Protoplanetary disks in massive star-forming regions may be exposed to ultraviolet radiation fields orders of magnitude stronger than the interstellar background. This intense radiation drives photoevaporative winds that fundamentally shape disk evolution and chemistry. However, full radiation hydrodynamic simulations of these systems remain computationally expensive, preventing systematic exploration of the parameter space. We present a parametric framework for efficiently generating density structures of externally irradiated protoplanetary disks with photoevaporative winds. Our approach implements a spherically diverging wind configuration with smooth transitions between the disk interior, the FUV-heated surface layer, and the wind itself. We validate this framework extensively against the FRIED grid of hydrodynamical simulations, demonstrating accurate reproduction of density structures across stellar masses from 0.3 to 3.0 M_sun, disk radii from 20 to 150 au, and external FUV fields from 100 to 100,000 G0. The complete framework is available as 'PUFFIN', a Python package that generates full 1D or 2D density structures in seconds to minutes, compared to weeks or months for equivalent hydrodynamical calculations. We demonstrate the scientific utility of this approach by modelling CO chemistry across a comprehensive parameter grid, using our density structures as inputs to thermochemical calculations. Our results show that external FUV irradiation significantly enhances CO gas-phase abundances through indirect heating mechanisms, which raise midplane temperatures and enhance thermal desorption of CO ice. This effect is strongest in the outer disk and scales with both external field strength and disk mass, with important implications for volatile budgets available to forming planets in clustered environments.
Computing the flow from externally FUV irradiated protoplanetary discs requires solving complicated and expensive photodissociation physics iteratively in conjunction with hydrodynamics. Previous studies have therefore been limited to 1D models of this process. In this paper we compare 2D-axisymmetric models of externally photoevaporating discs with their 1D analogues, finding that mass loss rates are consistent to within a factor four. The mass loss rates in 2D are higher, in part because half of the mass loss comes from the disc surface (which 1D models neglect). 1D mass loss rates used as t…
We present an open access grid of 3930 calculations of externally evaporating protoplanetary discs. This spans a range of disc sizes (1-400AU), disc masses, UV field strengths (10-10$^4$G$_0$) and stellar masses (0.05-1.9M$_\odot$). The grid is publicly available for download, and offers a means of cheaply including external photoevaporation in disc evolutionary calculations. It can also be queried using an online tool for quick estimates of instantaneous mass loss rates (e.g for convenient evaluation of real observed systems). The `FRIED' grid itself illustrates that for discs around stars $\…
(Abridged) The birth environment of the Sun will have influenced the conditions in the pre-solar nebula, including the attainable chemical complexity, important for prebiotic chemistry. The formation and distribution of complex organic molecules (COMs) in a disk around a T Tauri star is investigated for two scenarios: (i) an isolated disk, and (ii) a disk irradiated externally by a nearby massive star. The chemistry is calculated along the accretion flow from the outer disk inwards using a comprehensive network. Two simulations are performed, one beginning with complex ices and one with simple…
X-ray- and extreme-ultraviolet- (XEUV-) driven photoevaporative winds acting on protoplanetary disks around young T-Tauri stars may strongly impact disk evolution, affecting both gas and dust distributions. We compute dust densities for the wind regions of XEUV-irradiated transition disks with gap sizes of 20 and 30 AU, and determine whether they can be observed at wavelengths $0.7 \lesssim λ_\mathrm{obs} [μ\mathrm{m}] \lesssim 1.8$ in scattered and polarised light with current instrumentation. For an XEUV-driven outflow around a $M_* = 0.7 \mathrm{M}_\odot$ T-Tauri star with $L_X = 2 \cdot 10…
There is growing theoretical and observational evidence that protoplanetary disc evolution may be significantly affected by the canonical levels of far ultraviolet (FUV) radiation found in a star forming environment, leading to substantial stripping of material from the disc outer edge even in the absence of nearby massive stars. In this paper we perform the first full radiation hydrodynamic simulations of the flow from the outer rim of protoplanetary discs externally irradiated by such intermediate strength FUV fields, including direct modelling of the photon dominated region (PDR) which is r…
Characterizing the bolometric-photoevaporative transition in young sub-Neptunes with radiation-hydrodynamic simulations
Earth and Planets Laboratory, Carnegie Institution for Science（卡内基科学研究所地球与行星实验室）；Imperial Astrophysics, Department of Physics, Imperial College London（伦敦帝国理工学院物理系天文物理组）；Department of Earth, Planetary, and Space Sciences, The University of California, Los Angeles（加州大学洛杉矶分校地球、行星与空间科学系）
Substructure in externally irradiated protoplanetary disks, I. spirals and rings in two-dimensional radiation hydrodynamics
Ludwig-Maximilians-Universität München（路德维希-马克西米利安慕尼黑大学）；Astronomy Unit, School of Physics and Astronomy, Queen Mary University of London（伦敦大学玛丽女王学院物理与天文学系天文学单元）；Max Planck Institute for Astronomy（马克斯·普朗克天文学研究所）
Star formation often occurs within or nearby stellar clusters. Irradiation by nearby massive stars can photoevaporate protoplanetary disks around young stars (so-called proplyds) which raises questions regarding the ability of planet formation to take place in these environments. We investigate the two-dimensional physical and chemical structure of a protoplanetary disk surrounding a low-mass (T Tauri) star which is irradiated by a nearby massive O-type star to determine the survivability and observability of molecules in proplyds. Compared with an isolated star-disk system, the gas temperatur…
We demonstrate the utility of CI as a tracer of photoevaporative winds that are being driven from discs by their ambient UV environment. Commonly observed CO lines only trace these winds in relatively weak UV environments and are otherwise dissociated in the wind at the intermediate to high UV fields that most young stars experience. However, CI traces unsubtle kinematic signatures of a wind in intermediate UV environments ($\sim1000$G$_0$) and can be used to place constraints on the kinematics and temperature of the wind. In CI position-velocity diagrams external photoevaporation results in v…
XUE. ProDiMo models of internally and externally irradiated planet-forming disks around 0.3-4.0 solar mass stars (The IRIS project I)
Stockholm University（斯德哥尔摩大学）；Pennsylvania State University（宾夕法尼亚州立大学）；Space Research Institute, Austrian Academy of Sciences（奥地利科学院空间研究所）；Center for Exoplanets and Habitable Worlds, Penn State University（宾夕法尼亚州立大学系外行星与宜居世界中心）；Ludwig-Maximilians-Universität München（慕尼黑路德维希-马克西米利安大学）；Max-Planck-Institut für extraterrestrische Physik（马普地外物理研究所）；Max-Planck-Institut für Astronomie（马普天体物理研究所）；Radboud University（拉德堡德大学）
JWST-MIRI's multi-dimensional view of mass loss in the irradiated disks of NGC 1977
Center for Astrophysics | Harvard & Smithsonian（哈佛-史密森天体物理中心）；Steward Observatory, University of Arizona（亚利桑那大学斯图尔德天文台）；Jet Propulsion Laboratory, California Institute of Technology（加州理工学院喷气推进实验室）；Division of Geological and Planetary Sciences, California Institute of Technology（加州理工学院地质与行星科学系）；Astronomy Unit, Department of Physics and Astronomy, Queen Mary University of London（伦敦玛丽女王大学物理与天文学系天文学组）；Lunar and Planetary Laboratory, The University of Arizona（亚利桑那大学月球与行星实验室）；National Radio Astronomy Observatory（国家射电天文台）
We study the utility of the [OI] 6300$\mathring{\mathrm A}$ forbidden line for identifying and interpreting externally driven photoevaporative winds in different environments and at a range of distances. Thermally excited [OI] 6300$\mathring{\mathrm A}$ is a well known tracer of inner disc winds, so any external contribution needs to be distinguishable. In external winds, the line is not thermally excited and instead results from the dissociation of OH and we study how the line luminosity resulting from that process scales with the disc/environmental parameters. We find that the line luminosit…
(Abridged) We present the first radiation-hydrodynamic model of a protoplanetary disc irradiated with an X-EUV spectrum. In a model where the total ionizing luminosity is divided equally between X-ray and EUV luminosity, we find a photoevaporation rate of 1.4e-8 M_sun/yr, which is two orders of magnitude greater than the case of EUV photoevaporation alone. Thus it is clear that the X-rays are the dominant driving mechanism for photoevaporation. This can be understood inasmuch as X-rays are capable of penetrating much larger columns (~1e22 cm^-2) and can thus effect heating in denser regions an…
We present a study of the evolution of the inner few astronomical units of protoplanetary disks around low-mass stars. We consider nearby stellar groups with ages spanning from 1 to 11 Myr, distributed into four age bins. Combining PANSTARSS photometry with spectral types, we derive the reddening consistently for each star, which we use (1) to measure the excess emission above the photosphere with a new indicator of IR excess and (2) to estimate the mass accretion rate ($\dot{M}$) from the equivalent width of the H$α$ line. Using the observed decay of $\dot{M}$ as a constrain to fix the initia…
