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相关论文: Disentangling CO Chemistry in a Protoplanetary Dis…

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Molecular lines hold valuable information on the physical and chemical composition of disks around young stars, the likely progenitors of planetary systems. This invited contribution discusses techniques to calculate the molecular emission…

天体物理学 · 物理学 2017-01-18 Michiel Hogerheijde

The formation of protostellar discs is severely hampered by magnetic braking, as long as magnetic fields remain frozen in the gas. The latter condition depends on the levels of ionisation that characterise the innermost regions of a…

星系天体物理 · 物理学 2015-06-22 Marco Padovani , Daniele Galli , Patrick Hennebelle , Benoît Commerçon , Marc Joos

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,…

地球与行星天体物理 · 物理学 2025-11-19 Rob J. Spaargaren , Oliver Herbort , Haiyang S. Wang , Stephen J. Mojzsis , Paolo Sossi

(abridged) We analyse the evolution of the fractional ionisation in a steady-state protoplanetary disc with a vertical temperature gradient and with gas-grain chemistry including surface reactions. The ionisation due to stellar X-rays,…

天体物理学 · 物理学 2009-11-10 D. Semenov , D. Wiebe , Th. Henning

Chemical composition of a molecular cloud is highly sensitive to the physical properties of the cloud. In order to obtain the chemical composition around a star forming region, we carry out a two dimensional hydrodynamical simulation of the…

星系天体物理 · 物理学 2013-06-04 Ankan Das , Liton Majumdar , Sandip K. Chakrabarti , Sonali Chakrabarti

We have investigated the two-dimensional (R,Z) distribution of deuterated molecular species in circumstellar disks around young stellar objects. The abundance ratios between singly deuterated and normal molecules (``D/H ratios'') in disks…

天体物理学 · 物理学 2009-11-07 Y. Aikawa , E. Herbst

Understanding the collapse of clouds and the formation of protoplanetary disks is essential to understanding the formation of stars and planets. Infall and accretion, the mass-aggregation processes that occur at envelope and disk scales,…

CO is the most widely used observational tracer of molecular gas. The observable CO luminosity is translated to H_2 mass via a conversion factor, X_CO, which is a source of uncertainty and bias. Despite variations in X_CO, the…

星系天体物理 · 物理学 2020-11-18 Munan Gong , Eve C. Ostriker , Chang-Goo Kim , Jeong-Gyu Kim

Structures in circumstellar disks such as gaps and rings are often attributed to planets. This connection has been difficult to show unequivocally, as other processes may also produce these features. Particularly, a photoelectric…

地球与行星天体物理 · 物理学 2020-01-08 Areli Castrejon , Wladimir Lyra , Alexander J. W. Richert , Marc Kuchner

We calculate the ionisation fraction in protostellar disk models using two different gas-phase chemical networks, and examine the effect of turbulent mixing by modelling the diffusion of chemical species vertically through the disk. The aim…

天体物理学 · 物理学 2009-11-11 Martin Ilgner , Richard P. Nelson

This thesis summarises my scientific works in the field of thermo-chemical modelling of planet-forming discs since 2009, in particular the development of the Protoplanetary Disc Model (ProDiMo). By combining chemical rate networks with…

地球与行星天体物理 · 物理学 2023-12-07 Peter Woitke

(Abridged) The Central Molecular Zone (CMZ) of the Milky Way exhibits extreme conditions, including high gas densities, elevated temperatures, enhanced cosmic-ray ionization rates, and large-scale dynamics. Large-scale molecular surveys…

ABRIDGED. The analysis of spectral energy distributions (SEDs) of protoplanetary disks to determine their physical properties is known to be highly degenerate. Hence, a Bayesian analysis is required to obtain parameter uncertainties and…

地球与行星天体物理 · 物理学 2023-04-05 T. Kaeufer , P. Woitke , M. Min , I. Kamp , C. Pinte

Interstellar methanol is considered to be a parent species of larger, more complex organic molecules. A physicochemical simulation of infalling parcels of matter is performed for a low-mass star-forming system to trace the chemical…

太阳与恒星天体物理 · 物理学 2014-09-09 Maria N. Drozdovskaya , Catherine Walsh , Ruud Visser , Daniel Harsono , Ewine F. van Dishoeck

We have modeled self-consistently the density and temperature profiles of gas and dust in protoplanetary disks, taking into account irradiation from a central star. Making use of this physical structure, we have calculated the level…

天体物理学 · 物理学 2009-11-11 H. Nomura , T. J. Millar

The detection of gas in debris disks raises the question of whether this gas is a remnant from the primordial protoplanetary phase, or released by the collision of secondary bodies. In this paper we analyze ALMA observations at 1-1.5"…

太阳与恒星天体物理 · 物理学 2019-06-26 Antonio Hales , Uma Gorti , John Carpenter , Meredith Hughes , Kevin Flaherty

Complex organic molecules (COMs), the building blocks of life, have been extensively detected under various physical conditions, from quiescent clouds to star-forming regions. They therefore serve as excellent tracers for the local physical…

We examine changes in the molecular abundances resulting from increased heating due to a self-luminous planetary companion embedded within a narrow circumstellar disk gap. Using 3D models that include stellar and planetary irradiation, we…

太阳与恒星天体物理 · 物理学 2015-05-29 L. Ilsedore Cleeves , Edwin A. Bergin , Tim J. Harries

We study the relationship between molecular gas and dust in the California Molecular Cloud over an unprecedented dynamic range of cloud depth (Av = 3 - 60 magnitudes). We compare deep Herschel-based measurements of dust extinction with…

星系天体物理 · 物理学 2021-02-24 John Arban Lewis , Charles Lada , John Bieging , Anoush Kazarians , João Alves , Marco Lombardi