Afterglow Plateau and Energy Injection from Magnetar: A Clue to Cosmological Standard Candles M. Xu and Y. F. Huang Department of Astronomy, Nanjing University, China 2011.03.07 The Prompt Activity of Gamma-Ray Bursts: their Progenitors, Engines, and Radiation Mechanisms Raleigh, NC

Outline Afterglow Plateau Energy Injection (EI) from Magnetar LT correlation LTE correlation Cosmological Standard Candles

Canonical X-ray afterglow light curve Zhang et al. 2006; Nousek et al. 2006

Energy Injection from Magnetar Fireball Energy Injection Kaspi et al. 2006

Afterglow and EI EI Xu et al. 2008, 2009

Phenomenological model Willingale et al. 2007

LX*∝Ta*-1.06 LT correlation Ta*=Ta/(1+z) Dainotti et al. 2010

EI from Magnetar ∝ -1 LX*∝Ta*-1.06 Assumptions： ∝ ~ ~ constant Same parameters for new born magnetars ---Cosmological standard candles ∝ -1

Energy Injection from Magnetar e+e- Fireball EI Dai 2004

Relativistic wind bubble Dai 2004

Einjection < EFireball Yu & Dai, 2007

LX*-T*-Eγ,iso correlation Dai 2004 EFireball ~ Einjection~ LW T LX* is related to fireball’s energy LX*-T*-Eγ,iso correlation

LTE correlation LX*∝Ta*-0.82Eγ,iso0.78 Xu & Huang 2011

LT vs LTE LTE correlation is much more tight than LT correlation. LT: Log[L/1047erg/s]=0.77[±0.14] -1.16 [±0.16] Log[T/103s] r=-0.73, P=5.6×10-8 σint=0.85±0.097 LTE correlation is much more tight than LT correlation. LTE: Log[L/1047erg/s]=0.73[±0.07] -0.82 [±0.08] Log[T/103s] +0.78[±0.06] Log[Eiso/1053erg] r=0.92, P=1.84×10-20 σint=0.38±0.05

Intermediate class GRBs LT correlation LTE correlation Long IC Dainotti et al. 2010 Xu & Huang 2011

Constrain the Cosmological parameters Xu & Huang 2011

Summary Afterglow plateau might be resulted from EI from Magnetar LTE-correlation is much more tight than LT- correlation Candidates of Cosmological Standard Candles Thank you!