2019A&A...630A..84D


Query : 2019A&A...630A..84D

2019A&A...630A..84D - Astronomy and Astrophysics, volume 630A, 84-84 (2019/10-1)

New insight on accretion shocks onto young stellar objects. Chromospheric feedback and radiation transfer.

DE SA L., CHIEZE J.-P., STEHLE C., HUBENY I., LANZ T. and CAYATTE V.

Abstract (from CDS):


Context. Material accreted onto classical T Tauri stars is expected to form a hot quasi-periodic plasma structure that radiates in X-rays. Simulations of this phenomenon only partly match observations. They all rely on a static model for the chromosphere and on the assumption that radiation and matter are decoupled.
Aims. We explore the effects of a shock-heated chromosphere and of the coupling between radiation and hydrodynamics on the structure and dynamics of the accretion flow.
Methods. We simulated accretion columns that fall onto a stellar chromosphere using the 1D ALE code AstroLabE. This code solves the hydrodynamics equations along with the first two moment equations for radiation transfer, with the help of a dedicated opacity table for the coupling between matter and radiation. We derive the total electron and ion densities from collisional-radiative model.
Results. The chromospheric acoustic heating affects the duration of the cycle and the structure of the heated slab. In addition, the coupling between radiation and hydrodynamics leads to a heating of the accretion flow and of the chromosphere: the whole column is pushed up by the inflating chromosphere over several times the steady chromosphere thickness. These last two conclusions are in agreement with the computed monochromatic intensity. Acoustic heating and radiation coupling affect the amplitude and temporal variations of the net X-ray luminosity, which varies between 30 and 94% of the incoming mechanical energy flux, depending on which model is considered.

Abstract Copyright: © L. de Sá et al. 2019

Journal keyword(s): stars: pre-main sequence - accretion, accretion disks - methods: numerical - hydrodynamics - radiative transfer - opacity

Simbad objects: 6

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Number of rows : 6
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2022
#notes
1 V* BP Tau Or* 04 19 15.8342975037 +29 06 26.929456808   13.13 12.12 11.89   K5/7Ve 625 0
2 V* TW Hya TT* 11 01 51.9054298616 -34 42 17.031550898   11.94 10.50 10.626 9.18 K6Ve 1675 1
3 TWA 3 ** 11 10 27.894072 -37 31 51.96612   13.53 12.05 11.61 9.29 M4Ve+M4Ve 205 0
4 CPD-68 1894 TT* 13 22 07.5420267499 -69 38 12.216304202   11.38 10.393   9.117 K1Ve 140 0
5 V* RU Lup Or* 15 56 42.3109948086 -37 49 15.473469159 9.27 10.07 9.60     K7/M0e 411 0
6 HD 319139 LM* 18 14 10.4818974563 -32 47 34.516106830   11.47 10.68   9.11 K5+K7 314 0

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2021.12.07-21:41:04

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