The X-ray puzzle of the L1551 IRS 5 jet

Abstract

Protostars are actively accreting matter and they drive spectacular, dynamic outflows, which evolve on timescales of years. X-ray emission from these jets has been detected only in a few cases and little is known about its time evolution. We present a new Chandra observation of L1551 IRS 5's jet in the context of all available X-ray data of this object. Specifically, we perform a spatially resolved spectral analysis of the X-ray emission and find that (a) the total X-ray luminosity is constant over almost one decade, (b) the majority of the X-rays appear to be always located close to the driving source, (c) there is a clear trend in the photon energy as a function of the distance to the driving source indicating that the plasma is cooler at larger distances and (d) the X-ray emission is located in a small volume which is unresolved perpendicular to the jet axis by Chandra. A comparison of our X-ray data of the L1551 IRS 5 jet both with models as well as X-ray observations of other protostellar jets shows that a base/standing shock is a likely and plausible explanation for the apparent constancy of the observed X-ray emission. Internal shocks are also consistent with the observed morphology if the supply of jet material by the ejection of new blobs is sufficiently constant. We conclude that the study of the X-ray emission of protostellar jet sources allows us to diagnose the innermost regions close to the acceleration region of the outflows.

A&A accepted, 14 pages, 9 figures

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Cited by in corpus (24)

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• Resolving the Inner Arcsecond of the RY Tau Jet With HST
• HST FUV C IV observations of the hot DG Tauri jet
• A New Diagnostic of Magnetic Field Strengths in Radiatively-Cooled Shocks
• The evolution of the jet from Herbig Ae star HD 163296 from 1999 to 2011
• A Comparison of the X-ray Properties of FU Ori-type Stars to Generic Young Stellar Objects
• The UV Perspective of Low-Mass Star Formation
• Multiepoch, multiwavelength study of accretion onto T Tauri: X-ray versus optical and UV accretion tracers
• Time-Variable Jet Ejections from RW Aur A, RY Tau and DG Tau
• Recollimation boundary layers as X-ray sources in young stellar jets
• Formation of X-ray emitting stationary shocks in magnetized protostellar jets
• Herschel Key Program, "Dust, Ice, and Gas In Time" (DIGIT): the origin of molecular and atomic emission in low-mass protostars in Taurus
• VLA Observations of DG Tau's Radio Jet: A highly collimated thermal outflow
• Velocity asymmetries in YSO jets: Intrinsic and extrinsic mechanisms
• Spitzer observations of Bow Shocks and Outflows in RCW 38
• Structure of X-ray emitting jets close to the launching site: from embedded to disk-bearing sources
• A Theoretical Model of X-ray Jets from Young Stellar Objects
• Chandra Resolves the Double FU Orionis System RNO 1B/1C in X-rays
• The evolution of the X-ray emission of HH 2 - Investigating heating and cooling processes
• Monitoring inner regions in the RY Tau jet
• Pre main sequence: Accretion & Outflows
• Variability of young stellar objects: accretion, disks, outflows and magnetic activity