Central engine models Y NSNS merger model (Paczynski1986; Eichleret al 1989) Y Collapsar models Woosley 1993; Paczynski1998 MacFadyen Woosley 1999) Y Magnetar model(Usov 1992; Duncan& Thompson 1992) Y NSSS phase transition models( Cheng Dai 1996; Dai& Lu 1998a; Paczynski& Haensel 2005) Y Supranova models(Vietri& Stella 1998)
Central engine models ✓ NS-NS merger model (Paczynski 1986; Eichler et al. 1989) ✓ Collapsar models (Woosley 1993; Paczynski 1998; MacFadyen & Woosley 1999) ✓ Magnetar model (Usov 1992; Duncan & Thompson 1992) ✓ NS-SS phase transition models (Cheng & Dai 1996; Dai & Lu 1998a; Paczynski & Haensel 2005) ✓ Supranova models (Vietri & Stella 1998)
X-rays. visible then radio Stellar-mass black hole cretion disk (100km) Helium Collapsar IS-NS merger model Collapsar model
NS-NS merger model Collapsar model
Summary: fireball shock model Ultra Inner relativistic engine jet Internal shocks External shocks
Summary: fireball + shock model
Basic assumptions in the standard afterglow model O A spherical, ultrarelativistic fireball is ejected 2 The total energy of the shocks is released impulsively before their formation 3 The unshocked medium is homogeneous, and its density is of the order of 1 cm-3 a The electron and magnetic energy-density fractions of the shocked medium and the index p of the electron power-law distribution are constant 6 The emission mechanism is synchrotron radiation
Basic assumptions in the standard afterglow model ① A spherical, ultrarelativistic fireball is ejected; ② The total energy of the shocks is released impulsively before their formation; ③ The unshocked medium is homogeneous, and its density is of the order of 1 cm-3 ; ④ The electron and magnetic energy-density fractions of the shocked medium and the index p of the electron power-law distribution are constant; ⑤ The emission mechanism is synchrotron radiation
Physical effects in afterglows o Jets(Rhoads 1997, 1999 Sari, Piran halpern 1999 Dai cheng 2001 Postburst energy injection(Dai Lu 1998a, 2000 2001: Rees meszaros 1998: Panaitescu meszaros 1998; Kumar piran 2000a, b; Zhang meszaros 200la, b; Nakar piran 2003; Dai 2004) 3 Environments including stellar winds and dense media(Dai& Lu 1998b, 1999, 2002; Meszaros, Rees wijers 1998: Chevalier &li 1999. 2000: dai Wu 2003: Chevalier et al. 2004) Model parameters changed(Yost et al. 2003) 5 Other emission mechanisms including IC scattering (Wei lu 1998; Sari esin 2001 Panaitescu Kumar 2001; Zhang meszaros 2002)
① Jets (Rhoads 1997, 1999; Sari, Piran & Halpern 1999; Dai & Cheng 2001) ② Postburst energy injection (Dai & Lu 1998a, 2000, 2001; Rees & Meszaros 1998; Panaitescu & Meszaros 1998; Kumar & Piran 2000a,b; Zhang & Meszaros 2001a,b; Nakar & Piran 2003; Dai 2004) ③ Environments including stellar winds and dense media (Dai & Lu 1998b, 1999, 2002; Meszaros, Rees & Wijers 1998; Chevalier & Li 1999, 2000; Dai & Wu 2003; Chevalier et al. 2004) ④ Model parameters changed (Yost et al. 2003) ⑤ Other emission mechanisms including IC scattering (Wei & Lu 1998; Sari & Esin 2001; Panaitescu & Kumar 2001; Zhang & Meszaros 2002) Physical effects in afterglows