Eruptive mass loss less than a year before the explosion of superluminous supernovae - I. The cases of SN 2020xga and SN 2022xgc

Open Access

Table 3.

Priors and posterior of the parameters fit with REDBACK for the generalized magnetar model.

Parameters	Priors	Best-fit values	Best-fit values
		SN 2020xga	SN 2022xgc

Initial magnetar spin-down luminosity L₀ (erg s⁻¹)	ℒ (10⁴⁰, 10⁵⁰)	$1 . 2_{- 0.1}^{+ 0.1} \times 10^{45}$ $1.2^{+0.1}_{-0.1} \times 10^{45}$	$8 . 1_{- 0.4}^{+ 0.6} \times 10^{44}$ $8.1^{+0.6}_{-0.4} \times 10^{44}$
Magnetar spin-down time t_SD (s)	ℒ (10², 10⁸)	$1 . 9_{- 0.5}^{+ 0.7} \times 10^{7}$ $1.9^{+0.7}_{-0.5} \times 10^{7}$	$1 . 9_{- 0.5}^{+ 0.9} \times 10^{7}$ $1.9^{+0.9}_{-0.5} \times 10^{7}$
Magnetar braking index n	𝒰 (1.5, 10)	$1 . 9_{- 0.3}^{+ 0.5}$ $1.9^{+0.5}_{-0.3}$	$5 . 5_{- 1.9}^{+ 2.5}$ $5.5^{+2.5}_{-1.9}$
Ejecta nickel mass fraction f_⁵⁶Ni	ℒ (10⁻⁶, 1)	$5 . 1_{- 4.9}^{+ 49.8} \times 10^{- 4}$ $5.1^{+49.8}_{-4.9} \times 10^{-4}$	$1 . 9_{- 1.9}^{+ 44.9} \times 10^{- 3}$ $1.9^{+44.9}_{-1.9} \times 10^{-3}$
Ejecta mass M_ej (M_⊙)	𝒰 (0.1, 100)	$7 . 0_{- 0.4}^{+ 0.4}$ $7.0^{+0.4}_{-0.4}$	$9 . 4_{- 0.7}^{+ 0.7}$ $9.4^{+0.7}_{-0.7}$
Supernova explosion energy E_SN (erg)	𝒰 (5 × 10⁴⁹, 3 × 10⁵¹)	$2 . 97_{- 0.04}^{+ 0.02} \times 10^{51}$ $2.97^{+0.02}_{-0.04} \times 10^{51}$	$2 . 4_{- 0.3}^{+ 0.3} \times 10^{51}$ $2.4^{+0.3}_{-0.3} \times 10 ^{51}$
Ejecta gamma-ray opacity κ_γ (cm² g⁻¹)	ℒ (10⁻⁴, 10⁴)	$8 . 3_{- 1.1}^{+ 1.2} \times 10^{- 3}$ $8.3^{+1.2}_{-1.1} \times 10^{-3}$	$3 . 6_{- 0.7}^{+ 0.9} \times 10^{- 3}$ $3.6^{+0.9}_{-0.7} \times 10^{-3}$
Photospheric plateau temperature T_floor (K)	𝒰 (3 × 10³, 2 × 10⁴)	$11494_{- 232}^{+ 242}$ $11494^{+242}_{-232}$	$6605_{- 205}^{+ 185}$ $6605^{+185}_{-205}$
Explosion date t_exp (MJD)	𝒰 (FD − 100, FD − 0.1)	$59096 . 3_{- 1.2}^{+ 1.2}$ $59096.3^{+1.2}_{-1.2}$	$59824 . 3_{- 0.6}^{+ 0.4}$ $59824.3^{+0.4}_{-0.6}$

Notes. The 𝒰 stands for uniform, and ℒ for log-uniform. The FD acronym stands for first detection and represents the date of the first real detection. The uncertainties are reported at 1σ significance.

Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.

Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.

Initial download of the metrics may take a while.