gamma ray bursts: a new tool for astrophysics and cosmology? guido barbiellini university and infn...
Post on 21-Dec-2015
219 views
TRANSCRIPT
![Page 1: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/1.jpg)
Gamma Ray Bursts: a new tool for astrophysics and cosmology?
Guido BarbielliniUniversity and INFN Trieste
![Page 2: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/2.jpg)
Outline
Introduction GRB and cosmology
The Fireball model The Afterglow
External density Iron lines
The Prompt Emission Internal shocks problems
The Progenitor Supranova Collapsars Cannonballs
The fireworks model
BeppoSAX Afterglow detection HST host galaxies images
![Page 3: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/3.jpg)
Gamma-Ray Bursts
Temporal behaviourSpectral shape
Spatial distribution
![Page 4: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/4.jpg)
CGRO-BATSE (1991-2000)
CGRO/BATSE (25 KeV÷10 MeV)
![Page 5: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/5.jpg)
The great debate (1995) Fluence:10-7 erg cm-2 s-1
Distance: 1 GpcEnergy:1051 erg
Distance: 100 kpcEnergy: 1043 erg
Cosmological - Galactic?Need a new type of observation!
GRB: where are they?
![Page 6: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/6.jpg)
Costa et al. (1997)
BeppoSAX and the Afterglows
Kippen et al. (1998) Djorgoski et al. (2000)
• Good Angular resolution (< arcmin)• Observation of the X-Afterglow
• Optical Afterglow (HST, Keck)• Direct observation of the host galaxies• Distance determination
![Page 7: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/7.jpg)
GRB 021004: high precision radiography of ISM from z=2.3
Schaefer et al. 2002
![Page 8: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/8.jpg)
GRB host galaxies and Starburst galaxies
Berger et al 2002
![Page 9: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/9.jpg)
GRB and Cosmology
Schaefer 2003
![Page 10: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/10.jpg)
GRB and Cosmology
Djorgovski et al. 2003
![Page 11: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/11.jpg)
The compactness problem
Light curve variability ~ 1 ms
Non thermal spectra
• Fluence (): (0.1-10) x 10-6 erg/cm2 (/4) • Total Energy: E ~ 1051 ÷ 1052 erg
Briggs et al. (1999)
![Page 12: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/12.jpg)
Very High Optical Depth to pair production
Relativistic motion of the emitting region
The compactness problem
Size Pair fraction
Piran (1999)
![Page 13: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/13.jpg)
The Fireball model
• Relativistic motion of the emitting region• Shock mechanism converts the kinetic energy of the shells into radiation.• Baryon Loading problem
Internal Shocks Source activity Synchrotron Emission Rapid time Variability Low conversion efficiency
External Shock Synchrotron & SSC High conversion efficiency Not easy to justify the rapid variability
![Page 14: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/14.jpg)
The Afterglow model
External Shock scenario Forward + Reverse Shock Jet structure confirmation External density
Blast wave deceleration
![Page 15: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/15.jpg)
Afterglow Theory
Sari, Piran & Narayan (1998)
![Page 16: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/16.jpg)
Afterglow theory
Wijers, Rees & Meszaros (1997) Synchrotron Emission Power Law distribution of e-
Galama et al.(1998)
GRB 970508
GRB 970228
![Page 17: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/17.jpg)
Afterglow Observations
Akerlof et al. (1999)
Reverse shock flash
Covino et al. (1999)
Optical Polarization
GRB 990123
GRB 990510
![Page 18: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/18.jpg)
Afterglow Observations
Frail et al. (1997)
• Radio Scintillation
• Confirmation of Relativistic Motion
GRB 970508
![Page 19: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/19.jpg)
Afterglow Observations
Harrison et al (1999)
Achromatic Break
Woosley (2001)
![Page 20: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/20.jpg)
Jet and Energy Requirements
Frail et al. (2001)
![Page 21: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/21.jpg)
Jet and Energy Requirements
Berger et al. (2003)
![Page 22: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/22.jpg)
GRB 021004: surfing on density waves
Lazzati et al. 2002, Heyl and Perna 2002
![Page 23: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/23.jpg)
Iron Lines
Transient Absorbtion Line
Emission Lines
GRB 990705
Amati et al. (2000)
GRB 991216Piro et al. (2000)
![Page 24: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/24.jpg)
Iron Lines theory
Iron Line Geometry
Vietri et al. (2001)
![Page 25: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/25.jpg)
Internal Shock Scenario
Prompt emission Solve variability problem Spectral evolution
![Page 26: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/26.jpg)
Variability
External Shock variability
Internal Shock variability
![Page 27: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/27.jpg)
Norris et al. (1996)
Rise Time ~ Geometry of the Shell
Decay Time ~ Cooling Time
GRB Light curvePiran (1999)
![Page 28: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/28.jpg)
Spectral Evolution
![Page 29: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/29.jpg)
Spectral variability
alphabeta
Epeak
Preece et al. (2000)
![Page 30: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/30.jpg)
Progenitors
Two populations of GRB? Main models Possible solution?
![Page 31: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/31.jpg)
Progenitors
Short GRB
Long GRB
![Page 32: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/32.jpg)
NS/BH Binary Mergers
Merging of compact objects (NS-NS, NS-BH, BH-BH). These objects are observed in our Galaxy.The merging time is about 108 yr, via GW emission.
Eichler et. al. (1989)
![Page 33: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/33.jpg)
Collapsar model
• Very massive star that collapses in a rapidly spinning BH. • Identification with SN explosion.
Woosley (1993)
![Page 34: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/34.jpg)
Collapsar Model
Jets out of the Envelope
Paczynski (1998)
Ramirez Ruiz et al. (2002)
![Page 35: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/35.jpg)
Supranova
SupraMassive NSBaryon Clean Environment
Salgado et. al. (1994)
Vietri & Stella (1998)
![Page 36: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/36.jpg)
Cannonball
Two stage mechanism
Dar & De Rujula (2000)
![Page 37: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/37.jpg)
Towards a solution?
SN 1998bw - GRB 980425 (Galama et al. 98)
GRB 980326 (Bloom et al. 99)
SN evidence
![Page 38: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/38.jpg)
Towards a solution?Fruchter et al (1999)
Offset from Host Galaxy
Star forming region density
Galama & Wijers (2000)
![Page 39: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/39.jpg)
Towards a solution?
Distance from Host GalaxyFryer et al. (1999)
![Page 40: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/40.jpg)
GRB 011121: “evidence” for collapsar?
Bloom et al. (2002)
![Page 41: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/41.jpg)
GRB 011211: “evidence” for supranova?
Reeves et al. (2002)
![Page 42: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/42.jpg)
GRB 030329: the “smoking gun”?
(Zeh et al. 2003)
![Page 43: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/43.jpg)
GRB 030329: the “smoking gun”?
(Matheson et al. 2003)
![Page 44: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/44.jpg)
Vacuum Breakdown
Charged BHRuffini et al. (1999)
![Page 45: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/45.jpg)
Magnetic Fields and Vacuum Breakdown
Blandford-Znajek mechanismBlandford & Znajek (1977)Brown et al. (2000)Barbiellini, Celotti & Longo (2003)
![Page 46: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/46.jpg)
Guido Barbiellini Guido Barbiellini (University and INFN, Trieste)
Annalisa Celotti Annalisa Celotti (SISSA, Trieste)
Francesco LongoFrancesco Longo (University and INFN, Trieste)
The fireworks model for GRBThe fireworks model for GRB
![Page 47: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/47.jpg)
Available Energy
Blandford-Znajek mechanism for GRB
Blandford & Znajek (1977)Brown et al. (2000)Barbiellini & Longo (2001)
Figure from McDonald, Price and Thorne (1986)
M
ME bhBZ
54103.0
The energetics of the long duration GRB phenomenum is compared with models of a rotating Black Hole (BH) in a strong magnetic field generated by an accreting torus.
![Page 48: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/48.jpg)
Available Energy
Inelastic collision between a rotating BH (10 M)and a massive torus (0.1 M) that falls down onto the BH from the last stable orbit
Conservation of angular momentum:
Available rotational energy:
Available gravitational energy:
Total available energy:
III ttbhbh
3
3232 121
2
1
M
MM
I
IIE bh
bhbh
bhrot bhbh
2,
23
8
3332 cM
M
ME
M
MME t
bh
tbhrot
bh
tbhrot bh
2
3
1
3cM
R
MGM
R
MGME t
bh
bht
bh
bhtgrav
5310 gravrot EEE erg
A rough estimate of the energy extracted from a rotating BH is evaluated with a very simple assumption an inelastic collision between the rotating BH and the torus.
![Page 49: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/49.jpg)
Vacuum Breakdown
Polar cap BH vacuum breakdown
Figure from Heyl 2001
The GRB energy emission is attributed to an high magnetic field that breaks down the vacuum around the BH and gives origin to a e fireball.
Pair production rate
![Page 50: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/50.jpg)
Vacuum Breakdown
Critical magnetic field:
Charge acquired by a BH rotating in an external magnetic field (Wald 1974)
Electric field:
Pair volume:
13105.4 cB Gauss
161022 BJQ C
3
bhRVc
15102E V/cm
![Page 51: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/51.jpg)
The formation of the fireball
Pair density (e.g. Fermi 1966):
Magnetic field density:
Energy per particle:
Energy in plasmoid:
Number of plasmoids:
29108en cm-3
25108BU erg cm-3
40 10 acc erg
4510 Bcplasmoid UVE erg
810Bplasmoid
Bplasmoid E
EN
The energy released in the inelastic collision is available to create a series of plasmoids made of the pairs created and accelerated close to the BH.
![Page 52: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/52.jpg)
The formation of the fireball
Acceleration time scale in E field:
Particle collimation by B field:
Curvature radius:
Randomisation time scale by Compton Scattering in radiation field with temperature T0:
s1010 19
22
acceacc
acc eEc
cmt
s10sinsin
19
acccoll ct
cm)Gauss(
)GeV(103 6
B
E
s10 16accrandt
K101
8T 10
412
0
a
B
After the formation of the plasmoid the particles undergo three processes.
![Page 53: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/53.jpg)
Two phase expansion
Phase 1 (acceleration and collimation) ends when:
Assuming a dependence of the B field: this happens at
Parallel stream with
Internal “temperature”
collrand tt
3 RBcm108
1 R
acc301
1'
1
The first phase of the evolution occurs close to the engine and is responsible of energizing and collimating the shells. It ends when the external magnetic field cannot balance the radiation pressure.
![Page 54: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/54.jpg)
Two phase expansion
Phase 2 (adiabatic expansion) ends at the smaller of the 2 radii:
Fireball matter dominated:
Fireball optically thin to pairs:
R2 estimation Fireball adiabatic expansion
20 Mc
ERR
41
430
0 4
3
ppair TR
ERR
02 50RR
0
2'
'2
1R
R
The second phase of the evolution is a radiation dominated expansion.
![Page 55: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/55.jpg)
Jet Angle estimation
Figure from Landau-Lifšits (1976)
Lorentz factors
Opening angle
Result:
The fireball evolution is hypothized in analogy with the in-flight decay of an elementary particle.
![Page 56: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/56.jpg)
Energy Angle relationship
Predicted Energy-Angle relation
The observed angular distribution of the fireball Lorentz factor is expected to be anisotropic.
![Page 57: Gamma Ray Bursts: a new tool for astrophysics and cosmology? Guido Barbiellini University and INFN Trieste](https://reader035.vdocument.in/reader035/viewer/2022062714/56649d5a5503460f94a3a5cf/html5/thumbnails/57.jpg)
GRB 000131
ConclusionsAndersen et al. (2000)
GRB: Gravity at Action
GRB Cosmology