distributions in order to examine the cosmic-ray acceleration quantitatively. Subject headingg s: cosmic rays -ISM: individual (SNR J1713.37À3946) -ISM: kinematics and dynamicssupernova remnants

Context. The Carina region is an excellent astrophysical laboratory for studying the feedback mechanisms of newly born, very massive stars within their natal giant molecular clouds (GMCs) at only 2.35 kpc distance. Aims. We use a clumpy PDR model to analyse the observed intensities of atomic carbon and CO and to derive the excitation conditions of the gas.Methods. The NANTEN2-4 m submillimeter telescope was used to map the [C i] 3 P 1 − 3 P 0 , 3 P 2 − 3 P 1 and CO 4-3, 7-6 lines in two 4 × 4 regions of Carina where molecular material interfaces with radiation from the massive star clusters. One region is the northern molecular cloud near the compact OB cluster Tr 14, and the second region is in the molecular cloud south of η Car and Tr 16. These data were combined with 13 CO SEST spectra, HIRES/IRAS 60 µm and 100 µm maps of the FIR continuum, and maps of 8 µm IRAC/Spitzer and MSX emission. Results. We used the HIRES far-infrared dust data to create a map of the FUV field heating the gas. The northern region shows an FUV field of a few 10 3 in Draine units while the field of the southern region is about a factor 10 weaker. While the IRAC 8 µm emission lights up at the edges of the molecular clouds, CO and also [C i] appear to trace the H 2 gas column density. The northern region shows a complex velocity and spatial structure, while the southern region shows an edge-on PDR with a single Gaussian velocity component. We constructed models consisting of an ensemble of small spherically symmetric PDR clumps within the 38 beam (0.43 pc), which follow canonical power-law mass and mass-size distributions. We find that an average local clump density of 2 × 10 5 cm −3 is needed to reproduce the observed line emission at two selected interface positions. Conclusions. Stationary, clumpy PDR models reproduce the observed cooling lines of atomic carbon and CO at two positions in the Carina Nebula.

Context. Star formation at earlier cosmological times took place in an interstellar medium with low metallicity. The Large Magellanic Cloud (LMC) is ideally suited to study star formation in such an environment. Aims. The physical and chemical state of the ISM in a star forming environment can be constrained by observations of submm and FIR spectral lines of the main carbon carrying species, CO, C i and C ii, which originate in the surface layers of molecular clouds illuminated by the UV radiation of the newly formed, young stars. Methods. We present high-angular resolution sub-millimeter observations in the N159W region in the LMC obtained with the NANTEN2 telescope of the 12 CO J = 4 → 3, J = 7 → 6, and 13 CO J = 4 → 3 rotational and [C i]3 P 1 − 3 P 0 and 3 P 2 − 3 P 1 finestructure transitions. The 13 CO J = 4 → 3 and [C i] 3 P 2 − 3 P 1 transitions are detected for the first time in the LMC. We derive the physical and chemical properties of the low-metallicity molecular gas using an escape probability code and a self-consistent solution of the chemistry and thermal balance of the gas in the framework of a clumpy cloud PDR model. Results. The separate excitation analysis of the submm CO lines and the carbon fine structure lines shows that the emitting gas in the N159W region has temperatures of about 80 K and densities of about 10 4 cm −3 . The estimated C to CO abundance ratio close to unity is substantially higher than in dense massive star-forming regions in the Milky Way. The analysis of all observed lines together, including the [C ii] line intensity reported in the literature, in the context of a clumpy cloud PDR model constrains the UV intensity to about χ ≈ 220 and an average density of the clump ensemble of about 10 5 cm −3 , thus confirming the presence of high density material in the LMC N159W region.

Aims. We aim at deriving the excitation conditions of the interstellar gas as well as the local FUV intensities in the molecular cloud surrounding NGC 3603 to get a coherent picture of how the gas is energized by the central stars. Methods. The NANTEN2-4 m submillimeter antenna is used to map the [CI] 1-0, 2-1 and CO 4-3, 7-6 lines in a 2 × 2 region around the young OB cluster NGC 3603 YC. These data are combined with C 18 O 2-1 data, HIRES-processed IRAS 60 μm and 100 μm maps of the FIR continuum, and Spitzer/IRAC maps. Results. The NANTEN2 observations show the presence of two molecular clumps located south-east and south-west of the cluster and confirm the overall structure already found by previous CS and C 18 O observations. We find a slight position offset of the peak intensity of CO and [CI], and the atomic carbon appears to be further extended compared to the molecular material. We used the HIRES farinfrared dust data to derive a map of the FUV field heating the dust. We constrain the FUV field to values of χ = 3−6 × 10 3 in units of the Draine field across the clouds. Approximately 0.2 to 0.3% of the total FUV energy is re-emitted in the [CII] 158 μm cooling line observed by ISO. Applying LTE and escape probability calculations, we derive temperatures (T MM1 = 43 K, T MM2 = 47 K), column densities (N MM1 = 0.9 × 10 22 cm −2 , N MM2 = 2.5 × 10 22 cm −2 ) and densities (n MM1 = 3 × 10 3 cm −3 , n MM2 = 10 3 −10 4 cm −3 ) for the two observed molecular clumps MM1 and MM2. Conclusions. The cluster is strongly interacting with the ambient molecular cloud, governing its structure and physical conditions. A stability analysis shows the existence of gravitationally collapsing gas clumps which should lead to star formation. Embedded IR sources have already been observed in the outskirts of the molecular cloud and seem to support our conclusions.

Context. Studying molecular gas in the central regions of the star burst galaxies NGC 4945 and Circinus enables us to characterize the physical conditions and compare them to previous local and high-z studies. Aims. We estimate temperature, molecular density and column densities of CO and atomic carbon. Using model predictions we give a range of estimated CO/C abundance ratios. Methods. Using the new NANTEN2 4 m sub-millimeter telescope in Pampa La Bola, Chile, we observed for the first time CO 4-3 and [C i] 3 P 1 − 3 P 0 at the centers of both galaxies at linear scale of 682 pc and 732 pc respectively. We compute the cooling curves of 12 CO and 13 CO using radiative transfer models and estimate the physical conditions of CO and [CI].Results. 3 P 1 − 3 P 0 /CO 4-3 ratio of integrated intensities are large at 1.2 in NGC 4945 and 2.8 in Circinus. Combining previous CO J = 1−0, 2-1 and 3-2 and 13 CO J = 1−0, 2-1 studies with our new observations, the radiative transfer calculations give a range of densities, n(H 2 ) = 10 3 −3 × 10 4 cm −3 , and a wide range of kinetic temperatures, T kin = 20−100 K, depending on the density. To discuss the degeneracy in density and temperature, we study two representative solutions. In both galaxies the estimated total [CI] cooling intensity is stronger by factors of ∼1−3 compared to the total CO cooling intensity. The CO/C abundance ratios are 0.2−2, similar to values found in Galactic translucent clouds. Conclusions. Our new observations enable us to further constrain the excitation conditions and estimate the line emission of higher-J CO-and the upper [CI]-lines. For the first time we give estimates for the CO/C abundance ratio in the center regions of these galaxies. Future CO J = 7−6 and [CI] 2-1 observations will be important to resolve the ambiguity in the physical conditions and confirm the model predictions.