Tight LisoEp 0 Relation of Long GammaRay Bursts
Tight Liso-Ep-Γ 0 Relation of Long Gamma-Ray Bursts Enwei Liang Guangxi University, China IAUS 324: New Frontiers in BH Astrophys. 2016. 9. 12 -9. 16, Ljubljana Selovenia
General Picture of Gamma-Ray Bursts GRBs and their afterglows are produced from extremely relativistic jets powered by the central engine. V ≥ 0. 9999 c 2
Estimating the Initial Γ 0 of GRB jets n. With the fireball deceleration time(e. g. , Sari & Piran 1999) Liang + 2010 n. With the "compactness" argument: (e. g. , Lithwick & Sari 2001) n. With the photosphere radiation: (e. g. Zou + 2015) Tang + 2014 Peng + 2014
Optical and X-ray afterglow Cartoon Lightcurves X-ray Emission components Optical Emission components Zhang et al. 2006, Ap. J; Li, Liang et al. 2012, Ap. J
Relation between afterglow onset and prompt gamma-rays l Optical afterglow onset is detected for 1/3 of GRBs l Onset peak luminosity is correlated with prompt gamma-ray luminosity. Liang et al. 2010, Ap. J
Eiso (or Liso)-Γ 0 Relation A tight correlation between the Eiso and the Lorentz factor of GRB fireball Liang et al. 2010,2013, Ap. J; LV et al. 2012, Ap. JL
Eiso (or Liso)-Ep Relation These relations was found with GRBs detected with Beppo. SAX and also confirmed with Swift/BAT and Fermi/GBM GRBs. Amati et al. 2012, IJMPD Yonetoku et al. 2004, Ap. J Lu et al. 2012, Ap. J
Eiso (or Liso)-Ep vs. Eiso (or Liso)-Γ 0 Relation Amati et al. 2012, IJMPD n n Liang et al. 2010, Ap. J Is the large intrinsic dispersion of pair correlations due to missing of the third part? Relation among the three parameters?
A tight Liso-Ep, z-Γ 0 relation GRB 060218: Γ 0 ~ 2. 3 (Soderberg + 2006) Liang + 2015, Ap. J 9
A tight Liso-Ep, z-Γ 0 relation Double check with GRBs whose Γ 0 are derived from the spectral cutoff energy observed with Fermi/LAT. GRB 060218: Γ 0 ~ 2. 3 (Soderberg + 2006) Liang + 2015, Ap. J 10
Liso-Ep, z-Γ 0 as a new GRB cosmology ruler? n n Ejet-Ep relation (Ghirlanda + 2004) Eiso-Ep-tjet relation (Liang & Zhang 2005) Dai, Liang, & Xu 2004, Ap. JL; Liang & Zhang 2005, Ap. J 11
Liso-Ep, z-Γ 0 as a new GRB cosmology ruler? n n n Advantages: q A tighter relation than previous ones. Issues: q Needing to be confirmed with LL-GRBs (moderate relativistic jets? ) q Needing to geometric correction to Liso q Identifying the cosmic evolution of jet luminosity. Liang + 2015; Xin + 2016 ? 12
3. Our On-Going Observational Projec GRB trigger Follow-up Flux Hu+ 2014 GRBs Optical Tels Singer+2012 magnitude R=13 Mini-GWAC R=16 GWAC R=19 60/80 cm -400 s -200 s 0 100 s 5 m 1 h 1 d R=21 i. PTF
Our Current Optical Monitoring Project 10 m trigger 30 s Identification and early photometry hours Spectrum、 redshift Late photometry GWAC/GRB alert 60/80 cm Telescope 2 m telescope
Examples of Our Monitoring Results Mini-GWAC upper limit : M=13. 2 GRB 160131 A B, V, R, I observations with our 60/ 80 cm telescopes in Xinglong Observatory. Liang + 2016, in prep.
GRB 140629 Xin + 2016, Ap. J, submitted
Zhong + 2016, Ap. J, in press
Huang + 2016, Ap. J, in press
Xin + 2016 a, Ap. J
Summary Thanks! l Measuring the jet initial Lorentz factors of GRBs with the fireball deceleration time observed in the optical band range from ~100 to 1000. l The Lorentz factors are correlated with Liso (or Eiso), and a tighter correlation is found by adding Ep. l The Liso-Ep, z-Γ 0 may be a promising GRB cosmology ruler, but issues are still there. l Our new observational project is going on for pushing the cosmology use of this relation. 21
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