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Discovery of X-rays from the protostellar outflow object HH2

Nature volume 413, pages 708–711 (2001)Cite this article

Abstract

Herbig–Haro (HH) objects have been known1,2 for 50 years to be luminous condensations of gas in star-forming regions, but their underlying physical nature is still being elucidated. Previously suggested models encompass newborn stars3, stellar winds clashing with nebular material4, dense pockets of interstellar gas excited by shocks from outflows5, and interstellar ‘bullets’ (ref. 6). Recent progress has been made with the jet-induced shock model7, in which material streams out of young stellar objects and collides with the surrounding interstellar medium. A clear prediction of this model is that the most energetic Herbig–Haro objects will emit X-rays, although they have not hitherto been detected8. Here we report the discovery of X-ray emission from one of the brightest and closest Herbig–Haro objects, HH2, at a level consistent with the model predictions. We conclude that this Herbig–Haro object contains shock-heated material located at or near its leading edge with a temperature of about 106 K.

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Figure 1: This figure shows the Orion Nebula region containing Herbig Haro 2.
Figure 2: Expanded views of the region observed with the Hubble Space Telescope centred on Herbig–Haro 2.
Figure 3: The HH2 X-rays are extended.

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Acknowledgements

We thank L. Townsley and P. Broos for their assistance. We also thank B. Reipurth and R. Blandford for helpful discussions. This research was performed in part by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration.

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Authors and Affiliations

  1. Jet Propulsion Laboratory, California Institute of Technology, Mail Stop 306-438, 4800 Oak Grove Drive, Pasadena, 91109, California, USA

    Steven H. Pravdo

  2. Department of Astronomy and Astrophysics, 525 Davey Laboratory, The Pennsylvania State University, University Park, 16802-6305, Pennsylvania, USA

    Eric D. Feigelson, Gordon Garmire, Yoshitomo Maeda & Yohko Tsuboi

  3. Astrophysics and Planetary Science, University of Colorado, Boulder, 80309, Colorado, USA

    John Bally

Authors
  1. Steven H. Pravdo
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  2. Eric D. Feigelson
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  3. Gordon Garmire
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  4. Yoshitomo Maeda
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  5. Yohko Tsuboi
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  6. John Bally
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Correspondence to Steven H. Pravdo.

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Pravdo, S., Feigelson, E., Garmire, G. et al. Discovery of X-rays from the protostellar outflow object HH2. Nature 413, 708–711 (2001). https://doi.org/10.1038/35099508

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