相关论文: NEATH IV: an early onset of complex organic chemis…
We investigate the chemical and observational implications of repetitive transient dense core formation in molecular clouds. We allow a transient density fluctuation to form and disperse over a period of 1 Myr, tracing its chemical…
Astrochemistry is a well-established multidisciplinary field devoted to study molecules in space. While most astrochemists are oriented to observe molecules in the gas phase and reproduce their abundances by modeling the physical conditions…
During the formation of stars, the accretion of the surrounding material toward the central object is thought to undergo strong luminosity outbursts, followed by long periods of relative quiescence, even at the early stages of star…
(English) In this lecture I discuss recent progress in the understanding of the chemical evolution of protoplanetary disks that resemble our Solar system during the first ten million years. At the verge of planet formation, strong…
The presence of numerous complex organic molecules (COMs; defined as those containing six or more atoms) around protostars shows that star formation is accompanied by an increase of molecular complexity. These COMs may be part of the…
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…
This paper will review the basic concepts of gas-phase and grain surface chemistry of dense molecular clouds, where low mass and high mass stars form. The chemistry of cold pre-stellar cloud cores, where molecular freeze-out and deuterium…
It is now well known that a primordial chemistry, involving light elements produced during the nucleosynthesis period, might develop during the hydrogen post-recombination era. In particular, molecular ions and primordial molecules such as…
Star formation activity in molecular clouds is often found to be correlated with the amount of material above a column density threshold of $\sim 10^{22} \, {\rm cm^{-2}}$. Attempts to connect this column density threshold to a ${\it…
Pre-stellar cores represent the earliest stage of the star- and planet-formation process. By characterizing the physical and chemical structure of these cores we can establish the initial conditions for star and planet formation and…
Remote and in-situ observations of cometary gases have revealed the presence of a wealth of complex organic molecules, including carbon chains, alcohols, imines and the amino acid glycine. Such chemical complexity in cometary material…
My thesis work aims to study the inter-relation between various physical and chemical conditions in a wide range of astrophysical environments. Our studied regions range from the super-hot regions (i.e., nebular, photon-dominated, or…
Context: Chemical models of dense cloud cores often utilize the so-called pseudo-time-dependent approximation, in which the physical conditions are held fixed and uniform as the chemistry occurs. In this approximation, the initial…
A solar-type system starts from an initial molecular core that acquires organic complexity as it evolves. The so-called prestellar cores that can be studied are rare, which has hampered our understanding of how organic chemistry sets in and…
The most intriguing question related to the chemical evolution of protoplanetary disks is the genesis of pre-biotic organic molecules in the planet-forming zone. In this contribution we briefly review current observational knowledge of…
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…
Isolated dense molecular cores are investigated to study the onset of complex organic molecule formation in interstellar ice. Sampling three cores with ongoing formation of low-mass stars (B59, B335, and L483) and one starless core (L694-2)…
Recent observations have revealed the existence of Complex Organic Molecules (COMs) in cold dense cores and prestellar cores. The presence of these molecules in such cold conditions is not well understood and remains a matter of debate…
We present synthetic line observations of a simulated molecular cloud, utilising a self-consistent treatment of the dynamics and time-dependent chemical evolution. We investigate line emission from the three most common CO isotopologues…
To study the chemical evolution during the formation of molecular clouds, we model three types of clouds with different density structures: collapsing spherical, collapsing ellipsoidal, and static spherical profiles. The collapsing models…