EXPANSION VELOCITY OF EJECTA IN TYCHO's SUPERNOVA REMNANT MEASURED BY DOPPLER BROADENED X-RAY LINE EMISSION

Journal Article · Fri Dec 10 00:00:00 EST 2010 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/725/1/894· OSTI ID:21474390

Hayato, Asami; Yamaguchi, Hiroya; Tamagawa, Toru; Makishima, Kazuo ^[1]; Katsuda, Satoru; Hwang, Una ^[2]; Hughes, John P ^[3]; Ozawa, Midori ^[4]; Bamba, Aya ^[5]; Kinugasa, Kenzo ^[6]; Terada, Yukikatsu ^[7]; Furuzawa, Akihiro; Kunieda, Hideyo ^[8]

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1. RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan)
2. NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)
3. Department of Physics and Astronomy, Rutgers University, 136 Frelinghuysen Road, Piscataway, NJ 08854-8019 (United States)
4. Department of Physics, Graduate School of Science, Kyoto University, Kita-Shirakawa, Sakyo-ku, Kyoto 606-8502 (Japan)
5. School of Cosmic Physics, Dublin Institute for Advanced Studies, 31 Fitzwilliam Place, Dublin 2 (Ireland)
6. Gunma Astronomical Observatory, 6860-86, Nakayama, Takayama-mura, Agatsuma-gun, Gunma 377-0702 (Japan)
7. Department of Physics, Saitama University, Shimo-Okubo 255, Sakura, Saitama 338-8570 (Japan)
8. Division of Particle and Astrophysical Science, Graduate School of Science, Nagoya University, Furo-cho, Nagoya 464-8602 (Japan)

We show that the expansion of ejecta in Tycho's supernova remnant (SNR) is consistent with a spherically symmetric shell, based on Suzaku measurements of the Doppler broadened X-ray emission lines. All of the strong K{alpha} line emissions show broader widths at the center than at the rim, while the centroid energies are constant across the remnant (except for Ca). This is the pattern expected for Doppler broadening due to expansion of the SNR ejecta in a spherical shell. To determine the expansion velocities of the ejecta, we applied a model for each emission-line feature having two Gaussian components separately representing red- and blueshifted gas, and inferred the Doppler velocity difference between these two components directly from the fitted centroid energy difference. Taking into account the effect of projecting a three-dimensional shell to the plane of the detector, we derived average spherical expansion velocities independently for the K{alpha} emission of Si, S, Ar, and Fe, and K{beta} of Si. We found that the expansion velocities of Si, S, and Ar ejecta of 4700 {+-} 100 km s{sup -1} are distinctly higher than that obtained from Fe K{alpha} emission, 4000 {+-} 300 km s{sup -1}, which is consistent with segregation of the Fe in the inner ejecta. Combining the observed ejecta velocities with the ejecta proper-motion measurements by Chandra, we derived a distance to Tycho's SNR of 4 {+-} 1 kpc.

• OSTI ID: 21474390
• Journal Information: Astrophysical Journal, Vol. 725, Issue 1; Other Information: DOI: 10.1088/0004-637X/725/1/894; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
DOPPLER BROADENING
EMISSION
PROPER MOTION
SUPERNOVA REMNANTS
SUPERNOVAE
SYMMETRY
THREE-DIMENSIONAL CALCULATIONS
X RADIATION
BINARY STARS
COSMIC RADIO SOURCES
ELECTROMAGNETIC RADIATION
ERUPTIVE VARIABLE STARS
IONIZING RADIATIONS
LINE BROADENING
MOTION
RADIATIONS
STARS
VARIABLE STARS