Cosmology with Cosmology with GRBsGRBsghirlanda@merate.mi.astro.itghirlanda@merate.mi.astro.it

--

OsservatorioOsservatorio

didi

BreraBrera

Giancarlo Giancarlo GhirlandaGhirlanda

In coll. withIn coll. with

Gabriele Gabriele GhiselliniGhisellini

DavideDavide

LazzatiLazzati

Claudio Claudio FirmaniFirmani

Vladimir AvilaVladimir Avila--ReeseReese

ELT –

Florence 2004

Prompt emission Prompt emission Afterglow emission Afterglow emission

• energiesenergies

> 10 > 10 keVkeV

• 1 1 ms to ms to 1 1 ks ks

•• high high varibility varibility

• energiesenergies

X,X,

OptOpt, IR, Radio, IR, Radio

•• days to months days to months

•• smooth powerlawsmooth powerlaw(s) (s)

GRBs are fast transient high energy sources @ cosmological distances

ELT –

Florence 2004

The standard The standard picturepicture

Γ

= 102 - 104 Γ

= 10 ↓

ELT –

Florence 2004

GRB 970228

Gamma ray position accuracy 2 deg!!Need arcmin accuracy to

1.

Identify the counterpart

2.

Follow the afterglow and measure the redshift

X ray afterglow indetification

OT spectrum

42 redshift

s /3000 GRBsGRBsGRBs

are are cosmological cosmological

Optical transient

ELT –

Florence 2004

42 GRBs with redshift

Assuming isotropyAssuming isotropy

ELT –

Florence 2004

GRB typical Fluence (i.e. time int. flux) is 10-8 – 10-4 erg/cm2

Huge isotropic Huge isotropic equivalent energyequivalent energy!!!!

Jet opening angleRelativistc beaming:

emitting surface ∝

1/Γ

Γ

↓

, Surf.↑

Jet Break ϑ ∼

1/Γ

Log(t)

Log(F)

Jet Jet effecteffect

ELT –

Florence 2004

GRB Jet GRB Jet measuremeasure

“Jet break”

Jet break time tbreak

Jet opening angle ϑ

ELT –

Florence 2004

““TrueTrue”” energeticsenergetics

Frail et

al. 2

001

Isotropic equivalent energyIsotropic equivalent energy

Etrue

= Eiso (1 –

cos ϑ)

Bloo

m e

t al. 20

03

ELT –

Florence 2004

GRB Peak Energy

Characteristic energy of most emitted photons

Prompt emission spectrumPrompt emission spectrum

GRB Spectrum

ELT –

Florence 2004

Isotropic energy [erg]

EEpp(1+z)=E(1+z)=Eisoiso0.40.4

28 GRB +2 XRF28 GRB +2 XRFAmat

i et

al. 2

002,

Amat

i et

al. 2

002,

Ghirlan

daGh

irland

aet

al. 2

004

et a

l. 2

004

11--cos(cos(θθ))??031203

ttjet,djet,d

((ηηγγ

n)n)

uniform n, 1<n<10 if unknown uniform n, 1<n<10 if unknown

1 1 keVkeV

––

10 10 MeVMeV

ηηγγ=0.2=0.2

3/83/8 1/81/8θθ==0.160.16

(1+z)(1+z) EE

γ,γ,iso,52iso,521/81/83/83/8

ELT –

Florence 2004

Ghirland

aGh

irland

a , , Gh

isellin

iGh

isellin

i & & La

zzat

iLa

zzat

i 200

420

04χχrr

22=1.27=1.27

EE peak

peak=k

E=k

E γγ0.

706

0.70

6

ELT –

Florence 2004

EEpeakpeak

––

EEtruetrue

correlationcorrelation

Ghirland

aGh

irland

a , , Gh

isellin

iGh

isellin

i & & La

zzat

iLa

zzat

i 200

420

04ELT –

Florence 2004

Similar to Supernovae Similar to Supernovae IaIa

““StretchingStretching””: : the slower the slower

the brighterthe brighter

ELT –

Florence 2004

Ghirland

aGh

irland

a , , Gh

isellin

iGh

isellin

i , , L

azza

tiLa

zzat

i & & Fi

rman

iFi

rman

i 200

420

04

Luminos

ity

dist

ance

Luminos

ity

dist

ance

E=10E=105151

ergerg

redshiftredshift

ELT –

Florence 2004redshiftredshift

Luminos

ity

dist

ance

Luminos

ity

dist

ance

Luminos

ity

dist

ance

Luminos

ity

dist

ance

E=10E=105151

ergerg

χχrr22==2.92.9

χχrr22==1.321.32

ELT –

Florence 2004

1.5 -1.5

ELT –

Florence 2004

0.2 -

0.1

ELT –

Florence 2004

Ghirland

aGh

irland

a , , Gh

isellin

iGh

isellin

i , , L

azza

tiLa

zzat

i & & Fi

rman

iFi

rman

i 200

420

04

Consistent with Consistent with WMAP: WMAP:

ΩΩMM=0.3, =0.3, ΩΩΛΛ

=0.7=0.7

1515156156

GRB+SNGRB+SN

ELT –

Florence 2004

Firm

ani

Firm

ani , , G

hise

llini

Ghisellin

i , , G

hirlan

daGh

irland

a&

Avila

& Avila-- R

eese

, 20

04Re

ese,

200

4Flat UniverseFlat Universe: : ΩΩtottot=1=1

P=wP=w00

ρρcc22

transition z: transition z: a = 0a = 0

ELT –

Florence 2004

Firm

ani

Firm

ani , , G

hise

llini

Ghisellin

i , , G

hirlan

daGh

irland

a&

Avila

& Avila-- R

eese

, 20

04Re

ese,

200

4Flat UniverseFlat Universe: : ΩΩtottot=1,=1,

ΩΩMM

=0.27=0.27

P=(wP=(w00

+w+w’’z)z)ρρcc22

ELT –

Florence 2004

FirmaniFirmani, , GhiselliniGhisellini, , GhirlandaGhirlanda,& Avila,& Avila--Reese, 2004Reese, 2004Sw

iftSw

iftELT –

Florence 2004

In the Swift era:In the Swift era:FluencesFluences

not strongly dependent on znot strongly dependent on z

Early afterglow very well monitoredEarly afterglow very well monitored

Hope for small errors even at highHope for small errors even at high--zzXRFXRF

XRFXRF

ELT –

Florence 2004

Simulation for 150 Simulation for 150 ““Swift burstsSwift bursts””

150

ELT –

Florence 2004

ttbreakbreak=0.3d=0.3d

……

the the latest latest GRB GRB ……

ELT –

Florence 2004

`

Updated Correlation Updated Correlation

Updated cosmological constraintsUpdated cosmological constraints

www.merate.mi.astro.it/~ghirla/deep/blink.htmlwww.merate.mi.astro.it/~ghirla/deep/blink.html

ELT –

Florence 2004

High High redshift GRBs redshift GRBs and and ttbreakbreak

Z=10Z=10

Z=1Z=1

ttbreakbreak

=11 =11 daysdays

FF∝∝tt--1 1 forfor t<t<ttbreakbreak

FF∝∝tt--2 2 forfor t>t>ttbreakbreak

@ z=1@ z=1

ttbreakbreak = 2 = 2 days days

H H ≈≈

19 @ 1 day 19 @ 1 day

Typical Typical AfterglowAfterglow

ttbreakbreak

=2 =2 daysdays

VLTVLT

ELTELT

ELT ELT is mandatory to is mandatory to measure measure the jet break the jet break time of high z time of high z GRBsGRBs

ELT –

Florence 2004

Cosmology with Cosmology with high z high z GRBsGRBs

15 15 GRBs GRBs ((present samplepresent sample) ) 0.1 < z < 3.20.1 < z < 3.2

++

10 10 GRBs GRBs

9 < z < 109 < z < 10

ELT –

Florence 2004

ConclusionsConclusions

••

GRBsGRBs

areare

amongamong

the the most powerful sources most powerful sources of the of the universe universe and through the GGL04 and through the GGL04 correlation correlation can can be used be used as cosmological rulersas cosmological rulers..

••

GRBsGRBs

((detectable detectable out out to to z=17)z=17)

representrepresent

thethe

link link betweenbetween

SN Ia and CMBSN Ia and CMB

primary anysotropiesprimary anysotropies, and , and allows to allows to study study the the Universe geometry Universe geometry and and dynamicsdynamics..

••

RequirementsRequirements: : accurate accurate measure measure of of ttbreakbreak

+ + inclusion inclusion of of very very high high redshiftredshift

GRBsGRBs. At z > 6. At z > 6--7 7 need for Extramely need for Extramely Large TelescopesLarge Telescopes. .

••

ELTELT

high res. high res. Imaging Imaging can can also contribute also contribute in in understanding understanding the GRB the GRB progenitorprogenitor

nature, nature, emissionemission

processprocess

nature, GRB nature, GRB dynamicsdynamics

••

ELTELT

high res. high res. Spectroscopy Spectroscopy can can contribute contribute in in understanding understanding the GRB the GRB environsenvirons, , galaxygalaxy

populationpopulation..

ELT –

Florence 2004

041006041006

windwind

Ghirland

aGh

irland

a , , Gh

isellin

iGh

isellin

i , , L

azza

tiLa

zzat

i & & Fi

rman

iFi

rman

i 200

420

04

Spheres or jets?Spheres or jets?

“Jet break”

The fireball decelerates1/Γ

opens up

EEisoiso --

EE““truetrue””

EE““truetrue””

= = EEisoiso

(1(1--coscosθθjetjet))

θθjetjet

ttbreakbreak

measures measures θθjetjet

Structured jets?Structured jets?

θviewview

θjetjet

E(θ)=const

E(θ)=E0

θ-2

smoothsmooth bumpybumpy

Firm

aniet

al. 2

004

LL--1.5+1.5+--0.050.05

Universal Universal EEpeakpeak??Pr

eece

et a

l.~200 ~200 keVkeV, , observerobserver

frameframe

BATSEBATSE

HETE IIHETE II

0 0

2

2

ΩΩΛΛ

ΩΩ MM

z=1z=1dL

The cosmic whirlThe cosmic whirl

ttbreakbreak

θθ