Journal of The Korean Astronomical Society (천문학회지)

The Korean Astronomical Society (한국천문학회)
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IMAGING NON-THERMAL X-RAY EMISSION FROM GALAXY CLUSTERS: RESULTS AND IMPLICATIONS

  • HENRIKSEN MARK (Joint Center for Astrophysics, Physics Department, University of Maryland) ;
  • HUDSON DANNY (Joint Center for Astrophysics, Physics Department, University of Maryland)
  • Published : 2004.12.01
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Abstract

We find evidence of a hard X-ray excess above the thermal emission in two cool clusters (Abell 1750 and IC 1262) and a soft excess in two hot clusters (Abell 754 and Abell 2163). Our modeling shows that the excess components in Abell 1750, IC 1262, and Abell 2163 are best fit by a steep power law indicative of a significant non-thermal component. In the case of Abell 754, the excess emission is thermal, 1 ke V emission. We analyze the dynamical state of each cluster and find evidence of an ongoing or recent merger in all four clusters. In the case of Abell 2163, the detected, steep spectrum, non-thermal X-ray emission is shown to be associated with the weak merger shock seen in the temperature map. However, this shock is not able to produce the flatter spectrum radio halo which we attribute to post-shock turbulence. In Abell 1750 and IC 1262, the shocked gas appears to be spatially correlated with non-thermal emission suggesting cosmic-ray acceleration at the shock front.

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References

  1. Bell, A. R., 1978, MNRAS, 182, 147 https://doi.org/10.1093/mnras/182.2.147
  2. Colless, M., et al. 2001, MNRAS, 321, 277 https://doi.org/10.1046/j.1365-8711.2001.04044.x
  3. Dolag, K., Bartelmann, M., & Lesch, H. 2002, A&A, 387, 383 https://doi.org/10.1051/0004-6361:20020241
  4. Fusco-Femiano, R. et al. 1999, ApJ, 513, 21 https://doi.org/10.1086/311902
  5. Fukazawa, et al. 2001, ApJ, 546, 87 https://doi.org/10.1086/318863
  6. Gruber, D., & Rephaeli, Y. 2002, ApJ, 565, 877 https://doi.org/10.1086/324699
  7. Henriksen, M. 1998, PASJ, 50, 389 https://doi.org/10.1093/pasj/50.4.389
  8. Henriksen, M. 1999, ApJ, 511, 666 https://doi.org/10.1086/306729
  9. Henriksen, M., Hudson, D., & Tittley, E. 2004, ApJ, 610, 762 https://doi.org/10.1086/420810
  10. Henriksen, M., & Mushotzky, R. 2001, ApJ, 553, 84 https://doi.org/10.1086/320646
  11. Hudson, D., & Henriksen, M. 2003, ApJL, 595, 1 https://doi.org/10.1086/377337
  12. Kaastra, J. 1999, ApJ, 519, 119 https://doi.org/10.1086/312112
  13. Machacek, M., Bautz, M., Canizares, C., & Garmire, G. 2002, ApJ, 567, 188 https://doi.org/10.1086/338551
  14. Miniati, F., Jones, T. W., Kang, H., & Ryu, D. 2001, ApJ562, 233 https://doi.org/10.1086/323434
  15. Novicki, M. C., Sornig, M., & Henry, J. P. 2002, AJ, 124, 2413 https://doi.org/10.1086/344162
  16. Oegerle W., & Hill, j. 2001, AJ, 251, 122, 2858
  17. Rephaeli, Y. & Gruber, D. 2004, ApJ, 606, 825 https://doi.org/10.1086/383123
  18. Ryu, D., Kang, H., Hallman, E., & Jones, T. 2003, ApJ, 593, 599 https://doi.org/10.1086/376723
  19. Silverman, J., Harris, D., & Junor, W. 1998, AA, 335, 44
  20. Tittley, E., & Henriksen, M. 2004, ApJ (in press)

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