X-rays from accretion shocks in classical T Tauri stars: 2D MHD modeling and the role of local absorption

Giovanni Peres, Fabio Reale, Rosaria Bonito, Costanza Argiroffi, Marco Miceli, Matsakos, Ibgui, Sthelé, Argiroffi, Fabio Reale, Orlando, Giovanni Peres, Miceli

Risultato della ricerca: Other

Abstract

In classical T Tauri stars (CTTS) strong shocks are formed where the accretion funnel impacts with the denser stellar chromosphere. Although current models of accretion provide a plausible global picture of this process, some fundamental aspects are still unclear: the observed X-ray luminosity in accretion shocks is order of magnitudes lower than predicted; the observed density and temperature structures of the hot post-shock region are puzzling and still unexplained by models. To address these issues we performed 2D MHD simulations describing an accretion stream impacting onto the chromosphere of a CTTS, exploring different configurations and strengths of the magnetic field. From the model results we then synthesized the X-ray emission emerging from the hot post-shock, taking into account the local absorption due to the pre-shock stream and surrounding atmosphere. We find that the different configurations and strengths of the magnetic field profoundly affect the hot post-shock properties. Moreover the emerging X-ray emission strongly depends also on the viewing angle under which accretion is observed. Some of the explored configuration are able to reproduce the observed features of X-ray spectra of CTTS. © International Astronomical Union 2014.
Lingua originaleEnglish
Numero di pagine2
Stato di pubblicazionePublished - 2014

Fingerprint

T Tauri stars
Shock
shock
accretion
X-Rays
modeling
x rays
chromosphere
Magnetic Fields
emerging
magnetic field
configurations
funnels
Atmosphere
magnetic fields
Hot Temperature
luminosity
atmosphere
atmospheres
simulation

All Science Journal Classification (ASJC) codes

  • Medicine (miscellaneous)
  • Astronomy and Astrophysics
  • Nutrition and Dietetics
  • Public Health, Environmental and Occupational Health
  • Space and Planetary Science

Cita questo

@conference{90b78e621770485884bf198d477df00e,
title = "X-rays from accretion shocks in classical T Tauri stars: 2D MHD modeling and the role of local absorption",
abstract = "In classical T Tauri stars (CTTS) strong shocks are formed where the accretion funnel impacts with the denser stellar chromosphere. Although current models of accretion provide a plausible global picture of this process, some fundamental aspects are still unclear: the observed X-ray luminosity in accretion shocks is order of magnitudes lower than predicted; the observed density and temperature structures of the hot post-shock region are puzzling and still unexplained by models. To address these issues we performed 2D MHD simulations describing an accretion stream impacting onto the chromosphere of a CTTS, exploring different configurations and strengths of the magnetic field. From the model results we then synthesized the X-ray emission emerging from the hot post-shock, taking into account the local absorption due to the pre-shock stream and surrounding atmosphere. We find that the different configurations and strengths of the magnetic field profoundly affect the hot post-shock properties. Moreover the emerging X-ray emission strongly depends also on the viewing angle under which accretion is observed. Some of the explored configuration are able to reproduce the observed features of X-ray spectra of CTTS. {\circledC} International Astronomical Union 2014.",
author = "Giovanni Peres and Fabio Reale and Rosaria Bonito and Costanza Argiroffi and Marco Miceli and Matsakos and Ibgui and Sthel{\'e} and Argiroffi and Fabio Reale and Orlando and Giovanni Peres and Miceli",
year = "2014",
language = "English",

}

TY - CONF

T1 - X-rays from accretion shocks in classical T Tauri stars: 2D MHD modeling and the role of local absorption

AU - Peres, Giovanni

AU - Reale, Fabio

AU - Bonito, Rosaria

AU - Argiroffi, Costanza

AU - Miceli, Marco

AU - Matsakos, null

AU - Ibgui, null

AU - Sthelé, null

AU - Argiroffi, null

AU - Reale, Fabio

AU - Orlando, null

AU - Peres, Giovanni

AU - Miceli, null

PY - 2014

Y1 - 2014

N2 - In classical T Tauri stars (CTTS) strong shocks are formed where the accretion funnel impacts with the denser stellar chromosphere. Although current models of accretion provide a plausible global picture of this process, some fundamental aspects are still unclear: the observed X-ray luminosity in accretion shocks is order of magnitudes lower than predicted; the observed density and temperature structures of the hot post-shock region are puzzling and still unexplained by models. To address these issues we performed 2D MHD simulations describing an accretion stream impacting onto the chromosphere of a CTTS, exploring different configurations and strengths of the magnetic field. From the model results we then synthesized the X-ray emission emerging from the hot post-shock, taking into account the local absorption due to the pre-shock stream and surrounding atmosphere. We find that the different configurations and strengths of the magnetic field profoundly affect the hot post-shock properties. Moreover the emerging X-ray emission strongly depends also on the viewing angle under which accretion is observed. Some of the explored configuration are able to reproduce the observed features of X-ray spectra of CTTS. © International Astronomical Union 2014.

AB - In classical T Tauri stars (CTTS) strong shocks are formed where the accretion funnel impacts with the denser stellar chromosphere. Although current models of accretion provide a plausible global picture of this process, some fundamental aspects are still unclear: the observed X-ray luminosity in accretion shocks is order of magnitudes lower than predicted; the observed density and temperature structures of the hot post-shock region are puzzling and still unexplained by models. To address these issues we performed 2D MHD simulations describing an accretion stream impacting onto the chromosphere of a CTTS, exploring different configurations and strengths of the magnetic field. From the model results we then synthesized the X-ray emission emerging from the hot post-shock, taking into account the local absorption due to the pre-shock stream and surrounding atmosphere. We find that the different configurations and strengths of the magnetic field profoundly affect the hot post-shock properties. Moreover the emerging X-ray emission strongly depends also on the viewing angle under which accretion is observed. Some of the explored configuration are able to reproduce the observed features of X-ray spectra of CTTS. © International Astronomical Union 2014.

UR - http://hdl.handle.net/10447/100681

UR - https://www.cambridge.org/core/journals/proceedings-of-the-international-astronomical-union/article/xrays-from-accretion-shocks-in-classical-t-tauri-stars-2d-mhd-modeling-and-the-role-of-local-absorption/3C9CE54272FDB2EB4FF3DA5C365AF925

M3 - Other

ER -