ASCA observations of the northern outer lobe edge of the radio galaxy Centaurus A

Conference item

ASCA observation of the northern outer lobe edge region of the radio galaxy Centaurus A, similar to 3.5degrees north of its nucleus, is reported. Excess hard X-ray emission is seen around RA 13(hz)26m00(s), Dec. -39degrees20'00" (J2000 coordinates), together with soft diffuse X-ray emission extending all over the field of view of the GIS (similar to 50 arcmin in diameter). The spectrum of the soft diffuse emission is well described by an optically thin thermal plasma model with temperature kT similar to 0.6 keV modified by Galactic absorption. This emission is thought to arise from the thermal plasma associated with the outer lobe of Centaurus A and which has a thermal pressure of similar to 5 x 10(-13) dyn cm(-2). The excess hard emission is likely to be diffuse, and its spectrum is well described with a power law model of photon index similar to 1.7 or a thermal bremsstrahlung model of temperature kT greater than or similar to 11 keV. The nature of the hard emission is still unclear.

Authors: Isobe, N; Makishima, K; Tashiro, M; Kaneda, H

• Publication status: Published
• Journal: PARTICLES AND FIELDS IN RADIO GALAXIES
• Volume: 250
• Pages: 394-399
• Publication date: 2002-01-01
• Event title: Oxford Radio Galaxy Workshop
• ISBN: 1583810900