Chandra and XMM-Newton X-ray Observations of the Hyperactive T Tauri Star RY Tau

Abstract

We present results of pointed X-ray observations of the accreting jet-driving T Tauri star RY Tau using Chandra and XMM-Newton. We obtained high-resolution grating spectra and excellent-quality CCD spectra and light curves with the objective of identifying the physical mechanisms underlying RY Tau's bright X-ray emission. Grating spectra reveal numerous emission lines spanning a broad range of temperature superimposed on a hot continuum. The X-ray emission measure distribution is dominated by very hot plasma at T_hot ~ 50 MK but higher temperatures were present during flares. A weaker cool plasma component is also present as revealed by low-temperature lines such as O VIII. X-ray light curves show complex variability consisting of short-duration (~hours) superhot flares accompanied by fluorescent Fe emission at 6.4 keV superimposed on a slowly-varying (~one day) component that may be tied to stellar rotation. The hot flaring component is undoubtedly of magnetic (e.g. coronal) origin. Soft and hard-band light curves undergo similar slow variability implying that at least some of the cool plasma shares a common magnetic origin with the hot plasma. Any contribution to the X-ray emission from cool shocked plasma is small compared to the dominant hot component but production of individual low-temperature lines such as O VIII in an accretion shock is not ruled out.

41 pages, 8 figures, 6 tables

References in corpus (11)

• The Magnetic Fields of Classical T Tauri Stars
• The XMM-Newton Extended Survey of the Taurus Molecular Cloud (XEST)
• X-ray Emission from T Tauri Stars and the Role of Accretion: Inferences from the XMM-Newton Extended Survey of the Taurus Molecular Cloud
• Discovery of a bipolar X-ray jet from the T Tauri star DG Tau
• X-rays from T Tau: A test case for accreting T Tauri stars
• High Resolution X-ray Spectroscopy of T Tauri Stars in the Taurus-Auriga Complex
• The T Tauri star RY Tau as a case study of the inner regions of circumstellar dust disks
• The discovery of an expanding X-ray source in the HH 154 protostellar jet
• Chandra and Spitzer Imaging of the Infrared Cluster in NGC 2071
• Hard X-rays and Fluorescent Iron Emission from the Embedded Infrared Cluster in NGC 2071
• X-rays from HH210 in the Orion nebula

Cited by in corpus (9)

• What happened before? -- The disks around the precursors of young Herbig Ae/Be stars
• Resolving the Inner Arcsecond of the RY Tau Jet With HST
• Intriguing X-ray and optical variations of the gamma Cas analog HD45314
• Dynamics of wind and the dusty environments in the accreting T Tauri stars RY Tau and SU Aur
• Fluorescent Fe K line emission of gamma Cas stars I. Do gamma Cas stars host propelling neutron stars?
• Disk Evolution Study Through Imaging of Nearby Young Stars (DESTINYS): Scattered light detection of a possible disk wind in RY Tau
• A Theoretical Model of X-ray Jets from Young Stellar Objects
• On the source of the Fe K-alpha emission in T Tauri Stars. Radiation induced by relativistic electrons during flares. An application to RY Tau
• The MATISSE view of the inner region of the RY Tau protoplanetary disk