Hostname: page-component-cd9895bd7-hc48f Total loading time: 0 Render date: 2024-12-23T15:38:19.836Z Has data issue: false hasContentIssue false

Balmer-dominated shocks in Tycho’s SNR: omnipresence of CRs

Published online by Cambridge University Press:  17 October 2017

Sladjana Knežević
Affiliation:
Department of Particle Physics and Astrophysics, Faculty of Physics, The Weizmann Institute of Science, P.O.Box 26, Rehovot 76100, Israel email: [email protected]
Ronald Läsker
Affiliation:
Finnish Centre for Astronomy with ESO (FINCA), University of Turku, Väisäläntie 20, FI-21500 Kaarina, Finland
Glenn van de Ven
Affiliation:
Max Planck Institute for Astronomy, Königstuhl 17, D-69117, Heidelberg, Germany
Joan Font
Affiliation:
Instituto de Astrofísica de Canarias, Vía Láctea, La Laguna, Tenerife, Spain
John C. Raymond
Affiliation:
Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, U.S.A.
Coryn A. L. Bailer-Jones
Affiliation:
Max Planck Institute for Astronomy, Königstuhl 17, D-69117, Heidelberg, Germany
John Beckman
Affiliation:
Instituto de Astrofísica de Canarias, Vía Láctea, La Laguna, Tenerife, Spain
Giovanni Morlino
Affiliation:
INFN - Gran Sasso Science Institute, viale F. Crispi 7, 67100 L’Aquila, Italy
Parviz Ghavamian
Affiliation:
Department of Physics, Astronomy and Geosciences Towson University, Towson, MD 21252, U.S.A.
John P. Hughes
Affiliation:
Department of Physics and Astronomy, Rutgers University, 136 Frelinghuysen Road, Piscataway, NJ 08854, U.S.A.
Kevin Heng
Affiliation:
University of Bern, Center for Space and Habitability, Sidlerstrasse 5, CH-3012, Bern, Switzerland
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

We present wide-field, spatially and highly resolved spectroscopic observations of Balmer filaments in the northeastern rim of Tycho’s supernova remnant in order to investigate the signal of cosmic-ray (CR) acceleration. The spectra of Balmer-dominated shocks (BDSs) have characteristic narrow (FWHM ~ 10 km s−1) and broad (FWHM ~ 1000 km s−1) Hα components. CRs affect the Hα-line parameters: heating the cold neutrals in the interstellar medium results in broadening of the narrow Hα-line width beyond 20 km s−1, but also in reduction of the broad Hα-line width due to energy being removed from the protons in the post-shock region. For the first time we show that the width of the narrow Hα line, much larger than 20 km s−1, is not a resolution or geometric effect nor a spurious result of a neglected intermediate (FWHM ~ 100 km s−1) component resulting from hydrogen atoms undergoing charge exchange with warm protons in the broad-neutral precursor. Moreover, we show that a narrow line width ≫ 20 km s−1 extends across the entire NE rim, implying CR acceleration is ubiquitous, and making it possible to relate its strength to locally varying shock conditions. Finally, we find several locations along the rim, where spectra are significantly better explained (based on Bayesian evidence) by inclusion of the intermediate component, with a width of 180 km s−1 on average.

Type
Contributed Papers
Copyright
Copyright © International Astronomical Union 2017 

References

Bailer-Jones, C. A. L. 2012, A&A, 546, A89 Google Scholar
Blasco-Herrera, J., Fathi, K., Beckman, J., et al., 2010, 407, 2519Google Scholar
Cappellari, M. & Copin, Y. 2003, MNRAS, 342, 345 CrossRefGoogle Scholar
Chevalier, R. A., Kirshner, R. P., & Raymond, J. C. 1980, ApJ, 235, 186 Google Scholar
Foreman-Mackey, D., Hogg, D. W., Lang, D., & Goodman, J. 2013, PASP, 125, 306 Google Scholar
Ghavamian, P., Raymond, J. C., Hartigan, P., & Blair, W. P. 2000, ApJ, 535, 266 Google Scholar
Ghavamian, P., Raymond, J. C., Smith, R. C., & Hartigan, P. 2001, ApJ, 547, 995 Google Scholar
Goodman, J. & Weare, J. 2010, Comm. App. Math. Comp. Sci., 5, 65 CrossRefGoogle Scholar
Heng, K. 2010, PASA, 27, 23 Google Scholar
Hernandez, O., Fathi, K., Carignan, C., et al. 2008, PASP, 120, 665 Google Scholar
Lee, J-.J., Koo, B.-C., Raymond, J. C., et al. 2007, ApJ, 659, L133 CrossRefGoogle Scholar
Lee, J. J., Raymond, J. C., Park, S., & Blair, W. P. 2010, ApJ, 715, L146 CrossRefGoogle Scholar
Morlino, G., Bandiera, R., Blasi, P., & Amato, E. 2012, ApJ, 760, 137 Google Scholar
Morlino, G., Blasi, P., Bandiera, R., Amato, E., & Caprioli, D. 2013, ApJ, 100, 50 Google Scholar