Related papers: Chemical changes during star formation: high- vers…
High mass stars form in groups or clusters within massive cores in dense molecular clumps with sizes of 1pc and masses of 200Msun which are important laboratories for high-mass star formation in order to study the initial conditions. We…
Aims: Accretion rates in low-mass protostars can be highly variable in time. Each accretion burst is accompanied by a temporary increase in luminosity, heating up the circumstellar envelope and altering the chemical composition of the gas…
The very inner structure of massive YSOs is difficult to trace. With conventional observational methods we often identify structures still several hundreds of AU in size. But we also need information about the innermost regions where the…
Episodic accretion is an important process in the evolution of young stars and their environment. The observed strong luminosity bursts of young stellar objects likely have a long lasting impact on the chemical evolution of the disk and…
We investigate to what degree local physical and chemical conditions are related to the evolutionary status of various objects in star-forming media. rho Oph A displays the entire sequence of low-mass star formation in a small volume of…
A detailed radiative transfer analysis of the observed continuum and molecular line emission toward the deeply embedded young stellar object IRAS 16293-2422 is performed. The continuum modelling is used to constrain the temperature and…
Even today in our Galaxy, stars form from gas cores in a variety of environments, which may affect the properties of resulting star and planetary systems. Here we study the role of pressure, parameterized via ambient clump mass surface…
Hydrides are simple compounds containing one or a few hydrogen atoms bonded to a heavier atom. They are fundamental precursor molecules in cosmic chemistry and many hydride ions have become observable in high quality for the first time…
We review the known properties of molecular outflows from low- and high-mass young stars. General trends among outflows are identified, and the most recent studies on the morphology, kinematics, energetics, and evolution of molecular…
Variability in young stellar objects (YSOs) can be caused by various time-dependent phenomena associated with star formation, including accretion rates, geometric changes in the circumstellar disks, stochastic hydromagnetic interactions…
During the collapse of massive stars, and the supernova type-II explosions, stellar matter reaches densities and temperatures which are similar to the ones obtained in intermediate-energy nucleus-nucleus collisions. The nuclear…
Increasing evidence shows that most stars in the Milky Way, including the Sun, are born in star-forming regions containing also high-mass stars, but due to both observational and theoretical challenges, our comprehension of their chemical…
Radiative transfer models of multi-transition observations are used to determine molecular abundances as functions of position in pre- and protostellar cores. The data require a "drop" abundance profile with radius, with high abundances in…
Carbon monoxide (CO) is the most abundant molecule after molecular hydrogen and is important for the chemistry in circumstellar envelopes around evolved stars. When modelling the strength and shape of molecular lines, the size of the CO…
A fundamental question in cometary science is whether the different dynamical classes of comets have different chemical compositions, which would reflect different initial conditions. From the ground or Earth orbit, radio and infrared…
(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…
Since molecules are ubiquitous in space, the study of the 'Molecular Universe' could unfold the mystery of the existing Interstellar medium. Star formation is linked to the chemical evolution processes. Thus, an analysis of the formation of…
The physical and chemical conditions in Class 0/I protostars are fundamental in unlocking the protostellar accretion process and its impact on planet formation. The aim is to determine which physical components are traced by different…
We present a spectroscopic follow-up of photometrically-selected young stellar object (YSO) candidates in the Central Molecular Zone of the Galactic center. Our goal is to quantify the contamination of this YSO sample by reddened giant…
The determination of chemical abundances in star-forming galaxies and the study of their evolution on cosmological timescales are powerful tools for understanding galaxy formation and evolution. This contribution presents the latest results…