Plasma temperature vs. distance inferred by assuming Sedov-Taylor expansion and adopting $kT=\frac{3}{16}\mu m_p{\upsilon }_{\text{sh}}^2$. The solid black line is the best-fit temperature obtained in Sect. 3.2. The dashed green, red, and blue lines give the temperature profiles for a SN energy of 10⁵⁰ erg, 10⁵¹ erg, and 10⁵² erg, respectively. The green, red, and yellow areas mark the allowed distances. See text for details.