Related papers: Parsec-scale SiO Emission in an Infrared Dark Clou…
We attempt to characterise the chemical properties of a sample of massive clumps of IRDCs through multi-molecular line observations. We also search for possible evolutionary trends among the derived chemical parameters. The clumps are…
Massive stars play an important role in shaping the structure of galaxies. Infrared dark clouds (IRDCs), with their low temperatures and high densities, have been identified as the potential birthplaces of massive stars. In order to…
Infrared dark clouds (IRDCs) are thought to be potential hosts of the elusive early phases of high-mass star formation. Here we conduct an in-depth kinematic analysis of one such IRDC, G034.43+00.24 (Cloud F), using high sensitivity and…
In order to search for shocks in the very early stage of star formation, we performed single-point surveys of SiO J=1-0, 2-1 and 3-2 lines and the H$_2$CO $2_{12}-1_{11}$ line toward a sample of 100 high-mass starless clump candidates…
We present high angular resolution observations toward two massive star forming regions IRAS 18264-1152 and IRAS 23151+5912 with the Plateau de Bure Interferometer (PdBI) in the SiO (J=2-1) and H$^{13}$CO$^{+}$ (J=1-0) lines and at 1.3 mm…
We present results of a multi-line study of the filamentary infrared dark cloud G351.78-0.54 in the 1.3 and 0.8 mm wavelength bands. The lines of the three isotopologues of carbon monoxide CO, N$_2$H$^+$, CH$_3$CCH and HNCO were observed.…
We compare the CO 2-1 observations against previously taken CO 4-3 observations and analyze the spatial distribution of young stellar objects (YSO's) within the cloud using the Spitzer IRAC observations of the 30 Doradus complex. Both peaks…
Theoretical models suggest that massive stars form via disk-mediated accretion, with bipolar outflows playing a fundamental role. A recent study toward massive molecular outflows has revealed a decrease of the SiO line intensity as the…
Infrared Dark Clouds (IRDCs), condensed regions of the ISM with high column densities, low temperatures and high masses, are suspected sites of star formation. Thousands of IRDCs have already been identified. To date, it has not been…
The initial conditions of massive star and star cluster formation are expected to be cold, dense and high column density regions of the interstellar medium, which can reveal themselves via near, mid and even far-infrared absorption as…
We have obtained maps of the molecular emission within the central five arcminutes (12 pc) of the Galactic center (GC) in selected molecular tracers: SiO(2-1), HNCO(5_{0,5}-4_{0,4}), and the J=1-->0 transition of H^{13}CO+, HN^{13}C, and…
We present observations of the 3P1-3P0 fine structure transition of atomic carbon [CI], the J=3-2 transition of CO, as well as of the J=1-0 transitions of 13CO and C18O toward DR15, an HII region associated with two mid-infrared dark clouds…
The fine-structure line of [OI] at 63micron is an important diagnostic tool in different fields of astrophysics. However, our knowledge of this line relies on observations with low spectral resolution, and the real contribution of each…
We analyze the molecular gas and dust associated with the infrared dark cloud SDC 341.232-0.268 in order to investigate the characteristics and parameters of the gas, determine the evolutionary status of four embedded EGO candidates and…
Infrared dark clouds are massive, dense clouds seen in extinction against the IR Galactic background. Many of these objects appear to be on the verge of star and star cluster formation. Our aim is to understand the physical properties of…
We used the KOSMA 3m telescope to map the core 7'x5' of the Galactic massive star forming region W3Main in the two fine structure lines of atomic carbon and four mid-J transitions of CO and 13CO. The maps are centered on the luminous…
Aims. The main goal of the present study is to determine the fractional SiO abundance in high-mass star-forming cores, and to investigate its dependence on the physical conditions. In this way we wish to provide constraints on the chemistry…
We present spectrophotometric ISO imaging with the LWS and the CAM-CVF of the Serpens molecular cloud core. The LWS map is centred on the far infrared and submillimetre source SMM1 and its size is 8' x 8'. The fine structure line emission…
We present a parsec-scale molecular hydrogen (H$_2$ 1-0 S(1) at 2.12~\micron) outflow discovered from the UKIRT Widefield Infrared Survey for H$_2$. The outflow is located in the infrared dark cloud core MSXDC G053.11+00.05 MM1 at 1.7 kpc…
We present star formation activity in the infrared dark cloud (IRDC) G53.2, a remarkable IRDC located at Galactic coordinates $(l,b)\sim(53^{\circ}.2,\,0^{\circ}.0)$ based on the census of young stellar object (YSO) candidates. IRDC G53.2…