TY - JOUR
T1 - Why are accreting T Tauri stars observed to be less luminous in X-rays than non-accretors?
AU - Gregory, S. G.
AU - Wood, K.
AU - Jardine, M.
PY - 2007/7/1
Y1 - 2007/7/1
N2 - Accreting T Tauri stars are observed to be less luminous in X-rays than non-accretors, an effect that has been detected in various star-forming regions. To explain this we have combined, for the first time, a radiative transfer code with an accretion model that considers magnetic fields extrapolated from surface magnetograms obtained from Zeeman-Doppler imaging. Such fields consist of compact magnetic regions close to the stellar surface, with extended field lines interacting with the disc. We study the propagation of coronal X-rays through the magnetosphere and demonstrate that they are strongly absorbed by the dense gas in accretion columns. The reduction in the observed X-ray emission depends on the field geometry, which may explain why accreting T Tauri stars show a larger scatter in their observed X-ray luminosity compared with non-accreting stars.
AB - Accreting T Tauri stars are observed to be less luminous in X-rays than non-accretors, an effect that has been detected in various star-forming regions. To explain this we have combined, for the first time, a radiative transfer code with an accretion model that considers magnetic fields extrapolated from surface magnetograms obtained from Zeeman-Doppler imaging. Such fields consist of compact magnetic regions close to the stellar surface, with extended field lines interacting with the disc. We study the propagation of coronal X-rays through the magnetosphere and demonstrate that they are strongly absorbed by the dense gas in accretion columns. The reduction in the observed X-ray emission depends on the field geometry, which may explain why accreting T Tauri stars show a larger scatter in their observed X-ray luminosity compared with non-accreting stars.
KW - Stars: activity
KW - stars: coronae
KW - stars: magnetic fields
KW - Stars: pre-main-sequence
KW - X-rays: stars
UR - https://arxiv.org/abs/0704.2958
UR - https://ui.adsabs.harvard.edu/abs/2007MNRAS.379L..35G/abstract
U2 - 10.1111/j.1745-3933.2007.00328.x
DO - 10.1111/j.1745-3933.2007.00328.x
M3 - Article
VL - 379
SP - L35-L39
JO - Monthly Notices of the Royal Astronomical Society: Letters
JF - Monthly Notices of the Royal Astronomical Society: Letters
SN - 1745-3925
IS - 1
ER -