X-rays from jet-driving protostars and T Tauri stars

Abstract

(abridged:) We study X-rays from jet-driving protostars and T Tau stars. We seek soft spectral components that may be due to shock emission, and shock-induced emission displaced from the stellar position. Two stellar samples are used, the first consisting of lightly absorbed T Tau stars with strong jets, the other containing protostars with disks seen nearly edge-on. The former sample was observed in the XMM-Newton Extended Survey of the Taurus Molecular Cloud (XEST), while Chandra archival data provided observations of the latter. We confirm the previously identified peculiar spectrum of DG Tau A and find similar phenomenology in GV Tau and DP Tau, suggesting a new class of X-ray spectra. These consist of a lightly absorbed, very soft component and a strongly absorbed, very hard component. The latter is flaring while little variability is detected in the former. The absorption of the harder component is about an order of magnitude higher than expected from the optical extinction assuming a standard gas-to-dust mass ratio. The flaring hard component represents active coronal emission. Its strong absorption is attributed to mass inflow from the accretion disk. The optical extinction is small because the dust has sublimated at larger distances. The weakly absorbed soft component cannot originate from the same location. Because the stars drive strong jets, we propose that the X-rays are generated in shocks in the jets. We find that for the three peculiar X-ray sources, the luminosity of the soft component roughly scales with the equivalent width of the [OI] 6300A line formed in the jets, and with the mass outflow rate. In the more strongly obscured protostars, the soft component is entirely absorbed, and only the hard, coronal component penetrates the envelope or the near-edge-on disk.

17 pages, 27 figures, A&A style. Accepted by A&A, to appear in a special section/issue dedicated to the XMM-Newton Extended Survey of the Taurus Molecular Cloud (XEST). Version with higher resolution figures available at http://www.issibern.ch/teams/Taurus/papers.html or http://www.astro.phys.ethz.ch/papers/guedel/guedel_p_nf.html

References in corpus (41)

• The European Photon Imaging Camera on XMM-Newton: The MOS Cameras
• Circumstellar Dust Disks in Taurus-Auriga: The Submillimeter Perspective
• The XMM-Newton Optical/UV Monitor Telescope
• Accretion Disks around Young Objects. I. The Detailed Vertical Structure
• The Origin of T Tauri X-ray Emission: New Insights from the Chandra Orion Ultradeep Project
• Observational Constraints on the Formation and Evolution of Binary Stars
• Dynamical Masses of T Tauri Stars and Calibration of PMS Evolution
• X-ray astronomy of stellar coronae (Review)
• Evidence for Accretion: High-Resolution X-ray Spectroscopy of the Classical T Tauri Star TW Hydrae
• The XMM-Newton Extended Survey of the Taurus Molecular Cloud (XEST)
• On the Evolutionary Status of Class I Stars and Herbig-Haro Energy Sources in Taurus-Auriga
• X-Ray Flares and Mass Outflows Driven by Magnetic Interaction between a Protostar and its Surrounding Disk
• IRAC Observations of Taurus Pre-Main Sequence Stars
• HST/NICMOS Imaging of Disks and Envelopes Around Very Young Stars
• HST/STIS Spectroscopy of the Optical Outflow from DG Tau: Indications for Rotation in the Initial Jet Channel
• Determination of the gas-to-dust ratio in nearby dense clouds using X-ray absorption measurements
• New Brown Dwarfs and an Updated Initial Mass Function in Taurus
• Probing T Tauri Accretion and Outflow with 1 Micron Spectroscopy
• HST/STIS spectroscopy of the optical outflow from DG Tau: structure and kinematics on sub-arcsecond scales
• Coronal Evolution of the Sun in Time: High-Resolution X-Ray Spectroscopy of Solar Analogs with Different Ages
• Locating the Launching Region of T Tauri Winds: The Case of DG Tau
• X-ray emission from a metal depleted accretion shock onto the classical T Tauri star TW Hya
• He I 10830 as a Probe of Winds in Accreting Young Stars
• Optical Spectroscopy of Embedded Young Stars in the Taurus-Auriga Molecular Cloud
• A Hot Wind from the Classical T Tauri Stars: TW Hydrae and T Tauri
• Multi-epoch VLBA observations of T Tauri South
• The discovery of X-ray emission from the protostellar jet L1551 IRS5 (HH 154)
• Evidence for an X-Ray Jet in DG Tau A?
• The first high-resolution X-ray spectrum of a Herbig Star: The case of AB Aurigae
• The X-ray Luminosities of HH Objects
• X-ray Emission from Orion Nebula Cluster Stars with Circumstellar Disks and Jets
• HeI 1.083 micron emission and absorption in DG Tau: line excitation in jet, hot wind, and accretion flow
• A Deep Chandra X-ray Observation of the Embedded Young Cluster in NGC 2024
• X-rays from HH 80, HH 81, and the Central Region
• Classical T Tauri stars as sources of parsec-scale optical outflows
• A High-Resolution Very Large Array Observation of a Protostar in OMC-3: Shock-induced X-ray Emission by a Protostellar Jet
• The XMM-Newton Optical Monitor Survey of the Taurus Molecular Cloud
• 3-D numerical simulations of rotating jets: The case of the DG Tau microjet
• The near-infrared and ice-band variability of Haro 6-10
• X-rays from Cepheus A East and West
• The Enigmatic HH 255

Cited by in corpus (56)

• Photoevaporation of Circumstellar Disks by FUV, EUV and X-ray Radiation from the Central Star
• The XMM-Newton Extended Survey of the Taurus Molecular Cloud (XEST)
• X-Ray Spectroscopy of Stars
• TADPOL: A 1.3 mm Survey of Dust Polarization in Star-forming Cores and Regions
• Planetesimal formation by the streaming instability in a photoevaporating disk
• X-ray Emission from T Tauri Stars and the Role of Accretion: Inferences from the XMM-Newton Extended Survey of the Taurus Molecular Cloud
• A Deep Chandra X-ray Spectrum of the Accreting Young Star TW Hydrae
• Molecule survival in magnetized protostellar disk winds. I. Chemical model and first results
• Discovery of a bipolar X-ray jet from the T Tauri star DG Tau
• On the origin of [NeII] 12.81 micron emission from pre-main sequence stars: Disks, jets, and accretion
• X-rays from T Tau: A test case for accreting T Tauri stars
• Water vapor in the protoplanetary disk of DG Tau
• X-ray impact on the protoplanetary disks around T Tauri stars
• Testing Models of Accretion-driven Coronal Heating and Stellar Wind Acceleration for T Tauri Stars
• The X-ray soft excess in classical T Tauri stars
• Evidence for Accretion in the High-resolution X-ray Spectrum of the T Tauri Star System Hen 3-600
• Herschel/PACS observations of young sources in Taurus: the far-infrared counterpart of optical jets
• Coronae in the Coronet: A very deep X-ray look into a stellar nursery
• The interpretation of protoplanetary disc wind diagnostic lines from X-ray photoevaporation and analytical MHD models
• The nature of the soft X-ray source in DG Tau
• Further X-ray detections of Herbig stars
• The X-ray puzzle of the L1551 IRS 5 jet
• X-ray radiative transfer in protoplanetary disks - The role of dust and X-ray background fields
• Direct Measurement of Interstellar Extinction Toward Young Stars Using Atomic Hydrogen Lyman-$\alpha$ Absorption
• Radio continuum emission from knots in the DG Tau jet
• Multi-epoch Sub-arcsecond [Fe II] Spectroimaging of the DG Tau Outflows with NIFS. I. First data epoch
• Revealing the fastest component of the DG Tau outflow through X-rays
• The XMM-Newton Optical Monitor Survey of the Taurus Molecular Cloud
• Results from DROXO. III. Observation, source list and X-ray properties of sources detected in the "Deep Rho Ophiuchi XMM-Newton Observation"
• The X-ray activity-rotation relation of T Tauri stars in Taurus-Auriga
• HST FUV imaging of DG Tau: Fluorescent molecular hydrogen emission from the wide angle outflow
• Testing the models of X-ray driven photoevaporation with accreting stars in the Orion Nebula Cluster
• HST FUV C IV observations of the hot DG Tauri jet
• A few days before the end of the 2008 extreme outburst of EX Lup : accretion shocks and a smothered stellar corona unveiled by XMM-Newton
• Chandra Reveals Variable Multi-Component X-ray Emission from FU Orionis
• VLA Observations of DG Tau's Radio Jet: A highly collimated thermal outflow
• Sub-arcsecond high sensitivity measurements of the DG~Tau jet with e-MERLIN
• X-ray deficiency on strong accreting T Tauri stars - Comparing Orion with Taurus
• Unbinned maximum-likelihood estimators for low-count data: Applications to faint X-ray spectra in the Taurus Molecular Cloud
• X-rays from young stars - a summary of highlights from the XMM-Newton Extended Survey of the Taurus Molecular Cloud (XEST)
• Velocity-Resolved [Ne III] from X-Ray Irradiated Sz 102 Microjets
• Probing the gaseous disk of T Tau N with CN 5-4 lines
• Study of the bipolar jet of the YSO Th 28 with VLT/SINFONI: Jet morphology and H${}_2$ emission
• A Theoretical Model of X-ray Jets from Young Stellar Objects
• Revealing Ionization Conditions of Sz 102 with Spatially Resolved [Ne III] Microjets
• X-ray variability of cool stars: Magnetic activity and accretion
• RW Aur A : SpeX Spectral Evidence for Differentiated Planetesimal Formation, Migration and Destruction in an 3 Myr Old Excited CTTS System
• Chandra X-ray Detection of the Enigmatic Field Star BP Psc
• Pre main sequence: Accretion & Outflows
• Imaging of HH80-81 jet in the NIR shock tracers H${}_2$ and [Fe II]
• On the diversification and dissipation of protoplanetary disks
• The Bipolar X-Ray Jet of the Classical T Tauri Star DG Tau
• Evidence for protostellar jets as a population of hadronic gamma-ray sources
• Accretion discs, low-mass protostars and planets: probing the impact of magnetic fields on stellar formation
• Dust in the wind of outbursting young stars
• Young Stars in the Time Domain: A Cool Stars 16 Splinter Summary