Related papers: Carbon isotope fractionation in protoplanetary dis…
Gravitationally unstable disks can fragment and form bound objects provided that their cooling time is short. In protoplanetary disks radiative cooling is likely to be too slow to permit formation of planets by fragmentation within several…
The chemical composition of exoplanets is thought to be influenced by the composition of the disks in which they form. JWST observations have unveiled a variety of species in numerous nearby disks, showing significant variations in the C/O…
High spatial resolution observations of CO isotopologue line emission in protoplanetary disks at mid-inclinations (${\approx}$30-75{\deg}) allow us to characterize the gas structure in detail, including radial and vertical substructures,…
We study the influence of the turbulent transport on ice chemistry in protoplanetary disks, focusing on carbon and nitrogen bearing molecules. Chemical rate equations are solved with the diffusion term, mimicking the turbulent mixing in the…
We examine heating and cooling in protostellar disks using 3-D radiation-MHD calculations of a patch of the Solar nebula at 1 AU, employing the shearing-box and flux-limited radiation diffusion approximations. The disk atmosphere is ionized…
We discuss the chemical pre-conditions for planet formation, in terms of gas and ice abundances in a protoplanetary disk, as function of time and position, and the resulting chemical composition and cloud properties in the atmosphere when…
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…
CO is the most widely used gas tracer of protoplanetary disks. Its abundance is usually assumed to be an interstellar ratio throughout the warm molecular layer of the disk. But recent observations of low CO gas abundance in many…
In recent years the gas kinematics probed by molecular lines detected with ALMA has opened a new window to study protoplanetary disks. High spatial and spectral resolution observations have revealed the complexity of protoplanetary disk…
Aims: The two stable isotopes of nitrogen, 14N and 15N, exhibit a range of abundance ratios both inside and outside the solar system. The elemental ratio in the solar neighborhood is 440. Recent ALMA observations showed HCN/HC15N ratios…
Analysis of the gaseous component in protoplanetary disks can inform us about their thermal and physical structure, chemical composition, and kinematic properties, all of which are crucial for understanding various processes within the…
Observations conducted using the Atacama Large Millimeter/submillimeter Array on the protoplanetary disk around TW Hya show the nitrogen fractionation of HCN molecules in HC$^{14}$N/HC$^{15}$N $\sim$120 at a radius of $\sim$20 AU. In this…
In a disk around DM Tau, previous observation of 13CO (J=2-1 and 1-0 transitions) derived the 13CO gas temperature of \sim 13-20K, which is lower than the sublimation temperature of CO (20 K). We argue that the existence of such cold CO can…
Low-mass protostars are the extrasolar analogues of the natal Solar System. Sophisticated physicochemical models are used to simulate the formation of two protoplanetary discs from the initial prestellar phase, one dominated by viscous…
Finding and characterizing extrasolar Earth analogs will rely on interpretation of the planetary system's environmental context. The total budget and fractionation between C-H-O species sensitively affect the climatic and geodynamic state…
The composition of forming planets is strongly affected by the protoplanetary disc's thermal structure. This thermal structure is predominantly set by dust radiative transfer and viscous (accretional) heating and can be impacted by gaps -…
Standard stellar evolution theory is inconsistent with the observed isotopic carbon ratio, 12C/13C, in evolved stars. This theory is also inconsistent with the 3He/H abundance ratios observed in Galactic HII regions, when combined with…
Isotope abundance ratios play an important role in astronomy and planetary sciences, providing insights in the origin and evolution of the Solar System, interstellar chemistry, and stellar nucleosynthesis. In contrast to deuterium/hydrogen…
The compositions of the Solar System terrestrial bodies are fractionated from that of the Sun, where elemental depletions in the bulk rocky bodies correlate with element volatility, expressed in its 50% condensation temperature. However,…
Observations have revealed evidence of photochemical processing in protoplanetary disks. This processing occurs in the photon dominated layer, the optically thin regions of the disk high above the disk midplane. It remains unclear, however,…