相关论文: Molecular Formation in Low-Metallicity Hot Cores
Hot molecular cores (HMCs) are intermediate stages of high-mass star formation and are also known for their rich emission line spectra at (sub-)mm wavebands. The observed spectral feature of HMCs such as total number of emission lines and…
Aims: We aim to simulate radial profiles of molecular abundances and the gas temperature in cold and heavily shielded starless cores by combining chemical and radiative transfer models. Methods: A determination of the dust temperature in a…
Many complex organic molecules (COMs) in star-forming regions are believed to form on dust grains. We thus expect both the reduced metallicity and dust-to-gas ratio in the outer Galaxy to have an impact on the chemical composition of these…
To study the impact of the initial effects of metallicity (i.e., the abundance of elements heavier than helium) on star formation and the formation of different molecular species, we searched for hot molecular cores in the sub-solar…
In star-forming regions, molecular cloud history and dynamics set the trend in the chemical composition. Ice formation, in particular, is affected by the evolution of physical conditions, which can lead to different ice compositions within…
Ions (e.g., H$_3^+$, H$_2$O$^+$) have been used extensively to quantify the cosmic-ray ionization rate (CRIR) in diffuse sightlines. However, measurements of CRIR in low-to-intermediate density gas environments are rare, especially when…
We present preliminary results of an extensive research project aimed at describing the physical and chemical conditions of hot molecular cores (HMCs). Using millimeter continuum and spectroscopic data extracted from the Atacama Large…
(Abridged) We aim to enlarge the number of known hot corinos and carry out a first comparative study with hot cores. The ultimate goal is to understand whether complex organic molecules form in the gas phase or on grain surfaces, and what…
We have studied four complex organic molecules (COMs), methyl formate ($CH_3OCHO$), dimethyl ether ($CH_3OCH_3$), formamide ($NH_2CHO$), and ethyl cyanide ($C_2H_5CN$), towards a large sample of 39 high-mass star-forming regions…
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…
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…
We investigate molecular evolution from a molecular cloud core to a first hydrostatic core in three spatial dimensions. We perform a radiation hydrodynamic simulation in order to trace fluid parcels, in which molecular evolution is…
During the process of star formation, the dense gas undergoes significant chemical evolution leading to the emergence of a rich variety of molecules associated with hot cores and hot corinos. However, the physical and chemical conditions…
Cosmic rays (CR) play an important role in dense molecular cores, affecting their thermal and dynamical evolution and initiating the chemistry. Several studies have shown that the formation of protostellar discs in collapsing clouds is…
The Large and Small Magellanic Clouds (LMC and SMC), gas-rich dwarf companions of the Milky Way, are the nearest laboratories for detailed studies on the formation and survival of complex organic molecules (COMs) under metal poor…
Recent observations of the pre-stellar core L1544 and the younger starless core L1498 have revealed that complex organic molecules (COMs) are enhanced in the gas phase toward their outer and intermediate-density shells. Our goal is to…
The outer Galaxy is characterized by a lower metallicity than regions near the Sun, suggesting differences in the formation and survival of molecules in star-forming regions. To understand chemical evolution across the Milky Way, deriving…
We investigate ionization and heating of gas in the dense, shielded clumps/cores of molecular clouds bathed by an influx of energetic, charged cosmic rays (CRs). These molecular clouds have complex structures, with substantial variation in…
The destiny of complex organic molecules (COMs) in star-forming regions is interlinked with various evolutionary phases. Therefore, identifying these species in diversified environments of identical star-forming regions would help to…
Warm cores (or hot corinos) around low-mass protostellar objects show a rich chemistry with strong spatial variations. This chemistry is generally attributed to the sublimation of icy mantles on dust grains initiated by the warming effect…