Hostname: page-component-84b7d79bbc-x5cpj Total loading time: 0 Render date: 2024-07-26T04:09:06.958Z Has data issue: false hasContentIssue false
  • English
  • Français

The origin of the Galactic center diffuse X-ray emission investigated by near-infrared imaging and polarimetric observations

Published online by Cambridge University Press:  22 May 2014

Shogo Nishiyama ,
Kazuki Yasui ,
Tetsuya Nagata ,
Tatsuhito Yoshikawa ,
Hideki Uchiyama  and
Motohide Tamura
Shogo Nishiyama
Affiliation:
National Astronomical Observatory of Japan, Mitaka, Tokyo 181-8588, Japan email: shogo.nishiyama@nao.ac.jp
Kazuki Yasui
Affiliation:
Department of Astronomy, Kyoto University, Kyoto 606-8502, Japan
Tetsuya Nagata
Affiliation:
Department of Astronomy, Kyoto University, Kyoto 606-8502, Japan
Tatsuhito Yoshikawa
Affiliation:
Department of Astronomy, Kyoto University, Kyoto 606-8502, Japan
Hideki Uchiyama
Affiliation:
Science Education, Faculty of Education, Shizuoka University, Shizuoka 422-8529, Japan
Motohide Tamura
Affiliation:
National Astronomical Observatory of Japan, Mitaka, Tokyo 181-8588, Japan email: shogo.nishiyama@nao.ac.jp
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.

The origin of the Galactic center diffuse X-ray emission (GCDX) is still under intense investigation. We have found a clear excess in a longitudinal GCDX profile over a stellar number density profile in the nuclear bulge region, suggesting a significant contribution of diffuse, interstellar hot plasma to the GCDX. We have estimated that contributions of an old stellar population to the GCDX are ∼50% and ∼20% in the nuclear stellar disk and nuclear star cluster, respectively. Our near-infrared polarimetric observations show that the GCDX region is permeated by a large scale, toroidal magnetic field. Together with observed magnetic field strengths in nearly energy equipartition, the interstellar hot plasma could be confined by the toroidal magnetic field.

Keywords

Galaxy: centermagnetic fieldspolarization
Type
Contributed Papers
Information
Proceedings of the International Astronomical Union , Volume 9 , Symposium S303: The Galactic Center: Feeding and Feedback in a Normal Galactic Nucleus , October 2013 , pp. 449 - 453
Copyright
Copyright © International Astronomical Union 2014 

References

Belmont, R., et al. 2005, ApJ 631, L53Google Scholar
Davies, B., et al. 2009, ApJ 694, 46Google Scholar
González-Fernández, C., et al. 2008, A&A 479, 131Google Scholar
Koyama, K., et al. 1989, PASJ 59, 245Google Scholar
Koyama, K., et al. 2007, Nature 339, 603Google Scholar
Makishima, K., 2006, ASCA Observations of Galaxies. In Makino, F. and Ohashi, T. (Eds.), New Horizon of X-Ray Astronomy. First Results from ASCA, pp. 171.Google Scholar
Muno, M. P., et al. 2004, ApJ 613, 326Google Scholar
Najarro, F., et al. 2009, ApJ 691, 1816Google Scholar
Nishiyama, S., et al. 2006, ApJ 638, 839Google Scholar
Nishiyama, S., et al. 2009, ApJ 690, 1648CrossRefGoogle Scholar
Nishiyama, S., et al. 2010, ApJ, 722, L23CrossRefGoogle Scholar
Nishiyama, S., et al. 2013, ApJ 769, L28Google Scholar
Revnivtsev, M., et al. 2009, Nature 458, 1142Google Scholar
Uchiyama, H., et al. 2011, PASJ 63, 903Google Scholar
Uchiyama, H., et al. 2013, PASJ 65, 19Google Scholar
Yamauchi, S., et al. 2009, PASJ 61, 225Google Scholar