2020AJ....160...20S

The Vela and Puppis A supernova remnants (SNRs) comprise a large emission region of ∼8° diameter in the soft X-ray sky. The HaloSat CubeSat mission provides the first soft X-ray (0.4-7 keV) observation of the entire Vela SNR and Puppis A SNR region with a single pointing and moderate spectral resolution. HaloSat observations of the Vela SNR are best fit with a two-temperature thermal plasma model consisting of a cooler component with kT₁=0.19_–0.01^+0.01 keV in collisional ionization equilibrium and a hotter component with kT₂=1.06_–0.27^+0.45 keV in nonequilibrium ionization. Observations of the Puppis A SNR are best fit with a single-component plane-parallel shocked plasma model with kT=0.86_–0.05^+0.06 keV in nonequilibrium ionization. For the first time, we find the total X-ray luminosities of both components of the Vela SNR spectrum in the 0.5-7 keV energy band to be L_X=4.4_–1.4^+1.4×10³⁴ erg s^–1 for the cooler component and L_X=4.1_–1.5^+1.8×10³⁴ erg s^–1 for the hotter component. We find the total X-ray luminosities of the Vela and Puppis A SNRs to be L_X=8.4×10³⁴ erg s^–1 and L_X=6.7_–0.9^+1.1×10³⁶ erg s^–1.