The X-ray continuum of Tycho's remnant mearured with GINGA
著者
和文:
Fink, H. H.,
Asaoka, I.,
Brinkmann, W.,
河合 誠之,
Koyama, K..
英文:
Fink, H. H.,
Asaoka, I.,
Brinkmann, W.,
Kawai, N.,
Koyama, K..
言語
English
掲載誌/書名
和文:
英文:
Astronomy and Astrophysics
巻, 号, ページ
Vol. 283
pp. 635-641
出版年月
1994年3月
出版者
和文:
英文:
会議名称
和文:
英文:
開催地
和文:
英文:
アブストラクト
The X-ray spectrum of Tycho's remant was observed in the energy range from 2 to 20 keV with Ginga in December, 1989. Fits of standard model spectra to the measured continuum above 4.5 keV showed that the spectrum of the remnant cannot satisfactorily be described by a single Bremsstrahlung component plus a Gaussian line for the Fe K-line blend. Such an approach was previously chosen to characterize Tycho's continuum measured with EXOSAT and Tenma up to 10 keV yielding divergent spectral parameters. Although the two-component modeling of the continuum yielded formally acceptable fits, the spectral parameters of the high energy component remained uncertain according to the very shallow chi2-valleys of the corresponding significance contours. The centroid of the Gaussian line is at 6.5 keV possibly indicating Fe line emssion from a hot plasma. A physical meaningful representation of Tycho's continuum is achieved by a multi-temperature spectrum provided by a numerical model. The 1-D model describes the hydrodynamical evolution of the remnant taking non-equilibrium ionization into account. The remarkable agreement between the model, and the measured continuum confirms the basic model assumption that a local temperature equilibrium between electrons and ions is almost instantaneously established in the remnant's X-ray emitting shell. From the model emissivity and the measured flux density a distance of Tycho of nearly 3 kpc is derived.