Protoplanetary disc evolution and dispersal: the implications of X-ray photoevaportion

Details Protoplanetary disc evolution and dispersal: the implications of X-ray photoevaportion Protoplanetary disc evolution and dispersal: the implications of X-ray photoevaportion

2010-10-05

arxiv.org/abs/1010.0826v1

Astronomy and Astrophysics

Astrophysics

Solar and Stellar Astrophysics

15 Pages, 15 Figures, accepted for publication in MNRAS

Scientific paper

(Abridged) We explore the role of X-ray photoevaporation in the evolution and dispersal of viscously evolving T-Tauri discs. We show that the X-ray photoevaporation wind rates scale linearly with X-ray luminosity, such that the observed range of X-ray luminosities for solar-type T-Tauri stars (10e28-10e31 erg\s) gives rise to vigorous disc winds with rates of order 10e-10-10e-7 M_sun/yr. We use the wind solutions from radiation-hydrodynamic models, coupled to a viscous evolution model to construct a population synthesis model so that we may study the physical properties of evolving discs and so-called `transition discs'. Current observations of disc lifetimes and accretion rates can be matched by our model assuming a viscosity parameter alpha = 2.5e-3. Our models confirm that X-rays play a dominant role in the evolution and dispersal of protoplanetary discs giving rise to the observed diverse population of inner hole `transition' sources which include those with massive outer discs, those with gas in their inner holes and those with detectable accretion signatures. To help understand the nature of observed transition discs we present a diagnostic diagram based on accretion rates versus inner hole sizes that demonstrate that, contrary to recent claims, many of the observed accreting and non accreting transition discs can easily be explained by X-ray photoevaporation. Finally, we confirm the conjecture of Drake et al. (2009), that accretion is suppressed by the X-rays through `photoevaporation starved accretion' and predict this effect can give rise to a negative correlation between X-ray luminosity and accretion rate, as reported in the Orion data.

Affiliated with

Also associated with

No associations

Rating

Protoplanetary disc evolution and dispersal: the implications of X-ray photoevaportion does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Protoplanetary disc evolution and dispersal: the implications of X-ray photoevaportion, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Protoplanetary disc evolution and dispersal: the implications of X-ray photoevaportion will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-86446