pascos 031 gamma ray bursts – the brightest explosions in the universe tsvi piran hebrew...

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PASCOS 03 1 Gamma Ray Bursts – The Gamma Ray Bursts – The Brightest Explosions in the Brightest Explosions in the Universe Universe Tsvi Piran Hebrew University, Tsvi Piran Hebrew University, Jerusalem Jerusalem W. Benz W. Benz M. Davies M. Davies David Eichelr David Eichelr Philip Hughes Philip Hughes Jonahtan Katz Jonahtan Katz Shiho Kobayashi Shiho Kobayashi C. Kochaneck C. Kochaneck P. Kumar P. Kumar Mario Livio Mario Livio Mark Miller Mark Miller R. Narayan R. Narayan B. Paczynski B. Paczynski S. Rosswog S. Rosswog Re’em Sari Re’em Sari David Schramm David Schramm Jacob Shaham Jacob Shaham Wai Mo Suen Wai Mo Suen F. Thielmann F. Thielmann E. Waxman E. Waxman Shai Ayal Shai Ayal Ehud Cohen Ehud Cohen Jonathan Granot Jonathan Granot Ehud Naker Ehud Naker Amotz Shemi Amotz Shemi

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Page 1: PASCOS 031 Gamma Ray Bursts – The Brightest Explosions in the Universe Tsvi Piran Hebrew University, Jerusalem  W. Benz  M. Davies  David Eichelr

PASCOS 03 1

Gamma Ray Bursts – The Brightest Gamma Ray Bursts – The Brightest Explosions in the UniverseExplosions in the UniverseTsvi Piran Hebrew University, Tsvi Piran Hebrew University, JerusalemJerusalem

W. BenzW. Benz M. DaviesM. Davies David EichelrDavid Eichelr

Philip HughesPhilip Hughes Jonahtan Katz Jonahtan Katz Shiho KobayashiShiho Kobayashi C. KochaneckC. Kochaneck P. Kumar P. Kumar Mario Livio Mario Livio

Mark MillerMark Miller R. NarayanR. Narayan

B. Paczynski B. Paczynski S. Rosswog S. Rosswog Re’em SariRe’em Sari David Schramm David Schramm Jacob Shaham Jacob Shaham Wai Mo Suen Wai Mo Suen

F. ThielmannF. Thielmann E. WaxmanE. Waxman Shai Ayal Shai Ayal Ehud CohenEhud Cohen Jonathan Granot Jonathan Granot Ehud NakerEhud Naker Amotz ShemiAmotz Shemi

Page 2: PASCOS 031 Gamma Ray Bursts – The Brightest Explosions in the Universe Tsvi Piran Hebrew University, Jerusalem  W. Benz  M. Davies  David Eichelr

PASCOS 03 2

THE DISCOVERYTHE DISCOVERY Gamma-Ray Bursts (GRBs) Short (few seconds) bursts of Gamma-Ray Bursts (GRBs) Short (few seconds) bursts of

100keV- few MeV100keV- few MeV were discovered accidentally by were discovered accidentally by

Klebesadal Strong and Olson in 1967 Klebesadal Strong and Olson in 1967

using the Vela satellites using the Vela satellites

(defense satellites sent to monitor (defense satellites sent to monitor

the outer space treaty). the outer space treaty). The discovery was reported for the The discovery was reported for the

first time only in 1973.first time only in 1973.

• There was an “invite prediction”. There was an “invite prediction”. S. Colgate was asked to predict S. Colgate was asked to predict GRBs as a scientific excuse for the GRBs as a scientific excuse for the launch of the Vela Satellites launch of the Vela Satellites

Page 3: PASCOS 031 Gamma Ray Bursts – The Brightest Explosions in the Universe Tsvi Piran Hebrew University, Jerusalem  W. Benz  M. Davies  David Eichelr

PASCOS 03 3

Duration 0.01-100sDuration 0.01-100s Two populations (long and short)Two populations (long and short)

~ 1 BATSE burst per day~ 1 BATSE burst per day - (a local rate of ~2 Gpc- (a local rate of ~2 Gpc-3-3 yr yr-1 -1 )) ~100keV photons~100keV photons Non thermal SpectrumNon thermal Spectrum

(very high energy tail, (very high energy tail, up to GeV, 500GeV?)up to GeV, 500GeV?) Rapid variability (less than 10ms)Rapid variability (less than 10ms) Cosmological Origin Cosmological Origin The luminosity of a GRB is comparable to the luminosity of The luminosity of a GRB is comparable to the luminosity of

the rest of the Universe combined.the rest of the Universe combined.

GRBsGRBs

Compton-GROCompton-GRO

Page 4: PASCOS 031 Gamma Ray Bursts – The Brightest Explosions in the Universe Tsvi Piran Hebrew University, Jerusalem  W. Benz  M. Davies  David Eichelr

PASCOS 03 4

GRB 971214GRB 971214

Page 5: PASCOS 031 Gamma Ray Bursts – The Brightest Explosions in the Universe Tsvi Piran Hebrew University, Jerusalem  W. Benz  M. Davies  David Eichelr

PASCOS 03 5

Why are GRBs so Exciting?Why are GRBs so Exciting?

GRBs involve the fastest GRBs involve the fastest macroscopic relativistic macroscopic relativistic motion observed so far motion observed so far

((>100)>100)

GRBs signal (most GRBs signal (most likely) the fromation likely) the fromation

of newborn black of newborn black holes.holes.

Sources of GRBs Sources of GRBs (merging NS or (merging NS or

Collapsars) are also Collapsars) are also sources of Gravitational sources of Gravitational

radiationradiation

GRBs are the best GRBs are the best cosmological cosmological

indicators known indicators known today for the early today for the early (z~5-10) universe.(z~5-10) universe.

GRBs are the brightest and most luminous objects known today.GRBs are the brightest and most luminous objects known today.

GRBs are the most relativistic objects known today.GRBs are the most relativistic objects known today.

Page 6: PASCOS 031 Gamma Ray Bursts – The Brightest Explosions in the Universe Tsvi Piran Hebrew University, Jerusalem  W. Benz  M. Davies  David Eichelr

PASCOS 03 6

1974: The NY Texas Symposium1974: The NY Texas Symposium Meegan - GRB distribution is isotropic.Meegan - GRB distribution is isotropic. Ruderman - First theoretical review:Ruderman - First theoretical review:

Cosmological origin ?Cosmological origin ? Relativistic Motion ?Relativistic Motion ? Galactic origin!?Galactic origin!? > 30 models (> 30 models (More models than burstsMore models than bursts) - None ) - None

even remotely relevant.even remotely relevant. During the late seventies a consensus formed that During the late seventies a consensus formed that

GRBs originate on galactic neutron stars.GRBs originate on galactic neutron stars.

Page 7: PASCOS 031 Gamma Ray Bursts – The Brightest Explosions in the Universe Tsvi Piran Hebrew University, Jerusalem  W. Benz  M. Davies  David Eichelr

PASCOS 03 7

BATSE on Compton -BATSE on Compton -

GRO GRO (Fishman et. al.)(Fishman et. al.)

discovered that the discovered that the

distribution of GRBs distribution of GRBs

is isotropic:is isotropic:

GRBs areGRBs are Cosmological Cosmological By now there are redshift measurements for the afterglow By now there are redshift measurements for the afterglow of a dozen bursts. of a dozen bursts.

1991: BATSE – 1991: BATSE – The First RevolutionThe First Revolution

Page 8: PASCOS 031 Gamma Ray Bursts – The Brightest Explosions in the Universe Tsvi Piran Hebrew University, Jerusalem  W. Benz  M. Davies  David Eichelr

PASCOS 03Tsvi Piran HU 8

35

40

45

50

55

60

1970

1972

1974

1976

1978

1980

1982

1984

1986

1988

1990

1992

1994

1996

1998

2000

2002

Lo

g

( E )

Revised Energy EstimatesRevised Energy EstimatesThe observed fluences are ~10The observed fluences are ~10-7 -7 - 10- 10-5 -5 ergs/cmergs/cm22

24

)1(

Ld

zEF

Cosmological Cosmological corrections.corrections.

10105252ergsergs

(E)

z~1 z~1 E~10 E~105252ergs ergs GRBs are the GRBs are the (electromagnetically) (electromagnetically) most luminous objects most luminous objects in the Universe. in the Universe. For a few second the For a few second the luminosity of a GRB is luminosity of a GRB is comparable to the comparable to the luminosity of the rest of luminosity of the rest of the Universe.the Universe.

Page 9: PASCOS 031 Gamma Ray Bursts – The Brightest Explosions in the Universe Tsvi Piran Hebrew University, Jerusalem  W. Benz  M. Davies  David Eichelr

PASCOS 03 9

Implications of 10Implications of 105252ergsergs

Need ultrarelativistic motion to get Need ultrarelativistic motion to get 10105252erg out from a compact source within erg out from a compact source within such a short time scale.such a short time scale.

New Physics?New Physics?

TP Caltech 2001 12

The Fireball ModelThe Fireball Model

compact sourcecompact source

Relativistic Relativistic ParticlesParticles>100>100oror PoyntingPoynting fluxflux

ShocksShocks

rays

~ 10~ 107 7 cmcm

Goodman; Goodman; PaczynskiPaczynski; ; Shemi Shemi & Piran, & Piran, NarayanNarayan, , PaczynskiPaczynski & Piran; & Piran; MeszarosMeszaros & Rees,& Rees,

The The FIREBALFIREBAL

MODELMODEL

Page 10: PASCOS 031 Gamma Ray Bursts – The Brightest Explosions in the Universe Tsvi Piran Hebrew University, Jerusalem  W. Benz  M. Davies  David Eichelr

PASCOS 03 10

The Fireball ModelThe Fireball Model

compact sourcecompact source

Relativistic Relativistic ParticlesParticles>100>100or Poynting fluxor Poynting flux

~ 10~ 107 7 cmcm

ShocksShocks

rays

Goodman; Paczynski; Shemi & Piran, Goodman; Paczynski; Shemi & Piran, Narayan, Paczynski & Piran; Meszaros & Rees,Narayan, Paczynski & Piran; Meszaros & Rees,

Page 11: PASCOS 031 Gamma Ray Bursts – The Brightest Explosions in the Universe Tsvi Piran Hebrew University, Jerusalem  W. Benz  M. Davies  David Eichelr

PASCOS 03 11

Supernova Remnants (SNRs) - Supernova Remnants (SNRs) - the Newtonian Analoguethe Newtonian Analogue

~ 10 solar masses are ~ 10 solar masses are ejected at ~10,000 ejected at ~10,000 km/sec during a km/sec during a supernova explosion. supernova explosion.

The ejecta is slowed The ejecta is slowed down by the interstellar down by the interstellar medium (ISM) emitting medium (ISM) emitting x-ray and radio for x-ray and radio for ~10,000 years.~10,000 years.

Page 12: PASCOS 031 Gamma Ray Bursts – The Brightest Explosions in the Universe Tsvi Piran Hebrew University, Jerusalem  W. Benz  M. Davies  David Eichelr

PASCOS 03 12

External ShocksExternal Shocks External shocks are shocks between the External shocks are shocks between the

relativistic ejecta and the ISM - just like relativistic ejecta and the ISM - just like in SNRs. Can be produced by a single in SNRs. Can be produced by a single explosion.explosion.

Page 13: PASCOS 031 Gamma Ray Bursts – The Brightest Explosions in the Universe Tsvi Piran Hebrew University, Jerusalem  W. Benz  M. Davies  David Eichelr

PASCOS 03Tsvi Piran HU 13

A NO GO THEOREMA NO GO THEOREM

External shocks cannot External shocks cannot produce a variable light produce a variable light

curve!!!curve!!! (Sari & Piran 97)(Sari & Piran 97)

Page 14: PASCOS 031 Gamma Ray Bursts – The Brightest Explosions in the Universe Tsvi Piran Hebrew University, Jerusalem  W. Benz  M. Davies  David Eichelr

PASCOS 03Tsvi Piran HU 14

Implication: Typical* Implication: Typical* GRBs GRBs cannot originate from a cannot originate from a

single single EXPLOSIONEXPLOSION..This rules out many models:This rules out many models:

•Evaporating mini black holes.Evaporating mini black holes.

•Discharge of a charged BHDischarge of a charged BH

•NS -> strange starNS -> strange star

•Vacuum InstabilityVacuum Instability

•……………………..

* * Highly variable (there is a small group of Highly variable (there is a small group of smooth bursts which can be explosive)smooth bursts which can be explosive)

Page 15: PASCOS 031 Gamma Ray Bursts – The Brightest Explosions in the Universe Tsvi Piran Hebrew University, Jerusalem  W. Benz  M. Davies  David Eichelr

PASCOS 03 15

• =R=R//cc==//cc//cc=T=T• The observed light curve The observed light curve

reflects the activity of the reflects the activity of the “inner engine”. “inner engine”. Need TWO time scales.

• To produce internal shocks To produce internal shocks the source must be active the source must be active and highly variable over a and highly variable over a

“long” period.“long” period.

=cT=cT

==cT

Internal ShocksInternal ShocksShocks between different Shocks between different shells of the ejected shells of the ejected relativistic matterrelativistic matter

TT

Page 16: PASCOS 031 Gamma Ray Bursts – The Brightest Explosions in the Universe Tsvi Piran Hebrew University, Jerusalem  W. Benz  M. Davies  David Eichelr

PASCOS 03 16

• Internal shocks can convert only a fractionInternal shocks can convert only a fraction of of the kinetic energy to radiationthe kinetic energy to radiation

(Sari and Piran 1997; Mochkovich et. al., 1997; (Sari and Piran 1997; Mochkovich et. al., 1997; Kobayashi, Piran & Sari 1997).Kobayashi, Piran & Sari 1997).

It should be followed by additional emissionIt should be followed by additional emission..

““It ain't over till it's over” (Yogi Berra)It ain't over till it's over” (Yogi Berra)

=cT=cT

==cT

Internal Internal Shocks Shocks AfterglowAfterglow

Page 17: PASCOS 031 Gamma Ray Bursts – The Brightest Explosions in the Universe Tsvi Piran Hebrew University, Jerusalem  W. Benz  M. Davies  David Eichelr

PASCOS 03 17

1)1) Compact Source, E>10Compact Source, E>105151ergerg

2) Relativistic Kinetic Energy2) Relativistic Kinetic Energy

3) 3) Radiation due to Internal shocks = GRBsRadiation due to Internal shocks = GRBs

4) Afterglow by external shocks4) Afterglow by external shocks

The Central Compact Source is HiddenThe Central Compact Source is Hidden

Gamma-Ray Burst: 4 Stages

Page 18: PASCOS 031 Gamma Ray Bursts – The Brightest Explosions in the Universe Tsvi Piran Hebrew University, Jerusalem  W. Benz  M. Davies  David Eichelr

InnerEngine

Relativistic Wind

The Internal-External Fireball ModelThe Internal-External Fireball Model

There are There are no direct observationsno direct observations of the inner engine. of the inner engine.The The -rays light curve-rays light curve contains the contains the best evidencebest evidence on on the inner engine’s activity.the inner engine’s activity.

ExternalShock

Afterglow

InternalShocks

-rays

Page 19: PASCOS 031 Gamma Ray Bursts – The Brightest Explosions in the Universe Tsvi Piran Hebrew University, Jerusalem  W. Benz  M. Davies  David Eichelr

PASCOS 03 19

GRB - The MovieGRB - The MovieFour Initialshells

ISM

Afterglow - other colors

GRB -yellow flash

Page 20: PASCOS 031 Gamma Ray Bursts – The Brightest Explosions in the Universe Tsvi Piran Hebrew University, Jerusalem  W. Benz  M. Davies  David Eichelr

PASCOS 03Tsvi Piran HU 20

THE FIREBALL MODEL PREDICTED GRB

AFTERGLOW (late emission in lower wavelength that will

follow the GRB)

Rhodas & Paczynksi, Katz, Meszaros Rhodas & Paczynksi, Katz, Meszaros & Rees, Waxman, Vietri, Sari & Piran & Rees, Waxman, Vietri, Sari & Piran

Page 21: PASCOS 031 Gamma Ray Bursts – The Brightest Explosions in the Universe Tsvi Piran Hebrew University, Jerusalem  W. Benz  M. Davies  David Eichelr

PASCOS 03 21

1997: Afterglow – 1997: Afterglow – The Second RevolutionThe Second Revolution

The Italian/Dutch The Italian/Dutch

satellitesatellite BeppoSAXBeppoSAX

discovered x-ray afterglowdiscovered x-ray afterglow

on 28 February 1997on 28 February 1997

(Costa et. al. 97)(Costa et. al. 97). . Immediate discovery of Immediate discovery of OpticalOptical

afterglow afterglow (van Paradijs et. al 97).(van Paradijs et. al 97).

Page 22: PASCOS 031 Gamma Ray Bursts – The Brightest Explosions in the Universe Tsvi Piran Hebrew University, Jerusalem  W. Benz  M. Davies  David Eichelr

PASCOS 03 22

The Radio AfterglowThe Radio Afterglow of of GRB970508 GRB970508 (Frail et. al, 97).(Frail et. al, 97).

Variability:Variability: * * Scintillations Scintillations (Goodman, 97; Frail Kulkarni & Waxman 97)(Goodman, 97; Frail Kulkarni & Waxman 97)

Size afterSize after one month ~10one month ~101717cm.cm. Rising Spectrum at low frequencies:Rising Spectrum at low frequencies:

Self absorptionSelf absorption ( (Katz & Piran, 97; Frail et al 97Katz & Piran, 97; Frail et al 97)) Size after one month Size after one month ~ 10~ 101717cmcm..

Relativistic Motion!!! Relativistic Motion!!! (but (but since this is a long time after the explosionsince this is a long time after the explosion

Page 23: PASCOS 031 Gamma Ray Bursts – The Brightest Explosions in the Universe Tsvi Piran Hebrew University, Jerusalem  W. Benz  M. Davies  David Eichelr

PASCOS 03 23

A crash Course in ScintillationsA crash Course in Scintillations

Scintillations determine the size of the source in a Scintillations determine the size of the source in a model independent way. The size (~10model independent way. The size (~101717cm) is in a cm) is in a perfect agreement with the prediction of the perfect agreement with the prediction of the Fireball model.Fireball model.

Page 24: PASCOS 031 Gamma Ray Bursts – The Brightest Explosions in the Universe Tsvi Piran Hebrew University, Jerusalem  W. Benz  M. Davies  David Eichelr

PASCOS 03 24

Afterglow TheoryAfterglow Theory

Hydrodynamics:Hydrodynamics: deceleration of thedeceleration of the

relativistic shell by collision with the surrounding mediumrelativistic shell by collision with the surrounding medium (Blandford & McKee 1976)(Blandford & McKee 1976) (Meszaros & Rees 1997, Waxman 1997, Sari 1997, Cohen, Piran & (Meszaros & Rees 1997, Waxman 1997, Sari 1997, Cohen, Piran & Sari 1998)Sari 1998)

Radiation:Radiation: synchrotron + IC (?)synchrotron + IC (?)

(Sari, Piran & Narayan 98)(Sari, Piran & Narayan 98)

Clean, well defined problem.Clean, well defined problem.

Few parameters:Few parameters:

E, n, p, E, n, p, ee, , BB

initialinitialshellshell ISMISM

Page 25: PASCOS 031 Gamma Ray Bursts – The Brightest Explosions in the Universe Tsvi Piran Hebrew University, Jerusalem  W. Benz  M. Davies  David Eichelr

PASCOS 03 25

Comparison with ObservationsComparison with Observations(Sari, Piran & Narayan 98; Wijers & Galama 98; Granot, (Sari, Piran & Narayan 98; Wijers & Galama 98; Granot,

Piran & Sari 98; Panaitescu & Kumar 02)Piran & Sari 98; Panaitescu & Kumar 02)

Radio observationsRadio observations

Radio to X-rayRadio to X-ray

Page 26: PASCOS 031 Gamma Ray Bursts – The Brightest Explosions in the Universe Tsvi Piran Hebrew University, Jerusalem  W. Benz  M. Davies  David Eichelr

PASCOS 03 26

The Early Afterglow and the The Early Afterglow and the Optical FlashOptical Flash

The late afterglow observations confirmed relativistic motion.The late afterglow observations confirmed relativistic motion. But what is the value of But what is the value of during the GRB phase? during the GRB phase? 100 < 100 < 0 0 = E= E00/M/M00 < 10 < 1055

““dirty” “clean”dirty” “clean” This could be tested This could be tested by early afterglow by early afterglow observationsobservations (Sari & (Sari & Piran: Rome, Oct 1998; Piran: Rome, Oct 1998; Astro-ph/11/1/1999):Astro-ph/11/1/1999):

A very strongoptical flashcoinciding withthe GRB

optical

x-rays

-rays

Page 27: PASCOS 031 Gamma Ray Bursts – The Brightest Explosions in the Universe Tsvi Piran Hebrew University, Jerusalem  W. Benz  M. Davies  David Eichelr

InnerEngine

Relativistic Wind

The Internal-External Fireball ModelThe Internal-External Fireball Model

ExternalShock

Afterglow

InternalShocks

-rays

OPTICAL FLASHOPTICAL FLASH

Page 28: PASCOS 031 Gamma Ray Bursts – The Brightest Explosions in the Universe Tsvi Piran Hebrew University, Jerusalem  W. Benz  M. Davies  David Eichelr

PASCOS 03 28

GRB 990123 - TheGRB 990123 - ThePrompt Optical FlashPrompt Optical Flash

ROTSE’s detection of a 9ROTSE’s detection of a 9thth magnitude magnitude prompt optical flash.prompt optical flash.

Page 29: PASCOS 031 Gamma Ray Bursts – The Brightest Explosions in the Universe Tsvi Piran Hebrew University, Jerusalem  W. Benz  M. Davies  David Eichelr

PASCOS 03 29

The Initial Lorentz FactorThe Initial Lorentz Factor The observations of early afterglow from GRB 990123 lead to several The observations of early afterglow from GRB 990123 lead to several

independent estimates of the initial Lorentz factor (Sari &Piran, independent estimates of the initial Lorentz factor (Sari &Piran, 1999):1999):

The afterglow begins after The afterglow begins after ~70~70 sec secii~200~200 mm the synchrotron frequency of the reverse shock, is below the the synchrotron frequency of the reverse shock, is below the

optical bandsoptical bands ii~200~200 The ratio The ratio m_forward m_forward / / m_reverse m_reverse ~ ~ ii

2 2 ii~70~70 This is the This is the first, and so far only,first, and so far only, direct measurement of the initial direct measurement of the initial

Lorentz factor. It is in agreement with opacity lower limits.Lorentz factor. It is in agreement with opacity lower limits. An indirect measurement of An indirect measurement of ~100 AU from a distance of 6Gpc!~100 AU from a distance of 6Gpc!

Page 30: PASCOS 031 Gamma Ray Bursts – The Brightest Explosions in the Universe Tsvi Piran Hebrew University, Jerusalem  W. Benz  M. Davies  David Eichelr

PASCOS 03 30

GRB EnergiesGRB Energies

EEtottot -- The total energy The total energy

EE--Observer Observer ray energyray energy

EEtot

1

Page 31: PASCOS 031 Gamma Ray Bursts – The Brightest Explosions in the Universe Tsvi Piran Hebrew University, Jerusalem  W. Benz  M. Davies  David Eichelr

PASCOS 03 31

The “Efficiency” FactorThe “Efficiency” Factor

45

47

49

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53

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59

1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002

Lo

g

( E )

Total EnergyTotal Energy

Page 32: PASCOS 031 Gamma Ray Bursts – The Brightest Explosions in the Universe Tsvi Piran Hebrew University, Jerusalem  W. Benz  M. Davies  David Eichelr

PASCOS 03 32

““Direct” Energy MeasurementsDirect” Energy MeasurementsIn bursts with afterglow for which the host galaxy In bursts with afterglow for which the host galaxy was observed we could estimate the total energy was observed we could estimate the total energy “directly” using the redshift of the host galaxy.“directly” using the redshift of the host galaxy.

GRB970508GRB970508 Z=0.865Z=0.865 5.5 105.5 105151

971214971214 3.4183.418 2.1 102.1 105353

980703980703 0.9660.966 6 106 105252

990123990123 1.61.6 1.4 101.4 105454

000131000131 4.54.5 1.2 101.2 105454

000418000418 1.1191.119 8.2 108.2 105252

000926000926 2.0372.037 3 103 105353

Page 33: PASCOS 031 Gamma Ray Bursts – The Brightest Explosions in the Universe Tsvi Piran Hebrew University, Jerusalem  W. Benz  M. Davies  David Eichelr

PASCOS 03Tsvi Piran HU 33

The Energy Crisis?

45

47

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1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002

Lo

g

( E )

(E)

971214971214 990123990123

Totani’s prediction for the energy of GRBs

Page 34: PASCOS 031 Gamma Ray Bursts – The Brightest Explosions in the Universe Tsvi Piran Hebrew University, Jerusalem  W. Benz  M. Davies  David Eichelr

PASCOS 03Tsvi Piran HU 34

How to explain 10How to explain 105454 ergs? ergs?

Once more (now in 1999) Once more (now in 1999) GRBs need new PhysicsGRBs need new Physics

Page 35: PASCOS 031 Gamma Ray Bursts – The Brightest Explosions in the Universe Tsvi Piran Hebrew University, Jerusalem  W. Benz  M. Davies  David Eichelr

PASCOS 03 35

The Resolution of the Energy CrisisThe Resolution of the Energy Crisis

EEtottot -- The total energy The total energy

EEisoiso--Observed (iostropic) Observed (iostropic) ray energyray energy

isotot EE 1

isotot EEE 2

211

Beaming:Beaming:EE- Actual - Actual ray energyray energy

The two most powerful BeppoSAX bursts are The two most powerful BeppoSAX bursts are jets (Sari, Piran & Halpern; 1999).jets (Sari, Piran & Halpern; 1999).

Page 36: PASCOS 031 Gamma Ray Bursts – The Brightest Explosions in the Universe Tsvi Piran Hebrew University, Jerusalem  W. Benz  M. Davies  David Eichelr

PASCOS 03 36

Jets are common in AGNJets are common in AGN

The jet from the core of M87The jet from the core of M87X-ray jet from the core of Cen AX-ray jet from the core of Cen A

Page 37: PASCOS 031 Gamma Ray Bursts – The Brightest Explosions in the Universe Tsvi Piran Hebrew University, Jerusalem  W. Benz  M. Davies  David Eichelr

PASCOS 03 37

JETS and BEAMINGJETS and BEAMING

Jets with an opening angleJets with an opening angle expand forwards until expand forwards until = = and then expand sideways and then expand sideways rapidly lowering quickly the observed flux rapidly lowering quickly the observed flux (Piran, 1995; Rhoads, 1997; Wijers et (Piran, 1995; Rhoads, 1997; Wijers et al, 1997; Panaitescu & Meszaros 1998).al, 1997; Panaitescu & Meszaros 1998).

Particles spreadssidewaysquickly

Radiationis “beamed”into a large cone

Particles remainwithin initial cone

Radiation is “beamed” intoa narrow cone

Page 38: PASCOS 031 Gamma Ray Bursts – The Brightest Explosions in the Universe Tsvi Piran Hebrew University, Jerusalem  W. Benz  M. Davies  David Eichelr

PASCOS 03 38

GRB II - The SequelGRB II - The Sequel

Four Initialshells

ISM

Afterglow - other colors

GRB -yellow flash

Page 39: PASCOS 031 Gamma Ray Bursts – The Brightest Explosions in the Universe Tsvi Piran Hebrew University, Jerusalem  W. Benz  M. Davies  David Eichelr

PASCOS 03 39

GRB 990510 - GRB 990510 - The best Jet!The best Jet!

ttbreakbreak = 1.2 days = 1.2 days jet angle = 4 jet angle = 4o o FromFrom Harrison et al 1999Harrison et al 1999

Page 40: PASCOS 031 Gamma Ray Bursts – The Brightest Explosions in the Universe Tsvi Piran Hebrew University, Jerusalem  W. Benz  M. Davies  David Eichelr

PASCOS 03 40

Page 41: PASCOS 031 Gamma Ray Bursts – The Brightest Explosions in the Universe Tsvi Piran Hebrew University, Jerusalem  W. Benz  M. Davies  David Eichelr

PASCOS 03 41

A Sharp A Sharp (Not Achromatic)(Not Achromatic) Break!Break!

* * synch emission does not include the effects of cooling.synch emission does not include the effects of cooling.

Page 42: PASCOS 031 Gamma Ray Bursts – The Brightest Explosions in the Universe Tsvi Piran Hebrew University, Jerusalem  W. Benz  M. Davies  David Eichelr

PASCOS 03Tsvi Piran HU 42

The Energy Crisis?The Energy Crisis?

45

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1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002

Lo

g

( E )(E

)

971214971214 990123990123

Prediction for the energy of GRBs

What goes What goes up must up must go down go down

e.g. e.g. NASDAQNASDAQ

Page 43: PASCOS 031 Gamma Ray Bursts – The Brightest Explosions in the Universe Tsvi Piran Hebrew University, Jerusalem  W. Benz  M. Davies  David Eichelr

PASCOS 03 43

EEisoiso

EE(PK)(PK)

EE(F)(F)

EEKK(PK)(PK)

Energy Estimates Energy Estimates

Jimmenez Jimmenez et al et al

Afterglow Afterglow GRBsGRBs

SchmidtSchmidtAll All

GRBsGRBs

Page 44: PASCOS 031 Gamma Ray Bursts – The Brightest Explosions in the Universe Tsvi Piran Hebrew University, Jerusalem  W. Benz  M. Davies  David Eichelr

PASCOS 03 44

Redshift and Redshift and BeamingBeamingEnergy Energy DeterminationDetermination

GRBGRB ZZ E (E (×× 10 105151)) E (E (×× 10 105151))

970228970228 0.6950.695 22.422.4

970508970508 0.8350.835 5.465.46 .234.234

970828970828 0.9580.958 220220 .575.575

971214971214 3.4123.412 211211 >.333>.333

980613980613 1.0961.096 5.675.67 >.045>.045

980703980703 0.9670.967 60.160.1 .544.544

990123990123 1.61.6 1440 1.81.8

990506990506 1.31.3 854854

990510990510 1.6191.619 178178 .248.248

990705990705 0.840.84 270270 .389.389

990712990712 0.4330.433 5.275.27 >.455>.455

991208991208 0.7060.706 147147 <.455<.455

991216991216 1.021.02 535535 .695.695

000131000131 4.5 11601160 <1.3<1.3

000131c000131c 2.0342.034 46.446.4 .256.256

000418000418 1.1191.119 82.082.0 1.61.6

000926000926 2.0372.037 297297 .379.379

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Energy EstimatesEnergy Estimates• Frail et al, 01: EFrail et al, 01: E 5 5 10105050ergsergs FWHM ~ FWHM ~ 55• PK 01: PK 01: EE 7 7 10105050ergsergs FWHM ~ FWHM ~1111• PK 01: PK 01: EEKK 2 2 10105050ergsergs FWHM ~ FWHM ~ 22

(PK = Panaitescu & Kumar)(PK = Panaitescu & Kumar)• Piran, Kumar, PanaitescuPiran, Kumar, Panaitescu

& Piro: E& Piro: EKK FWHM < FWHM < 2.52.5

GRBs release a constant GRBs release a constant amount of energy ~10amount of energy ~105151 ergs!!! ergs!!!

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PASCOS 03Tsvi Piran HU 46

Implications of Implications of the Fireball the Fireball

ModelModel

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Clues on the Inner Engine Clues on the Inner Engine The inner source is hidden. The observations The inner source is hidden. The observations

reflect only the conditions at the fireball.reflect only the conditions at the fireball. EEtottot~ 10~ 105151 ergs ergs

< 10< 10-2-2 sec sec T ~ 30 secT ~ 30 sec

~ 200 (“dirty”)~ 200 (“dirty”) Jets ~ 2Jets ~ 2o o - 5- 5oo

Rate 10Rate 10-5-5 /yr/galaxy /yr/galaxy

A compact ObjectA compact Object A compact ObjectA compact Object Prolonged activity: Prolonged activity:

an accretion disk ?an accretion disk ? Baryonic Flow ?Baryonic Flow ? Lower energy, higher Lower energy, higher

rates, orphan afterglowsrates, orphan afterglows A rare phenomenonA rare phenomenon

Most likely powered by accretion onto a Most likely powered by accretion onto a newborn black holenewborn black hole

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Routes to a Routes to a BH-Disk-JetBH-Disk-Jet

Different routes can lead to Different routes can lead to a Black-hole -disk-jet a Black-hole -disk-jet system:system:

NS/BH-NS mergerNS/BH-NS merger BH-WD mergerBH-WD merger NS/BH-He core mergerNS/BH-He core merger CollapsarCollapsar

Davies et al , 94Davies et al , 94

Woosley et al, 99Woosley et al, 99

shortshort

LongLong

- LONG- LONG

- SHORT- SHORT

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PASCOS 03 49Woosley et al., 99Woosley et al., 99

NY Times May 99NY Times May 99

Roswog et al, 99Roswog et al, 99

Davies et al, 94Davies et al, 94

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Rates and DistancesRates and Distances

One One longlong GRBs per 10 GRBs per 104 4 ((/0.1)/0.1)-2 -2 years per galaxy. years per galaxy. Beaming factorBeaming factor

One observed long burst per year at D~600 One observed long burst per year at D~600 Mpc.Mpc. One One unobservedunobserved burst per year at D~135 burst per year at D~135 ((/0.1)/0.1) 2/3 2/3

Mpc.Mpc. ShortShort bursts are most likely at z<0.5 with one bursts are most likely at z<0.5 with one

short burst per 10short burst per 103 3 ((/0.1)/0.1)-2 -2 years per galaxy. years per galaxy. One observed One observed shortshort burst per year at D~250 Mpc. burst per year at D~250 Mpc. One One unobservedunobserved shortshort burst per year at burst per year at

D~80(D~80(/0.1)/0.1)2/32/3Mpc. Mpc.

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GRBs as Beacons for the GRBs as Beacons for the UniverseUniverse

GRBs follow the star formation rate.GRBs follow the star formation rate. GRBs and their afterglow can be detected GRBs and their afterglow can be detected

even from Z~10.even from Z~10. 10-25% of GRBs are from Z>5.10-25% of GRBs are from Z>5. GRBs are ideal beacons to explore the early GRBs are ideal beacons to explore the early

universe – at the time of “first light”.universe – at the time of “first light”.

Ly Ly clouds cloudsreionizationreionization

Star formation rateStar formation rate

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GRBs as Tests for Quantum GRBs as Tests for Quantum GravityGravity

Time delay between arrival of high energy Time delay between arrival of high energy photons and low energy photons can yield photons and low energy photons can yield significant limits of “Lorentz Violation” significant limits of “Lorentz Violation”

(Amelino-Camelia, Ellis,  Mavromatos, (Amelino-Camelia, Ellis,  Mavromatos, Nanopoulos, Sarkar, 97)Nanopoulos, Sarkar, 97)

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GRBs in the GalaxyGRBs in the Galaxy One GRB per 10One GRB per 1044 years: years:

Results in a double Results in a double bubble that might be bubble that might be distinguished (for ~1000 distinguished (for ~1000 years) from a regular years) from a regular SNR.SNR.

One GRB towards us One GRB towards us per10 per1066-10-1077 years: years: May lead to life May lead to life extinction on earth.extinction on earth.