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The effects of X-ray photoionization and heating on the structure of circumstellar discs
| Content Provider | Semantic Scholar |
|---|---|
| Copyright Year | 2004 |
| Abstract | We present the results of a theoretical study investigating the effects of photoionization and heating by X-rays on discs around low-mass stars. In particular we address the question of whether or not X-rays can drive a disc wind. First, we construct a 1-dimensional “quasi-hydrostatic” model, which solves for the vertical structure introduced by X-ray heating. We consider uniform X-ray illumination of the disc, but the X-ray fluxes required to heat the disc significantly are much greater than those seen by recent observations. When the model is extended to consider heating from a central X-ray source we find that the 1-dimensional model is only valid very close to the star. We extend our analysis to consider a simple 2-dimensional model, treating the disc as a two-layered structure and solving for its density profile self-consistently. For T Tauri stars we are able to set a crude upper limit on the mass-loss rate that can be driven by X-ray photoevaporation, with a value of ≃ 10g cm s. Our model is designed to maximise this value, and most likely over-estimates it significantly. However we still find a mass-loss rate which is less than that found in studies of ultraviolet photoevaporation. We conclude that in the presence of a significant UV field, X-ray driven disc winds are unlikely to play a significant role in the evolution of discs around low-mass stars. |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://arxiv.org/pdf/astro-ph/0406643v1.pdf |
| Alternate Webpage(s) | http://cds.cern.ch/record/748393/files/0406643.pdf |
| Alternate Webpage(s) | https://www.astro.le.ac.uk/~rda5/xrays.pdf |
| Language | English |
| Access Restriction | Open |
| Subject Keyword | ABRA gene Anisotropic band Diagnostic radiologic examination Environmental Wind Estimated GUCY2C protein, human Heating Less Than Photoelectrochemical process Population Parameter Radiation Rajiformes Simulation Stars, Celestial UV mapping Views:Finding:Point in time:To be specified in another part of the message:Narrative:XR X-Ray (Amazon Kindle) anatomical layer hearing impairment |
| Content Type | Text |
| Resource Type | Article |
