Spatially-resolved Chandra Imaging Spectroscopy of the classical/weak-lined T Tauri system V710 Tau

TL;DR

This study uses Chandra X-ray imaging to resolve and analyze the individual X-ray properties of the binary T Tauri star system V710 Tau, revealing differences in their emission states and plasma characteristics.

Contribution

First spatially-resolved X-ray spectral and temporal analysis of the classical/weak-lined T Tauri binary V710 Tau, demonstrating distinct emission behaviors of each component.

Findings

V710 Tau N was in a flaring state during the first observation.

V710 Tau S's X-ray spectra are well-fit by plasma models with temperatures 0.7-1.1 keV.

V710 Tau N showed a higher-temperature plasma component during the flare.

Abstract

We present spatially-resolved X-ray observations of the binary T Tauri star system V710 Tau. Using Chandra's Advanced CCD Imaging Spectrometer (ACIS), we imaged this 3.2'' separation binary system, consisting of a classical T Tauri star, V710 Tau N, and a weak-lined T Tauri star, V710 Tau S. The Chandra ACIS-S3 images -- obtained in two 9 ks exposures separated by about three months (2004 December and 2005 April) -- cleanly resolve the V710 Tau binary, demonstrating that both stars emit X-rays and thereby enabling the first spectral/temporal study of the individual components of this mixed (classical and weak-lined) T Tauri star binary system. The northern component, V710 Tau N, appears to have been in a flaring state during the first (2004 December) exposure. During this flare event, the X-ray flux of the classical T Tauri star hardened significantly. Single-component plasma models with plasma temperatures in the range kT ~ 0.7-1.1 keV are adequate to fit the observed X-ray spectra of V710 Tau S in 2004 December and both stars in 2005 April. The 2004 December flare-state observation of V710 Tau N requires a higher-temperature plasma component (kT ~ 2.5 - 3.0 keV) in addition to the soft component (kT ~ 0.5 keV) and is better fit by a model that includes a slightly enhanced Ne/Fe abundance ratio. These results are generally consistent with statistical contrasts between the X-ray emission properties of classical (rapidly accreting) vs. weak-lined (weakly accreting or non-accreting) T Tauri stars.