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Table 1

Physical properties of Cas A.

Parameter Symbol (units) Calculated/ Observed/ References
adopted estimated
value value

Progenitor mass (M) 19a 15–25 1, 2
Distance (kpc) 3.4a 3.4 3
Age (2004) (yr) 333a 333 4 based on 5
Explosion energy E (1051 erg) 2.2b 2.0 6
Ejecta mass Mej (M) 2.0b 2.2 7, 8
Forward shock radius Rb (pc) 2.50c* 2.32–2.72 9, 10, 11
Reverse shock radius Rr (pc) 1.71c* 1.52–2.01 9, 10, 11, 12
Forward shock velocity vb (km s-1) 5226c* 4000–6000 13
Reverse shock velocity vr (km s-1) 1586c* 1000–2000 6, 12
Circumstellar density (pre-shock) n0 (cm-3) 2.07b 1.99 8
Density contrast clumps/smooth ejecta χ 100a 100 14
Ejecta clumps density (pre-shock) ncloud (cm-3) 100a 100–300 14, 15
Smooth ejecta density (pre-shock) nsmooth (cm-3) 1.0c 0.1–10 12
Ejecta clumps diameter 2Rcloud (cm) 1.5 × 1016a (1−5) × 1016 16

Notes.

(a)

Adopted.

(b)

Allows a good match between measured and calculated values.

(c)

Calculated – this work.

(*)

Value in 2004.

Reference. [1] Young et al. (2006), [2] Vink et al. (1996), [3] Reed et al. (1995), [4] Hwang & Laming (2012), [5] Thorstensen et al. (2001), [6] Laming & Hwang (2003), [7] Willingale et al. (2002), [8] Willingale et al. (2003), [9] Hwang & Laming (2012), [10] Helder & Vink (2008), [11] Gotthelf et al. (2001), [12] Morse et al. (2004), [13] DeLaney & Rudnick (2003), [14] Sutherland & Dopita (1995), [15] Docenko & Sunyaev (2010), [16] Fesen et al. (2011).

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