C.D.S. - SIMBAD4 rel 1.7 - 2021.04.18CEST10:49:32

2017A&A...603A..96R - Astronomy and Astrophysics, volume 603A, 96-96 (2017/7-1)

Stellar energetic particle ionization in protoplanetary disks around T Tauri stars.


Abstract (from CDS):

Context. Anomalies in the abundance measurements of short lived radionuclides in meteorites indicate that the protosolar nebulae was irradiated by a large number of energetic particles (E≥10MeV). The particle flux of the contemporary Sun cannot explain these anomalies. However, similar to T Tauri stars the young Sun was more active and probably produced enough high energy particles to explain those anomalies.
Aims. We aim to study the interaction of stellar energetic particles with the gas component of the disk (i.e. ionization of molecular hydrogen) and identify possible observational tracers of this interaction.
Methods. We used a 2D radiation thermo-chemical protoplanetary disk code to model a disk representative for T Tauri stars. We used a particle energy distribution derived from solar flare observations and an enhanced stellar particle flux proposed for T Tauri stars. For this particle spectrum we calculated the stellar particle ionization rate throughout the disk with an accurate particle transport model. We studied the impact of stellar particles for models with varying X-ray and cosmic-ray ionization rates.
Results. We find that stellar particle ionization has a significant impact on the abundances of the common disk ionization tracers HCO+ and N2H+, especially in models with low cosmic-ray ionization rates (e.g. 10–19s–1 for molecular hydrogen). In contrast to cosmic rays and X-rays, stellar particles cannot reach the midplane of the disk. Therefore molecular ions residing in the disk surface layers are more affected by stellar particle ionization than molecular ions tracing the cold layers and midplane of the disk.
Conclusions. Spatially resolved observations of molecular ions tracing different vertical layers of the disk allow to disentangle the contribution of stellar particle ionization from other competing ionization sources. Modelling such observations with a model like the one presented here allows to constrain the stellar particle flux in disks around T Tauri stars.

Abstract Copyright: © ESO, 2017

Journal keyword(s): stars: formation - circumstellar matter - stars: activity - radiative transfer - astrochemistry - methods: numerical - methods: numerical

Simbad objects: 8

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Number of rows : 8

N Identifier Otype ICRS (J2000)
ICRS (J2000)
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2021
1 V* DM Tau Or* 04 33 48.7335659850 +18 10 09.974471722 14.30 14.82 14.00     M2Ve 538 0
2 V* GM Aur Or* 04 55 10.9813656049 +30 21 59.375978047 14.59 14.22 13.10     K3Ve 567 0
3 NAME Orion Nebula Cluster OpC 05 35.0 -05 29           ~ 2051 1
4 M 42 HII 05 35 17.3 -05 23 28           ~ 3787 0
5 V* V2457 Ori Or* 05 35 26.97000 -05 09 54.4644         18.858 ~ 125 0
6 OMC 2 MoC 05 35 27 -05 10.1           ~ 404 1
7 V* TW Hya TT* 11 01 51.9054298616 -34 42 17.031550898   11.94 10.50 10.626 9.18 K6Ve 1612 1
8 THA 15-12 Or* 15 56 09.2067120748 -37 56 06.126159332   13.12 11.93 11.45   M0e 280 0

    Equat.    Gal    SGal    Ecl

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