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Complex structure of the supernova remnant HB 3HB 3 is an old, large (84 pc diameter) supernova remnant associated with the W3 H II region/molecular cloud complex. Observations of the imaging proportional counter (IPC) onboard the Einstein X-ray astronomy satellite have been reprocessed to yield a contour map of X-ray brightness and spectra of various regions of this remnant. The measured IPC flux is 2.4 x 10 to the -11th ergs per sq cm per s, giving a 0.2-4 keV luminosity of 1.6 x 10 to the 35th ergs/s for a column densityof 6 x 10 to the 21st per sq cm. The measured X-ray temperatures reveal a decrease from center to limb of the remnant of 1-0.3 keV. HB 3 is in the late adiabatic blast-wave phase of evolution, 30,000 to 50,000 yr old and with an initial blast energy of 3 x 10 to the 50th ergs. The X-ray map is compared with available radio and optical images. In X-rays, HB 3 has two components - a diffuse emission inside the 84 pc radio remnant and a ring of emission at the center of 30 pc in diameter. The diffuse emission is similar to that from other supernova remnants which are moderately obscured (column density, nH approximately 10 to the 22nd per sq cm). Three possibilities for the origin of the ring are explored: (1) a second supernova remnant, (2) a shocked shell in the interstellar medium surrounding HB 3, and (3) reverse-shock heated ejecta. There is no hot neutron star within the remnant.
Document ID
Document Type
Reprint (Version printed in journal)
External Source(s)
Leahy, D. A. (Calgary Univ. Alberta Canada)
Venkatesan, D. (Calgary, University Canada)
Long, K. S. (Johns Hopkins University Baltimore, MD, United States)
Naranan, S. (Tata Institute of Fundamental Research Bombay, India)
Date Acquired
August 12, 2013
Publication Date
July 1, 1985
Publication Information
Publication: Astrophysical Journal, Part 1
Volume: 294
ISSN: 0004-637X
Subject Category
Funding Number(s)
Distribution Limits