The document discusses the fireshell model for classifying gamma-ray bursts (GRBs). It presents an analysis of two short GRBs, 08024B and 140402A, within the fireshell model. The fireshell model proposes two families of short GRBs originating from neutron star mergers. It estimates redshifts and isotropic energies for the two GRBs. The analysis finds that not all short GRBs produce GeV emission, and that GeV emission may be associated with accretion onto a black hole. It also notes that the absence of X-ray detections after some short GRBs is not surprising given observational limitations.

1. ECL17 - EXPLORING THE ENERGETIC UNIVERSE 2017
Università degli Studi di Roma "La Sapienza"
Piazzale Aldo Moro 5, Roma 00185 Italia
THE FIRESHELL MODEL NOMENCLATURE:
SUBCLASS OF SHORT GAMMA-RAY BURSTS
Yerlan Aimuratov
International Center for Relativistic Astrophysics Network
Piazza della Repubblica 10, Pescara 65122 Italia

2. output
• motivation and review
• phenomenology as way of research
• fireshell model and subclasses
• prototype of short GRB in fireshell model
• x-ray and GeV emission
• GRB 081024B and GRB 140402A
The fireshell model nomenclature: subclass of short gamma-ray bursts

3. bimodal distribution (Kouveliotou+ 1993)
Motivation and review 1/34

4. bimodal as hardness ratio vs T90
Motivation and review 2/34

5. Epeak-Eiso relation (Amati 2006) for long GRBs
Epeak-Eiso relation 3/34

6. Epeak-Eiso relation (Zhang+ 2012) for short GRBs
Epeak-Eiso relation 4/34

7. output
• motivation and review
• phenomenology as way of research
• fireshell model and subclasses
• prototype of short GRB in fireshell model
• x-ray and GeV emission
• GRB 081024B and GRB 140402A
The fireshell model nomenclature: subclass of short gamma-ray bursts

8. Epeak-Eiso relation (Zhang+ 2012) for short GRBs
Phenomenology as way of research 5/34

9. Epeak-Eiso relation (Zhang+ 2012) for short GRBs
Phenomenology as way of research 5/34

10. Epeak-Eiso relation (Zhang+ 2012) for short GRBs
Phenomenology as way of research 5/34

11. output
• motivation and review
• phenomenology as way of research
• fireshell model and subclasses
• prototype of short GRB in fireshell model
• x-ray and GeV emission
• GRB 081024B and GRB 140402A
The fireshell model nomenclature: subclass of short gamma-ray bursts

12. fireshell model scenario
Fireshell model and subclasses 6/34

13. fireshell model
Fireshell model and subclasses 7/34

14. nomenclature of fireshell model
The fireshell model nomenclature: GRB subclasses 8/34

15. evolutionary scheme by fireshell model
The fireshell model nomenclature: GRB evolutionary scheme 9/34

16. nomenclature of fireshell model
The fireshell model nomenclature: GRB subclasses 10/34

17. nomenclature of fireshell model
The fireshell model nomenclature: GRB subclasses 10/34

18. evolutionary scenario by fireshell model
- optically thick e+/- plasma with energy
E+/-
tot forms in the gravitational collapse
into BH [1]
- the fireshell engulfs the baryons
B=MBc2/E+/-
tot left over in the process of
collapse and thermalizes with baryons
- the surface of e+/- self-accelerates to
ultra-relativistic velocities up to the
transparency and the emission of
Proper-GRB
- after transparency shell slows down
by collisions with the CircumBurst
Medium (CBM) giving rise to Prompt
emission. CBM is modeled by filling
factor R=Aeff /Avis which takes into
account filamentary structures of the
medium [2-4][10] Damour & Ruffini 1975, Phys. Ref. Letters (35) 463
[11-13] Ruffini et al. 2001, ApJ (555) L 111, L 113, L 117
The fireshell model nomenclature: GRB evolutionary scenario 11/34

19. short gamma-ray bursts evolution tree
Recently we proposed [5] the
existence of two families of short
GRBs, both originating from NS
mergers:
- family-1 short bursts with Eiso<1052
erg and rest-frame spectral peak
energy Epeak<2 MeV, leading to a
massive Neutron Star (NS) as the
merged core
- family-2 short bursts with Eiso>1052
erg and Epeak>2 MeV, leading to a
Black Hole as merged core. High-
energy emission is explained by
existing of accretion disk near the BH
The fireshell model nomenclature: GRB evolutionary scenario 12/34
[19] Ruffini et al. 2015 ApJ 808, 190R

20. output
• motivation and review
• phenomenology as way of research
• fireshell model and subclasses
• prototype of short GRB in fireshell model
• x-ray and GeV emission
• GRB 081024B and GRB 140402A
The fireshell model nomenclature: subclass of short gamma-ray bursts

21. GRB 090227B as prototype
Prototype of short GRB in fireshell model 13/34

22. GRB 090227B as prototype
Prototype of short GRB in fireshell model 14/34

23. GRB 090227B on Epeak-Eiso relation diagram
Prototype of short GRB in fireshell model 15/34

24. GRB 090227B on Epeak-Eiso relation diagram
Prototype of short GRB in fireshell model 15/34

25. GRB 140619B analysis
Prototype of short GRB in fireshell model 16/34

26. GRB 140619B analysis
Prototype of short GRB in fireshell model 17/34

27. GRB 140619B as S-GRB and GeV emission
Prototype of short GRB in fireshell model 18/34

28. output
• motivation and review
• phenomenology as way of research
• fireshell model and subclasses
• prototype of short GRB in fireshell model
• X-ray and GeV emission
• GRB 081024B and GRB 140402A
The fireshell model nomenclature: subclass of short gamma-ray bursts

29. x-ray and GeV emission of short GRBs
X-ray and GeV emission 19/34

30. x-ray and GeV emission of short GRBs
X-ray and GeV emission 19/34

31. x-ray and GeV emission of short GRBs
X-ray and GeV emission 19/34

32. x-ray and GeV emission of short GRBs
X-ray and GeV emission 19/34

33. nomenclature of fireshell model
The fireshell model nomenclature: GRB subclasses 20/34

34. short gamma-ray bursts evolution tree
Recently we proposed [5] the
existence of two families of short
GRBs, both originating from NS
mergers:
- family-1 short bursts with Eiso<1052
erg and rest-frame spectral peak
energy Epeak<2 MeV, leading to a
massive Neutron Star (NS) as the
merged core
- family-2 short bursts with Eiso>1052
erg and Epeak>2 MeV, leading to a
Black Hole as merged core. High-
energy emission is explained by
existing of accretion disk near the BH
The fireshell model nomenclature: GRB evolutionary scenario 21/34
[19] Ruffini et al. 2015 ApJ 808, 190R

35. output
• motivation and review
• phenomenology as way of research
• fireshell model and subclasses
• prototype of short GRB in fireshell model
• X-ray and GeV emission
• GRB 081024B and GRB 140402A
The fireshell model nomenclature: subclass of short gamma-ray bursts

36. GRB 140402A: time-integrated analysis
The subclass of short gamma-ray bursts: 140402A 22/34

37. GRB 140402A: time-integrated analysis
The subclass of short gamma-ray bursts: 140402A 23/34

38. GRB 140402A: time-resolved analysis (P-GRB)
The subclass of short gamma-ray bursts: 140402A 23/34

39. GRB 140402A: time-resolved analysis (P-GRB)
The subclass of short gamma-ray bursts: 140402A 24/34

40. GRB 140402A: time-resolved analysis (Prompt)
The subclass of short gamma-ray bursts: 140402A 25/34

41. GRB 140402A: time-resolved analysis (Prompt)
The subclass of short gamma-ray bursts: 140402A 26/34

42. theoretical estimation of the redshift
Figure: parameters at transparency radius
for selected values of E+/-
tot
keV
E
kT peak
obs )0.1742.335(
92.3

The subclass of short gamma-ray bursts: 140402A 27/34
  52.511 
obs
theor
obstheor
kT
kT
zkTzkT
 
 





 1000
10
)1/(10000
)1/(1
90
902
1
4
EdEEN
EdEEN
F
z
t
dE
z
z
liso 
N(E) – photon spectrum
E – energy channel
[13] Ruffini et al. 2001 ApJ 555, L113 [19] Ruffini et al. 2015 ApJ 808, 190 [9] Muccino et al. 2013 ApJ 763, 125
)%1654(
)1/(4
)1/(4
2
2



 
 tot
BB
tottotl
GRBPBBl
tot
ee
GRBP
S
S
ztFd
ztFd
E
E


Output of the fitting provides us with following parameters:
- energy and time intervals
- energy fluxes
- Epeak

43. theoretical estimation of the redshift
The procedure:
- using the simulation and varying the values of E+/-
tot and B during the selection we found
the best fit to energy ratio of P-GRB and T90.
- peak energy Epeak is used for derivation of observed temperature kTobs
- simulation provided with fireshell temperature at transparency kTtheor by using which
redshift z was calculated
- by using redshift the isotropic energy was calculated
Redshift was estimated as z=5.52+/-0.93 and correspondingly Eiso = 4.7x1052 erg and B = 3.6x10-5
 BEtot
ee
,







 
theor
iso
GRBP
kT
E
E
, 





 z
kT
kT
obs
theor
1
 
 





 1000
10
)1/(10000
)1/(1
90
902
1
4
EdEEN
EdEEN
F
z
t
dE
z
z
liso 
The subclass of short gamma-ray bursts: 140402A 28/34
[13] Ruffini et al. 2001 ApJ 555, L113 [19] Ruffini et al. 2015 ApJ 808, 190 [9] Muccino et al. 2013 ApJ 763, 125

44. GRB 081024B
The subclass of short gamma-ray bursts: 081024B 29/34

45. GRB 081024B
The subclass of short gamma-ray bursts: 081024B 30/34

46. Consistency with observation
isoGRBP
iso
EE
z
B
ergE
)%2650()%2650(
)82.112.3(
10)8.26.4(
10)00.164.2(
5
52






[9] Muccino et al. 2013 ApJ 763, 125 [7] Zhang et al. 2012 ApJ 750, 88 [8] Calderone et al. 2015 MNRAS 448, 403
The subclass of short gamma-ray bursts: 081024B 31/34

47. GRB 140402A and subclass of S-GRBs
The fireshell model nomenclature: GRB subclasses 32/34
Figure: Epeak-Eiso relation and Family-2 short bursts [5]
[20] Ruffini et al. 2016 ApJ 832, 136 [7] Zhang et al. 2012 ApJ 750, 88 [8] Calderone et al. 2015 MNRAS 448, 403

48. GeV emission for subclass of S-GRBs
The fireshell model nomenclature: GRB subclasses 33/34
[21] Aimuratov et al. 2017 ApJ 844, 83 [22] Ruffini & Wheeler 1969

49. GeV emission for subclass of S-GRBs
The fireshell model nomenclature: GRB subclasses 33/34
[21] Aimuratov et al. 2017 ApJ 844, 83 [22] Ruffini & Wheeler 1969

50. x-ray afterglow upperlimits for short GRBs
The fireshell model nomenclature: GRB subclasses 34/34
[21] Aimuratov et al. 2017 ApJ 844, 83

51. conclusion
• We implemented a detailed analysis of the sources GRB 081024B and GRB
140402A within the fireshell model
• It was found that not all Short GRBs are able to produce GeV emission and its
production is supposed to be associated with accretion of the remnant mass onto
a Black Hole with an output being a relativistic jet
• The absence of an XRT detection after a short burst is not surprising.
Only in case of Swift-BAT triggering, quick response of Swift-XRT will provide us
with precise location and x-ray spectra and corresponding analysis could be done.
• Otherwise the method within the fireshell model can give a good redshift
estimation. we have derived for 081024B and 140402A respectively the redshift
z=3.12 and z=5.52, its isotropic energy Eiso=2.64x1052 and Eiso=4.7x1052 erg, and
baryon load B=4.6x10-5 andB=3.6x10-5.
• That makes possible to cross-check the ideas of phenomenological classification.
The fireshell model nomenclature: GRB evolutionary scheme

52. EXPLORING THE ENERGETIC UNIVERSE
Thank You for Attention!
The Fireshell Model Nomenclature:
Subclass of Short Gamma-Ray Bursts
Yerlan Aimuratov

53. evolutionary scheme by fireshell model
The fireshell model nomenclature: GRB evolutionary scheme 16/31

59. bimodal distribution (Kouveliotou+ 1993)
Bimodal distribution 2/31

60. Epeak-Eiso relation (Zhang+ 2012) for short GRBs
Epeak-Eiso relation 11/31

61. other phenomenological distributions
(Margutti+ 2013; Dainotti+ 2008; Bernardini+ 2012)
Other phenomenological distributions 12/31

62. other phenomenological distributions
(Margutti+ 2013; Dainotti+ 2008; Bernardini+ 2012)
Other phenomenological distributions 13/31

63. other phenomenological distributions
Other phenomenological distributions 14/31