Photoevaporation of protoplanetary discs – II. Evolutionary models and observable properties

Alexander, R. D.; Clarke, C. J.; Pringle, J. E.

doi:10.1111/j.1365-2966.2006.10294.x

Cited by 470 publications

(469 citation statements)

References 52 publications

(131 reference statements)

Supporting

Mentioning

442

Contrasting

Order By: Relevance

“…68. Numerical simulations confirm this behavior and suggest that at the end of the disk lifetime (several Myr), the disk rapidly disperses within ∼ > 10 5 yr (Alexander et al 2006b). EUV (Ly continuum) radiation is problematic because it may not reach the disk at all if disk winds absorb them early on.…”

Section: Epj Web Of Conferencesmentioning

confidence: 67%

Ionization and heating by X-rays and cosmic rays

Güdel

2015

EPJ Web of Conferences

View full text Add to dashboard Cite

Abstract. High-energy radiation from the central T Tauri and protostars plays an important role in shaping protoplanetary disks and influences their evolution. Such radiation, in particular X-rays and extreme-ultraviolet (EUV) radiation, is predominantly generated in unstable stellar magnetic fields (e.g., the stellar corona), but also in accretion hot spots. Even jets may produce X-ray emission. Cosmic rays, i.e., high-energy particles either from the interstellar space or from the star itself, are of crucial importance. Both highenergy photons and particles ionize disk gas and lead to heating. Ionization and heating subsequently drive chemical networks, and the products of these processes are accessible through observations of molecular line emission. Furthermore, ionization supports the magnetorotational instability and therefore drives disk accretion, while heating of the disk surface layers induces photoevaporative flows. Both processes are crucial for the dispersal of protoplanetary disks and therefore critical for the time scales of planet formation. This chapter introduces the basic physics of ionization and heating starting from a quantum mechanical viewpoint, then discusses relevant processes in astrophysical gases and their applications to protoplanetary disks, and finally summarizes some properties of the most important high-energy sources for protoplanetary disks.

show abstract

Section: Epj Web Of Conferencesmentioning

confidence: 67%

Ionization and heating by X-rays and cosmic rays

Güdel

2015

EPJ Web of Conferences

View full text Add to dashboard Cite

show abstract

“…Recent detection of [Ne II] emission lines Herczeg et al 2007;Najita et al 2009) has been interpreted as evidence for irradiation of the disc's atmosphere by energetic photons (extreme ultraviolet or X-ray) and possibly associated photoevaporation (Alexander et al 2006b;Pascucci et al 2007). presented a self-consistent hydrodynamic model of an X-EUV driven photoevaporation wind, obtaining mass-loss rates of 1.4×10 −8 M yr −1 occurring over a large radial extent of 1-70 AU.…”

Section: X-ray Photoevaporationmentioning

confidence: 99%

“…Kenyon & Hartmann 1995;Luhman et al 2010;. Such observed twotimescale behaviour has favoured the development of disc dispersal models that involve a rapid disc clearing phase, contrary to the predictions of simple viscous draining, and in agreement with photoevaporation (Clarke et al 2001;Alexander et al 2006a;Alexander et al 2006b;Ercolano 2008;Ercolano et al 2009;Gorti et al 2009;Owen et al 2010;Owen et al 2011b;Owen et al 2012) or possibly planet formation (Armitage & Hansen 1999).…”

Section: Introductionmentioning

confidence: 98%

The dispersal of protoplanetary discs

Ercolano

2014

Astron Nachr

View full text Add to dashboard Cite

Protoplanetary discs are a natural consequence of the star formation process and as such are ubiquitous around low-mass stars. They are fundamental to planet formation as they hold the reservoir of material from which planets form. Their evolution and final dispersal and the timescales that regulate these process are therefore of particular interest. In this contribution I will review the observational evidence for the dispersal of discs being dominated by two timescales and for the final dispersal to occur quickly and from the inside out. I will discuss the current theoretical models, including X-ray photoevaporation, showing that the latter provides a natural explanation to the observed behaviour and review supporting and contrasting evidence. I will finally introduce a new mechanism based on the interaction between planet formation and photoevaporation that may explain a particular class of transition discs with large inner holes and high accretion rates that are problematic for photoevaporation models and planet formation models alone.

show abstract

“…Models that produce an inside-out dispersal of disks include the effects of photoevaporation by stellar X-ray and UV radiation (e.g., Alexander et al 2006;Gorti & Hollenbach 2009;Owen et al 2010). In these models, disk gaps are opened where thermal heating launches the gas into a photoevaporative wind by providing enough energy to exceed the gravitational potential of the star.…”

Section: Introductionmentioning

confidence: 99%

The Depletion of Water During Dispersal of Planet-Forming Disk Regions

Banzatti

Pontoppidan

Salyk

et al. 2017

ApJ

121

View full text Add to dashboard Cite

We present a new velocity-resolved survey of 2.9 μm spectra of hot H 2 O and OH gas emission from protoplanetary disks, obtained with the Cryogenic Infrared Echelle Spectrometer at the VLT (R ∼ 96,000). With the addition of archival Spitzer-IRS spectra, this is the most comprehensive spectral data set of water vapor emission from disks ever assembled. We provide line fluxes at 2.9-33 μm that probe from the dust sublimation radius at ∼0.05 au out to the region of the water snow line. With a combined data set for 55 disks, we find a new correlation between H 2 O line fluxes and the radius of CO gas emission, as measured in velocity-resolved 4.7 μm spectra (Rco), which probes molecular gaps in inner disks. We find that H 2 O emission disappears from 2.9 μm (hotter water) to 33 μm (colder water) as R co increases and expands out to the snow line radius. These results suggest that the infrared water spectrum is a tracer of inside-out water depletion within the snow line. It also helps clarify an unsolved discrepancy between water observations and models by finding that disks around stars ofgenerally have inner gaps with depleted molecular gas content. We measure radial trends in H 2 O, OH, and CO line fluxes that can be used as benchmarks for models to study the chemical composition and evolution of planet-forming disk regions at 0.05-20 au. We propose that JWST spectroscopy of molecular gas may be used as a probe of inner disk gas depletion, complementary to the larger gaps and holes detected by direct imaging and by ALMA.

show abstract

Photoevaporation of protoplanetary discs – II. Evolutionary models and observable properties

Cited by 470 publications

References 52 publications

Ionization and heating by X-rays and cosmic rays

Ionization and heating by X-rays and cosmic rays

The dispersal of protoplanetary discs

The Depletion of Water During Dispersal of Planet-Forming Disk Regions

Contact Info

Product

Resources

About