The thermal emission for knot A of radio galaxy M87 by Chandra

The jet may compress an interstellar medium and soft X ray outside the jet may be absorbed by a compressed interstellar medium and thermal emission heated by a shock is expected inside the jet. Thermal emission was found for HST-1 and knot A of M87 in X ray energy spectra analysis by Chandra (Osone, 2017). The X ray image of the surrounding of the jet of M87 was studied by Chandra (Osone 2024). I find a soft X ray dip in a south region outside knot A. Therefore, by taking only a north region outside knot A as a background, where there is no soft X ray dip, I analyze X ray energy spectra for knot A by Chandra and confirm thermal emission with a high significance.