Related papers: S-bearing molecules in Massive Dense Cores
We present the results of a survey of several tens of dense high mass star forming (HMSF) cores in three transitions of the SO molecule at 30 and 100 GHz with the 100-m Effelsberg and 20-m Onsala radio telescopes. The physical parameters of…
We present observations of the intermediate to massive star-forming region I05345+3157 using the molecular line tracer CS(2-1) with CARMA to reveal the properties of the dense gas cores. Seven gas cores are identified in the integrated…
We are addressing the sites of isolated low mass star formation in the solar neighbourhood, i.e. small cloud cores within one kiloparsec. We aim at determining the physical parameters of the cores, i.e., temperature, volume density, column…
Context: In cold and dense gas prior to the formation of young stellar objects, heavy molecular species (including CO) are accreted onto dust grains. Under these conditions H$_3^+$ and its deuterated isotopologues become more abundant,…
Aims. To understand the roles of infall and protostellar evolution on the envelopes of massive young stellar objects (YSOs). Methods. The chemical evolution of gas and dust is traced, including infall and realistic source evolution. The…
Investigating the physical and chemical structures of massive star-forming regions is critical for understanding the formation and the early evolution of massive stars. We performed a detailed line survey toward six dense cores named as…
We report the detection of the SiO (J = 2 - 1) transition from the massive cold dense core G333.125-0.562. The core remains undetected at wavelengths shorter than 70 micron and has compact 1.2 mm dust continuum. The SiO emission is…
We investigate the molecular evolution and D/H abundance ratios that develop as star formation proceeds from a dense-cloud core to a protostellar core, by solving a gas-grain reaction network applied to a 1-D radiative hydrodynamic model…
Massive stars form deeply embedded in dense molecular gas, which they stir and heat up and ionize. During an early phase, the ionization is confined to hypercompact HII regions, and the stellar radiation is entirely absorbed by dust, giving…
We present observations of 1.2-mm dust continuum emission, made with the Swedish ESO Submillimeter Telescope, towards eighteen luminous IRAS point sources, all with colors typical of compact HII regions and associated with CS(2-1) emission,…
We present molecular line imaging observations of three massive molecular outflow sources, G333.6-0.2, G333.1-0.4, and G332.8-0.5, all of which also show evidence for infall, within the G333 giant molecular cloud (GMC). All three are within…
(Abridged) We have observed CS and C17O lines, and 1.2 mm cont. emission towards a sample of 130 high-mass protostellar candidates with DEC<-30 deg. This is the first step of the southern extension of a project started more than a decade…
To characterize the initial conditions for intermediate- to high-mass star formation, we observed two Infrared Dark Clouds (IRDCs) that remain absorption features up to 70mum wavelength, with the PdBI in the 3.23mm dust continuum as well as…
The chemical evolution in high-mass star-forming regions is still poorly constrained. Studying the evolution of deuterated molecules allows to differentiate between subsequent stages of high-mass star formation regions due to the strong…
As the number of complex organic molecules (COMs) detected in the interstellar medium increases, it becomes important to place meaningful constraints on the formation pathways of these species. The molecular cloud SgrB2(N) is host to…
Three bright molecular line sources in G333 have recently been shown to exhibit signatures of infall. We describe a molecular line radiative transfer modelling process which is required to extract the infall signature from Mopra and Nanten2…
(Abridged) We present evidence that low-mass starless cores, the simplest units of star formation, are systematically differentiated in their chemical composition. Molecules including CO and CS almost vanish near the core centers, where the…
(Abridged) Aims. To investigate the first stages of the process of high-mass star formation, we selected a sample of massive clumps previously observed with the SEST at 1.2 mm and with the ATNF ATCA at 1.3 cm. We want to characterize the…
It is the purpose of this paper to rediscuss the circumstellar properties of S stars and to put these properties in perspective with our current understanding of the evolutionary status of S stars, in particular the intrinsic/extrinsic…
Phosphorus is a crucial element for the development of life, but so far P-bearing molecules have been detected only in a few astrophysical objects, hence its interstellar chemistry is almost totally unknown. Here we show new detections of…