Spatially resolved magnetic field structure in the disk of a T Tauri star

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Abstract

Magnetic fields in accretion disks play a dominant part during the star formation process1,2 but have hitherto been observationally poorly constrained. Field strengths have been inferred on T Tauri stars3 and possibly in the innermost part of their accretion disks4, but the strength and morphology of the field in the bulk of a disk have not been observed. Spatially unresolved measurements of polarized emission (arising from elongated dust grains aligned perpendicularly to the field5) imply average fields aligned with the disks6,7. Theoretically, the fields are expected to be largely toroidal, poloidal or a mixture of the two1,2,8,9,10, which imply different mechanisms for transporting angular momentum in the disks of actively accreting young stars such as HL Tau (ref. 11). Here we report resolved measurements of the polarized 1.25-millimetre continuum emission from the disk of HL Tau. The magnetic field on a scale of 80 astronomical units is coincident with the major axis (about 210 astronomical units long12) of the disk. From this we conclude that the magnetic field inside the disk at this scale cannot be dominated by a vertical component, though a purely toroidal field also does not fit the data well. The unexpected morphology suggests that the role of the magnetic field in the accretion of a T Tauri star is more complex than our current theoretical understanding.

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Figure 1: Detected magnetic field morphology of HL Tau at 0.6″ resolution.
Figure 2: Observed magnetic field morphology compared with models.

References

  1. 1

    Blandford, R. D. & Payne, D. G. Hydromagnetic flows from accretion discs and the production of radio jets. Mon. Not. R. Astron. Soc. 199, 883–903 (1982)

    ADS  Article  Google Scholar 

  2. 2

    Balbus, S. A. & Hawley, J. F. Instability, turbulence, and enhanced transport in accretion disks. Rev. Mod. Phys. 70, 1–53 (1998)

    ADS  Article  Google Scholar 

  3. 3

    Johns-Krull, C. M. The magnetic fields of classical T Tauri stars. Astrophys. J. 664, 975–985 (2007)

    ADS  CAS  Article  Google Scholar 

  4. 4

    Donati, J.-F., Paletou, F., Bouvier, J. & Ferreira, J. Direct detection of a magnetic field in the innermost regions of an accretion disk. Nature 438, 466–469 (2005)

    ADS  CAS  Article  Google Scholar 

  5. 5

    Lazarian, A. Tracing magnetic fields with aligned grains. J. Quant. Spectrosc. Radiat. Transf. 106, 225–256 (2007)

    ADS  CAS  Article  Google Scholar 

  6. 6

    Tamura, M., Hough, J. H. & Hayashi, S. S. 1 millimeter polarimetry of young stellar objects: low-mass protostars and T Tauri stars. Astrophys. J. 448, 346–355 (1995)

    ADS  Article  Google Scholar 

  7. 7

    Tamura, M. et al. First detection of submillimeter polarization from T Tauri stars. Astrophys. J. 525, 832–836 (1999)

    ADS  Article  Google Scholar 

  8. 8

    Cho, J. & Lazarian, A. Grain alignment and polarized emission from magnetized T Tauri disks. Astrophys. J. 669, 1085–1097 (2007)

    ADS  CAS  Article  Google Scholar 

  9. 9

    Königl, A. & Pudritz, R. E. in Protostars and Planets IV (eds Mannings, V., Boss, A. P. & Russell, S. S. ) 759–787 (Univ. Arizona Press, 2000)

    Google Scholar 

  10. 10

    Hennebelle, P. & Ciardi, A. Disk formation during collapse of magnetized protostellar cores. Astron. Astrophys. 506, L29–L32 (2009)

    ADS  Article  Google Scholar 

  11. 11

    Robitaille, T. P., Whitney, B. A., Indebetouw, R. & Wood, K. Interpreting spectral energy distributions from young stellar objects. II. Fitting observed SEDs using a large grid of precomputed models. Astrophys. J. Suppl. Ser. 169, 328–352 (2007)

    ADS  Article  Google Scholar 

  12. 12

    Kwon, W., Looney, L. W. & Mundy, L. G. Resolving the circumstellar disk of HL Tauri at millimeter wavelengths. Astrophys. J. 741, 3 (2011)

    ADS  Article  Google Scholar 

  13. 13

    Rebull, L. M., Wolff, S. C. & Strom, S. E. Stellar rotation in young clusters: the first 4 million years. Astron. J. 127, 1029–1051 (2004)

    ADS  Article  Google Scholar 

  14. 14

    Movsessian, T. A., Magakian, T. Y. & Moiseev, A. V. Kinematics and the origin of the internal structures in HL Tauri jet (HH 151). Astron. Astrophys. 541, A16 (2012)

    ADS  Article  Google Scholar 

  15. 15

    Welch, W. J., Hartmann, L., Helfer, T. & Briceño, C. High-resolution, wide-field imaging of the HL Tauri environment in 13CO (1–0). Astrophys. J. 540, 362–371 (2000)

    ADS  CAS  Article  Google Scholar 

  16. 16

    Greaves, J. S., Richards, A. M. S., Rice, W. K. M. & Muxlow, T. W. B. Enhanced dust emission in the HL Tau disc: a low-mass companion in formation? Mon. Not. R. Astron. Soc. 391, L74–L78 (2008)

    ADS  Google Scholar 

  17. 17

    Hughes, A. M. et al. A spatially resolved inner hole in the disk around GM Aurigae. Astrophys. J. 698, 131–142 (2009)

    ADS  CAS  Article  Google Scholar 

  18. 18

    Hughes, A. M., Hull, C. L. H., Wilner, D. J. & Plambeck, R. L. Interferometric upper limits on millimeter polarization of the disks around DG Tau, GM Aur, and MWC 480. Astron. J. 145, 115 (2013)

    ADS  Article  Google Scholar 

  19. 19

    Rao, R., Girart, J. M., Lai, S.-P. & Marrone, D. P. Detection of a magnetized disk around a very young protostar. Astrophys. J. 780, L6 (2014)

    ADS  Article  Google Scholar 

  20. 20

    Loinard, L. et al. ALMA and VLA observations of the outflows in IRAS 16293–2422. Mon. Not. R. Astron. Soc. 430, L10–L14 (2013)

    ADS  CAS  Article  Google Scholar 

  21. 21

    Lay, O. P., Carlstrom, J. E. & Hills, R. E. Constraints on the HL Tauri protostellar disk from millimeter- and submillimeter-wave interferometry. Astrophys. J. 489, 917–927 (1997)

    ADS  Article  Google Scholar 

  22. 22

    Girart, J. M., Rao, R. & Marrone, D. P. Magnetic fields in the formation of sun-like stars. Science 313, 812–814 (2006)

    ADS  CAS  Article  Google Scholar 

  23. 23

    Stephens, I. W. et al. The magnetic field morphology of the class 0 protostar L1157-mm. Astrophys. J. 769, L15 (2013)

    ADS  Article  Google Scholar 

  24. 24

    Hull, C. L. H. et al. Misalignment of magnetic fields and outflows in protostellar cores. Astrophys. J. 768, 159 (2013)

    ADS  Article  Google Scholar 

  25. 25

    Hull, C. L. H. et al. TADPOL: A 1.3 mm survey of dust polarization in star-forming cores and regions. Astrophys. J. Suppl. Ser. 213, 13 (2014)

    ADS  Article  Google Scholar 

  26. 26

    Evans, N. J., II et al. The Spitzer c2d legacy results: star-formation rates and efficiencies; evolution and lifetimes. Astrophys. J. Suppl. Ser. 181, 321–350 (2009)

    ADS  Article  Google Scholar 

  27. 27

    Wardle, M. & Koenigl, A. The structure of protostellar accretion disks and the origin of bipolar flows. Astrophys. J. 410, 218–238 (1993)

    ADS  Article  Google Scholar 

  28. 28

    Sault, R. J., Teuben, P. J. & Wright, M. C. H. in Astronomical Data Analysis Software and Systems IV (eds Shaw, R. A., Payne, H. E. & Hayes, J. J. E. ) 433–436 (Astron. Soc. Pacif. Conf. Ser. Vol. 77, 1995)

    Google Scholar 

  29. 29

    Witzel, A., Heeschen, D. S., Schalinski, C. & Krichbaum, T. Kurzzeit-Variabilität extragalak-tischer Radioquellen. Mitt. Astron. Ges. Hamburg 65, 239 (1986)

    ADS  Google Scholar 

  30. 30

    Tafoya, D., Gómez, Y. & Rodríguez, L. F. Imaging MWC 349 from 7 millimeters to 90 centimeters. Astrophys. J. 610, 827–834 (2004)

    ADS  Article  Google Scholar 

  31. 31

    Marrone, D. P. & Rao, R. The submillimeter array polarimeter. Proc. SPIE 7020, 70202B (2008)

    ADS  Article  Google Scholar 

  32. 32

    Dullemond, C. P. & Dominik, C. Flaring vs. self-shadowed disks: the SEDs of Herbig Ae/Be stars. Astron. Astrophys. 417, 159–168 (2004)

    ADS  CAS  Article  Google Scholar 

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Acknowledgements

We thank R. L. Plambeck and C. L. H. Hull for consultation during the data reduction process and C. F. Gammie for discussions. This research made use of APLpy, an open-source plotting package for Python hosted at http://aplpy.github.com. Work at the Universities of Illinois and Maryland was supported by NSF AST-1139950 and AST-1139998, respectively. Support for CARMA construction was derived from the states of California, Illinois and Maryland, the James S. McDonnell Foundation, the Gordon and Betty Moore Foundation, the Kenneth T. and Eileen L. Norris Foundation, the University of Chicago, the Associates of the California Institute of Technology, and the National Science Foundation. Ongoing CARMA development and operations are supported under a cooperative agreement (NSF AST 08-38226) and by the CARMA partner universities.

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Data acquisition and reduction were performed by I.W.S., L.W.L. and M.F.-L. Polarization modelling was performed by W.K. and fitted by I.W.S. All authors analysed and discussed the observations and manuscript.

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Correspondence to Ian W. Stephens.

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The authors declare no competing financial interests.

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Stephens, I., Looney, L., Kwon, W. et al. Spatially resolved magnetic field structure in the disk of a T Tauri star. Nature 514, 597–599 (2014). https://doi.org/10.1038/nature13850

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