Related papers: CH3CCH as a thermometer in warm molecular gas
(Abridged) Aims: We aim to use the progressive heating of the gas caused by the feedback of high-mass young stellar objects (YSOs) to prove the statistical validity of the most common schemes used to define an evolutionary sequence for…
For a general understanding of the physics involved in the star formation process, measurements of physical parameters such as temperature and density are indispensable. The chemical and physical properties of dense clumps of molecular…
Context. The gas kinetic temperature (TK) determines the physical and chemical evolution of the Interestellar Medium (ISM). However, obtaining reliable TK estimates usually requires expensive observations including the combination of…
The studies of the complex molecular emission lines in millimeter and submillimeter wavelengths towards the hot molecular cores demonstrate valuable details about the chemical complexity in the interstellar medium (ISM). We presented the…
Observations of multiple rotational transitions from a single molecule allow for unparalleled constraints on the physical conditions of the emitting region. We present an analysis of CS in TW~Hya using the $J=7-6$, $5-4$ and $3-2$…
The excitation temperature T_01 derived from the relative intensities of the J = 0 (para) and J = 1 (ortho) rotational levels of H2 has been assumed to be an accurate measure of the kinetic temperature in interstellar environments. In…
We report a new, reliable determination of the CN excitation temperature of diffuse molecular clouds in the Milky Way, based on ultra high spectral resolution observations. Our determination is based on CN $B^{2}\Sigma^{+}-X^{2}\Sigma^{+}$…
The 2023 perihelion passage of comet C/2022 E3 (ZTF) afforded an opportunity to measure the abundances and spatial distributions of coma volatiles in an Oort cloud comet at high spatial resolution near its close approach to Earth…
A new configurational temperature thermostat suitable for molecules with holonomic constraints is derived. This thermostat has a simple set of motion equations, can generate the canonical ensemble in both position and momentum space, acts…
We performed one-dimensional hydrodynamic simulations with detailed cooling, heating and chemical processes to examine the thermal stability of shocked gas in cold neutral medium (CNM) and molecular clouds. We find that both CNM and…
We present the results of a series of calculations studying the collapse of molecular cloud cores performed using a three-dimensional smoothed particle hydr odynamics code with radiative transfer in the flux-limited diffusion approximation.…
The results of spectral observations in the $\sim 84-92$ GHz frequency range of six objects in the southern sky containing dense cores and associated with regions of massive stars and star clusters formation are presented. The observations…
Methyl cyanide (CH3CN) and propyne (CH3CCH) are two molecules commonly used as gas thermometers for interstellar gas. They are detected in several astrophysical environments and in particular towards protostars. Using data of the low-mass…
We report ALMA continuum and molecular line observations at 0.1 pc resolution toward the super star cluster (SSC) candidate H72.97-69.39 in the N79 region of the LMC. The continuum emission has a sharp peak around the SSC candidate but is…
The 12C/13C isotope ratio has been derived towards numerous cold clouds (20-50 K) and a couple protoplanetary disks and exoplanet atmospheres. However, direct measurements of this ratio in the warm gas (>100 K) around young low-mass…
HCN is a molecule central to interstellar chemistry, since it is the simplest molecule containing a carbon-nitrogen bond and its solid state chemistry is rich. The aim of this work was to study the NH3 + HCN -> NH4+CN- thermal reaction in…
We aim to detect methylamine, CH$_{3}$NH$_{2}$, in a variety of hot cores and use it as a test for the importance of photon-induced chemistry in ice mantles and mobility of radicals. Specifically, CH$_3$NH$_2$ cannot be formed from atom…
Recently, single crystalline carbon nitride 2D material with a C3N stoichiometry has been synthesized. In this investigation, we explored the mechanical response and thermal transport along pristine, free-standing and single-layer C3N. To…
Methylammonium lead iodide (CH3NH3PbI3) based solar cells have shown impressive power conversion efficiencies of above 20%. However, the microscopic mechanism of the high photovoltaic performance is yet to be fully understood. Particularly,…
The circumstellar ammonia (NH$_3$) chemistry in evolved stars is poorly understood. Previous observations and modelling showed that NH$_3$ abundance in oxygen-rich stars is several orders of magnitude above that predicted by equilibrium…