GRBs with GLAST Tsvi Piran Racah Inst. of Jerusalem, Israel Yizhong Fan, Ramesh Narayan D. M. Wei

Tsvi Piran First GLAST Symposium

GRBs with GLASTGRBs with GLAST

Tsvi PiranTsvi PiranRacah Inst. of Jerusalem, IsraelRacah Inst. of Jerusalem, Israel

Yizhong Fan, Ramesh NarayanYizhong Fan, Ramesh Narayan D. M. WeiD. M. WeiMaria Rodriguez Martinez; Yonathan Oren; Uri Jacob Maria Rodriguez Martinez; Yonathan Oren; Uri Jacob


Observations (EAGRET)Observations (EAGRET)

GRB 940217GRB 940217

(Hurley et al. 1994)(Hurley et al. 1994)

GRB 930131 (Superball Burst)GRB 930131 (Superball Burst)


Observations (EAGRET):Observations (EAGRET): GRB 941017: Gonzalez et al. 2003GRB 941017: Gonzalez et al. 2003


Observations (MILAGRITO):Observations (MILAGRITO): GRB 970417a:GRB 970417a: Atkins et al., 00,03Atkins et al., 00,03

>3s>3s detection detection EETevTev > 10 E > 10 Eg g


Additional ObservationsAdditional Observations

• Upper limits from Magic for several Swift Upper limits from Magic for several Swift bursts bursts (Albert et al., 06, see also poster)(Albert et al., 06, see also poster)

• Claims of detection GRAND at 2.7 σ Claims of detection GRAND at 2.7 σ (Poirier (Poirier

et al 03, but see Fragile etal 03et al 03, but see Fragile etal 03))

• Tibet array: 7σ coincidence ? Tibet array: 7σ coincidence ? (Amenomori et al (Amenomori et al 01)01)

• ARGO-YBJ array find only upper limits ARGO-YBJ array find only upper limits (Di Sciascio, et al., 06)(Di Sciascio, et al., 06)


What is happening on the 17ths ?

• 940217 – GeV EGRET.• 941017 – 0.2 GeV –

TASC on EGRET• 970417 – TEV Milagrito

High Energy EventsHigh Energy Events


Relativistic Outflow

The Internal-External Fireball ModelThe Internal-External Fireball Model

InternalShocks

-rays

10101313-10-101515cmcm

InnerEngine

101066cmcm

ExternalShock

Afterglow

10101616-10-101818cmcm


SSCSSC

PromptPrompt SSCSSC

Forward Forward ShockShock SSCSSC

ee≈1000≈1000 ee≈1000≈1000 ee≈10≈1055-10-1033

ReverseReverse Shock Shock

SSCSSC

SSCSSCSynch Synch EnergyEnergy

Electron’s Electron’s Lorentz Lorentz FactorFactor

SSCSSC

energyenergy

DurationDuration

PromptPrompt 100 keV100 keV 10001000 100GeV100GeV PromptPrompt

Reverse Reverse ShockShock

0.1 eV0.1 eV 10001000 100MeV100MeV ShortShort

ForwardForward

ShockShock

10keV-10keV-1eV1eV

101055-10-1033 100TeV-100TeV-MeVMeV

LongLong

M’esz’aros & Rees 94; Pilla & Leob 98; Waxman & Pe’er 04, Granot & Guetta M’esz’aros & Rees 94; Pilla & Leob 98; Waxman & Pe’er 04, Granot & Guetta 03; Kobayashi et al. 07; Dermer, Chiang & Mitman03; Kobayashi et al. 07; Dermer, Chiang & Mitman00; Sari & Esin 01; Zhang & Mészáros 01)00; Sari & Esin 01; Zhang & Mészáros 01)


Reverse Reverse ShockShockEICEIC

Prompt InternalPrompt InternalShocksShocks

External IC External IC


Forward Forward ShockShockEICEIC

External IC External IC

ReverseReverse Shock Shock SynchSynch


External ICExternal IC elns elns

PhotonsPhotons


Forward Forward ShockShock

Internal Internal shocksshocks

100keV 100keV →→ 100GeV100GeV

ShortShort

0.1-10keV0.1-10keV

→→ Sub GeV Sub GeV - TeV - TeV

ShortShort


-------- 0.1eV 0.1eV →→

100 MeV100 MeV

ShortShortBeloborodov 05; Fan, Zhang & Wei 05; Fan & Piran 06; Fan et Beloborodov 05; Fan, Zhang & Wei 05; Fan & Piran 06; Fan et al., 07)al., 07)


FlaresFlares

GRB 050904 (Watson et al. 2006)GRB 050904 (Watson et al. 2006)GRB 050502b (Burrows et al. GRB 050502b (Burrows et al.

2005)2005)

Long-activity of the central engine (Fan & Wei 2005; Burrows et al. 2005; Zhang et al. 2006)

Or refreshed shocks (Piro et al., 2005)


Forward Forward ShockShockEICEIC

Late InternalLate InternalShocks (Flares)Shocks (Flares)


Flare ICFlare ICSynch Synch EnergyEnergy

Electron’s Electron’s Lorentz Lorentz FactorFactor

ICIC

energyenergy

Internal Internal Shocks Flare Shocks Flare SSCSSC

Refreshed Refreshed shocks SSCshocks SSC

1-10 keV1-10 keV 100100 10-100 10-100 MeVMeV

(but GeV is (but GeV is possible)possible)

Internal Internal Shocks Flare Shocks Flare EICEIC

.1-10 keV.1-10 keV 1000 1000 Sub GeV Sub GeV - TeV- TeV

Wei, Yan & Fan 06; Wang, Li & Meszaros 06; Wei, Yan & Fan 06; Wang, Li & Meszaros 06; Galli, Piro et al 06Galli, Piro et al 06 Fan, Piran, Narayan Fan, Piran, Narayan & Wei 07 & Wei 07


Flare- shock InteractionFlare- shock Interaction(Wang et al. 06 Fan & Piran 06; Fan et al. 007)(Wang et al. 06 Fan & Piran 06; Fan et al. 007)


The high energy spectrumThe high energy spectrum (Fan & Piran 2006; Fan , Piran, Narayan & Wei 2007)(Fan & Piran 2006; Fan , Piran, Narayan & Wei 2007)


Long-lasting X-ray flatteningLong-lasting X-ray flattening

GRB 060729 (astro-ph/0611240)GRB 060729 (astro-ph/0611240)

Possible interpretations • Energy injection• Increasing ee• ??


Swift early X-ray light curvesSwift early X-ray light curves

?Missing Emission?

Dark Emission

110,,

, hisok

isoobs

E

E


Constraining the physical processes Constraining the physical processes (Fan , Piran, Narayan & Wei 2007)(Fan , Piran, Narayan & Wei 2007)

Energy injectionEnergy injection vs.vs. Variable efficeincyVariable efficeincy

.e1

kcq ttE


A schematic high energy afterglow light curve A schematic high energy afterglow light curve (Fan , Piran, Narayan & Wei 2007)(Fan , Piran, Narayan & Wei 2007)

??


Further complications are possibleFurther complications are possibleand even likelyand even likely

In some GRBs, the optical and X-In some GRBs, the optical and X-ray afterglows break chromatiray afterglows break chromatically cally (Fan & Piran, 2006, Panaitesc(Fan & Piran, 2006, Panaitescu et al. 2006).u et al. 2006).

A drastic solution is that the two A drastic solution is that the two should be attributed to differeshould be attributed to different physical processes from diffnt physical processes from different regions erent regions (Fan & Wei 2005; P(Fan & Wei 2005; Piran & Fan 2007)iran & Fan 2007)

There are further indications supThere are further indications supporting this possibility (e.g. Gporting this possibility (e.g. GRB 060218, 070110)RB 060218, 070110)

This will lead to additional EIC pThis will lead to additional EIC processes! A possibity that coulrocesses! A possibity that could be tested by GLAST.d be tested by GLAST.


Additional ProcessesAdditional Processes

• pp → …+ pp → …+ →…+ →…+ Katz 94,Katz 94, … …

• pγpγ EM cascade EM cascade Boettcher & Dermer 98, Dermer, Boettcher & Dermer 98, Dermer, Atoyan 03, Dermer, Atoyan 04Atoyan 03, Dermer, Atoyan 04

• Neutronic Processes: np → .. + Neutronic Processes: np → .. + →…+ →…+

etc… etc… Razzaque & Mészáros, 06Razzaque & Mészáros, 06

-rays-rays AfterglowAfterglow

•ProgenitorProgenitor

•Energy generationEnergy generation

•Accretion?Accretion?

•Magnetar?Magnetar?

•Blandford ZnajekBlandford Znajek

•Acceleration & Collimation Acceleration & Collimation

•Source of variabilitySource of variability

•Continued activityContinued activity

• Nature of the Nature of the outflow outflow

•BaryonicBaryonic

•neutronsneutrons??

•Poynting fluxPoynting flux

•Collisionless Shocks Collisionless Shocks or Instabilities?or Instabilities?

•Particle AccelerationParticle Acceleration

•Radiation Processes Radiation Processes

•SynchSynch

•Inverse ComptonInverse Compton

•Magnetic Field Magnetic Field GenerationGeneration

•Jet Jet structure structure and and sideways sideways expansionexpansion


Conclusions IConclusions I• Very High Energy emission is expected from GRBs bVery High Energy emission is expected from GRBs b

oth from the prompt phase and from the afterglow oth from the prompt phase and from the afterglow phase. phase.

• This emission is likely to be detected by GLAST (see This emission is likely to be detected by GLAST (see several poster for estimates of rates of events). several poster for estimates of rates of events).

• The emission would carry a wealth of information oThe emission would carry a wealth of information on the GRBs (in particular on the Baryonic content of n the GRBs (in particular on the Baryonic content of the outflow). the outflow).

• However, as there are so many options it However, as there are so many options it might be difficult to figure out from non – might be difficult to figure out from non – detalied observations what was the detalied observations what was the radiation’s origin. radiation’s origin.


GBM SpectroscopyGBM Spectroscopy

• The GBMs Spectral ability (8 keV – The GBMs Spectral ability (8 keV – 20MeV) will provide information on the 20MeV) will provide information on the GRBs’ high energy spectrum which could GRBs’ high energy spectrum which could answer open questions like:answer open questions like:– The Amati Relation?The Amati Relation?– The existence of a hard burst population? The existence of a hard burst population?


Quantum Gravity with GRBsQuantum Gravity with GRBs(Amelino-Camelia et al., 98, Norris et al., 99, Ellis et al., 00,06, (Amelino-Camelia et al., 98, Norris et al., 99, Ellis et al., 00,06,

Amelino-Camelia and Piran, 02, Boggs 04, Martinez-Rodriguez et Amelino-Camelia and Piran, 02, Boggs 04, Martinez-Rodriguez et la., 06)la., 06)

• Lorentz Violation (or deformation) appears in various Lorentz Violation (or deformation) appears in various Quantum Gravity Theories.Quantum Gravity Theories.

Energy dependent dispersion and speed of light. Low Energy dependent dispersion and speed of light. Low energy approximation:energy approximation:

n

pl

n

pl

m

Encv

m

EpcE

2

)1(1

1)( 22

http://www.parmaq.com/BladePro/Images/honeycomb.gif


1

γ2

Energy dependent arrival time Energy dependent arrival time (Amelino-Camelia et al., 1998)(Amelino-Camelia et al., 1998)

http://glast.sonoma.edu/resources/multimedia/gallery/images/gsatellite.jpg


xx(2

)(2

) =10=10-1

2-1

2

xx(2

)(2

) =10

=10-

7-7

xx(2

)(2

) =10=10-2-2

xx(1)(1) =1=1

xx(1)(1) =0.01=0.01

GRB GRB photonsphotons

GRB neutrinosGRB neutrinos

101066 101088 10101010 10101212 10101414 10101616 10101818

E/eVE/eV

1010-6-6

101066

0.0010.001

11

10001000

Dt (sec)Dt (sec)

High High Energy Energy GRB GRB photonsphotons


RHESSI observations of GRB021206RHESSI observations of GRB021206

7.8 msec Bins7.8 msec Bins

RHESSI light curves of RHESSI light curves of GRB 021206GRB 021206

DtDt20keV-20MeV20keV-20MeV

< 7.8 msec< 7.8 msec

xx(1)(1) > 0.018 > 0.018

EE(1)(1)LVLV>> 1.8 101.8 101717 GeV GeV

xx(2)(2) > 4.5 10 > 4.5 10-12-12

EE(2)(2)LVLV> 4.5 10> 4.5 1077 GeV GeV

(assuming z=0.3)(assuming z=0.3)


Swift and Konus-Wind observations Swift and Konus-Wind observations of GRB051221Aof GRB051221A

SwiftSwift

Konus-WindKonus-Wind

DtDt16keV-300keV16keV-300keV

< 2 msec< 2 msec

xx(1)(1) > 0.0066 > 0.0066

EE(1)(1)LVLV>> 6.6 106.6 101616 GeV GeV

xx(2)(2) > 5 10 > 5 10-13-13

EE(2)(2)LVLV> 5 10> 5 1066 GeV GeV

Z=0.5465Z=0.5465


Conditions for DetectionConditions for Detection

n

statistics

statisticsrinsic

Edt

dEFlux

dt

dtdtdtt

2

expint

1

Use GBM for n=1 and LAT for n=2 and higherUse GBM for n=1 and LAT for n=2 and higher


Conclusions IIConclusions II• Gamma Ray Observations could shed light on Gamma Ray Observations could shed light on

possible Quantum Gravity induced Lorentz vipossible Quantum Gravity induced Lorentz violation (Energy dependent speed of light). olation (Energy dependent speed of light).

• Already now GRBs timing give the best limits Already now GRBs timing give the best limits on the scale of possible Lorentz violation: on the scale of possible Lorentz violation: EE(1)(1)

LVLV> 10> 101717 GeV GeV • Surprisingly distance and high energy do not Surprisingly distance and high energy do not

work in favor of a better limit for n=1. GBM wwork in favor of a better limit for n=1. GBM will have a major role here. ill have a major role here.

• High energy photons are important for n ≥ 2. High energy photons are important for n ≥ 2. LAT will provide the best limit on these modeLAT will provide the best limit on these models.ls.

Documents

GRBs with GLAST Tsvi Piran Racah Inst. of Jerusalem, Israel Yizhong Fan, Ramesh Narayan D. M. Wei