Advertisement

Geomagnetism and Aeronomy

, Volume 58, Issue 8, pp 1144–1148 | Cite as

Slowly Varying Component of Radio Emission from TVLM 513-46546 and Continuous Sources of High Energy Electrons in the Coronae of UltraCool Stars

  • V. V. ZaitsevEmail author
  • A. V. StepanovEmail author
Article

Abstract

It is shown that a source generating a slowly varying or quiet component of radio emission from ultracool stars such as the brown dwarf TVLM 513-46546 can be the gyrosynchroton radiation from the magnetic loops system distributed quasi-uniformly over the star’s surface. Such a model explains the low modulation of the flux and makes it possible to understand the pumping mechanism of magnetic loops by high energy electrons. The main parameters of magnetic loops and which part of the star’s surface is the emission source are determined using the information on microwave radiation from the brown dwarf TVLM 513-46546.

Notes

ACKNOWLEDGMENTS

The work was supported by the Russian Academy of Sciences, program no. 28, “Space: Fundamental Processes and their Interconnections,” by the Russian Science Foundation, project no. 16-12-10448 (chapters 1, 2), no. 16-12-10528 (chapter 3), by the Russian Foundation for Basic Research, project no. 17-02-00091a (chapter 4), and by a state contract, project no. 0035-2014-0029.

REFERENCES

  1. 1.
    Berger, E., Gizis, J.E., Giampapa, M.S., Rutledge, R.E., Liebert, J., Martin, E., Basri, G., Fleming, T.A., Johns-Krull, C.M., Phan-Bao, N., and Sherry, W.H., Simultaneous multiwavelength observations of magnetic activity in ultracool dwarfs. I. The complex behavior of the M8.5 dwarf TVLM 513-46546, Astrophys. J., 2008, vol. 673, pp. 1080–1087.CrossRefGoogle Scholar
  2. 2.
    Dulk, G.A., Radio emission from the Sun and stars, Ann. Rev. Astron. Astrophys., 1985, vol. 23, pp. 169–224.Google Scholar
  3. 3.
    Guedel, M. and Benz, A.O., Similar X-ray/microwave ratios in solar flares and coronae of active stars, Astrophys. J., 1993, vol. 405, pp. L63–L66.CrossRefGoogle Scholar
  4. 4.
    Hallinan, G., Bourke, S., Lane, C., Antonova, A., Zavala, R.T., Brisken, W.F., Boyle, R.P., Vrba, F.J., Doyle, J.G., and Golden, A., Periodic bursts of coherent radio emission from an ultracool dwarf, Astrophys. J. Lett., 2007, vol. 663, pp. L25–L28.CrossRefGoogle Scholar
  5. 5.
    Osten, R.A., Hawley, S.L., Bastian, T.S., and Reid, I.N., The radio spectrum of TVLM 513-46546: Constraints on the coronal properties of a late M dwarf, Astrophys. J., 2006, vol. 637, pp. 518–521.CrossRefGoogle Scholar
  6. 6.
    Ravi, V., Hallinan, G., Hobbs, G., and Champion, D.J., The magnetosphere of the ultracool dwarf DENIS 1048–3956, Astrophys. J., 2011, vol. 735, pp. 1048–3956.CrossRefGoogle Scholar
  7. 7.
    Rutledge, R.E., Basri, G., Martín, E.L., and Bildsten, L., Chandra detection of an X-ray flare from the brown dwarf LP 944–20, Astrophys. J., 2000, vol. 538, pp. L141–L144.CrossRefGoogle Scholar
  8. 8.
    White, S.M., Kundu, M.R., and Jackson, P.D., Simple non-thermal models for the quiescent radio emission of dMe flare stars, Astron. Astrophys., 1989, vol. 225, pp. 112–124.Google Scholar
  9. 9.
    Yu, S., Hallinan, G., Doyle, J.G., MacKinnon, A.L., Antonova, A., Kuznetsov, A., Golden, A., and Zhang, Z.H., Modelling the radio pulses of an ultracool dwarf, Astron. Astrophys., 2011, vol. 525, pp. A39–A49.CrossRefGoogle Scholar
  10. 10.
    Zaitsev, V.V., Sustained oscillations of electric current in coronal magnetic loops and in arcades of magnetic loops, Solnechnaya i Solnenchno–Zemnaya Fizika-2017: Trudy GAO RAN (Solar and Solar–Terrestrial Physics: Proceedings of Main Astronomical Observatory RAS), St. Petersburg, 2017, pp. 153–156.Google Scholar
  11. 11.
    Zaitsev, V.V. and Stepanov, A.V., On the origin of intense radio emission from the brown dwarfs, Radiophys. Quantum Electron., 2017, vol. 59, no. 1, pp. 867–875.CrossRefGoogle Scholar

Copyright information

© Pleiades Publishing, Ltd. 2018

Authors and Affiliations

  1. 1.Institute of Applied Physics, Russian Academy of SciencesNizhniy NovgorodRussia
  2. 2.Central Astronomical Observatory, Russian Academy of SciencesPulkovo, St. PetersburgRussia

Personalised recommendations