Table 4
Best-fit spectral parameters of SN 1987A for 2007 EPIC-pn, 2019 EPIC-pn, eROSITA Comm, eROSITA FL, eROSITA Comm+FL, and combined eROSITA +EPIC-pn 2019 observation with a three-component VPSHOCK model.
| Parameter | EPIC-pn | EPIC-pn | eROSITA | eROSITA | eROSITA Comm | eROSITA |
|---|---|---|---|---|---|---|
| 2007 | 2019 | Comm. | FL | + FL | + EPIC-pn 2019 | |
 |
0.244 ± 0.002 | 0.244 ± 0.002 | 0.26 ± 0.02 | 0.24 ± 0.01 | 0.25 ± 0.01 | 0.25 ± 0.01 |
| kT1 (keV) | 0.59 ± 0.01 | 0.66 ± 0.02 | 0.67 ± 0.03 | 0.69 ± 0.01 | 0.68 ± 0.01 | 0.68 ± 0.01 |
 |
 |
 |
 |
2.5 ± 0.5 | 1.79 ± 0.27 | 1.77 ± 0.26 |
| kT2 (keV) (frozen) | 1.15 | 1.15 | 1.15 | 1.15 | 1.15 | 1.15 |
| kT3 (keV) | 4.04 ± 0.26 | 3.68 ± 0.18 |  |
 |
 |
 |
 |
2.7 ± 0.1 | 42.9 ± 0.1 |  |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
| χ2 | 882.05 | 547.5 | 725 04 | 3004.7 | 2417.6 | 4189.4 |
| d.o.f. | 716 | 511 | 571 | 2463 | 1941 | 3185 |
Notes. Errors for Δχ2 = 2:71 confidence range. a: The normalisation is defined as 
where d is the distance to the SNR (in units of cm), ne and np are the number densities of electrons and protons, respectively. Expressed on a scale of 103. τu : opper limit on the ionisation time range in 1012 cm3 s. τ1 and τ3 are linked as 
(Zhekov et al. 2009; Dewey et al. 2012) and thus we do not report vpshock parameters for it.
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