Early and Late Prompt Early and Late Prompt emissionemission

Gabriele Ghisellini

INAF-Osservatorio Astronomico di Brera - Italy

++

UHECRs and MagnetarsUHECRs and Magnetars

with the help of D. Burlon, A. Celotti, C. Firmani, F. Fraternali, G.

Ghirlanda, D. Lazzati, L. Nava, M. Nardini, F. Tavecchio

Very early prompt: Very early prompt: PrecursorsPrecursors

Study of all Swift GRBs with z Study of all Swift GRBs with z

Initial pulse, weaker and Initial pulse, weaker and separated from the prompt separated from the prompt (i.e. BAT flux below bkg level)(i.e. BAT flux below bkg level)

Precursors in 15%Precursors in 15%Burlon+ astro-ph/0806.3076Burlon+ astro-ph/0806.3076

““Precursors”Precursors”

Very long Very long tt

DoublDoublee

Burlon+ 2008, Burlon+ 2008, astro-ph/0806.307astro-ph/0806.30766

Not softer, not harder Not softer, not harder than the rest of than the rest of

promptprompt

Very energetic (factor Very energetic (factor ~3 less than total)~3 less than total)

No correlation with delay timeNo correlation with delay time

>40s>40s

15-15-40s40s

<15s<15s

Slope Main Slope Main PromptPrompt

Slo

pe P

recu

rsor

Slo

pe P

recu

rsor

Energy Main Energy Main PromptPrompt

En

erg

y

En

erg

y

Pre

cu

rsor

Pre

cu

rsor

They look li

ke the fi

rst p

ulse o

f the

They look li

ke the fi

rst p

ulse o

f the

prom

pt, not a

separa

ted co

mponent.

Why

prom

pt, not a

separa

ted co

mponent.

Why

t so lo

ng?

t so lo

ng?

Late activityLate activity

X-ray and optical X-ray and optical oftenoften behave behave differentlydifferently

~same ~same spectrumspectrum

TTAA

Is this “real” afte

rglow? i.e. e

xternal

Is this “real” afte

rglow? i.e. e

xternal

shock?

shock?

X-ray

Nard

ini et

al.

, in

pre

p.

Nard

ini et

al.

, in

pre

p.

OpticalOptical

X-raysX-rays TTAA

TTAA??

What

is T

What

is T AA

? ?

Early (normal) prompt: Early (normal) prompt: >>1/j

Late prompt: Late prompt: >1/j

Late prompt: Late prompt: =1/j

Late prompt: Late prompt: <1/j

”real” after-glow

Ghisellini et al. Ghisellini et al. 20072007

Strong, Strong, erraticerraticSmoothSmooth

After the early After the early prompt, the central prompt, the central engine decreases engine decreases energy and decreases energy and decreases monotonicallymonotonically

R~10R~101313 cmcm

Early (normal) prompt: Early (normal) prompt: >>1/j

Late prompt: Late prompt: >1/j

Late prompt: Late prompt: =1/j

Late prompt: Late prompt: <1/j

”real” after-glow

Ghisellini et al. Ghisellini et al. 20072007R~10R~101313

cmcm

TTAA

TTjetjet

~ t~ t--/2/2tt--22

tt--33

TimTimee

Flu

xFlu

x

MMoutout ~ t ~ t-(-())/2/2TTAA

LLMMoutout ~ t ~ t--

~ t~ t--/2/2tt--22

tt--33

TimTimee

Flu

xFlu

x

MMoutout ~ t ~ t-(-())/2/2

Long lasting engine with two-phase Long lasting engine with two-phase accretion?accretion?1: Very dense torus, large B-field, 1: Very dense torus, large B-field, erratic.erratic.

2: Less dense material, smaller B-2: Less dense material, smaller B-field, smoother accretion – field, smoother accretion – Fallback?Fallback?

TTAA

LLMMoutout ~ t ~ t--

L~ ML~ Maccraccr ? ?

Very Very cheapcheap

MacFad

yen

+ 2

001

MacFad

yen

+ 2

001

tt-5/3-5/3M

fro

m f

allb

ack

Zh

an

g W

oosle

y H

eg

er

Zh

an

g W

oosle

y H

eg

er

2008

2008

106105104103

Time [s]

Fallback

lasts

for q

uite a lo

ng

Fallback

lasts

for q

uite a lo

ng

time

time

M f

rom

fa

llb

ack

Lazz

ati

+ 2

008

Lazz

ati

+ 2

008

tt-5/3-5/3

From averaging the luminosity of flares in From averaging the luminosity of flares in different GRBsdifferent GRBs

Lazz

ati

+ 2

008

Lazz

ati

+ 2

008

tt-5/4-5/4

From averaging the luminosity of flares in From averaging the luminosity of flares in different GRBsdifferent GRBs

~70 Swift GRBs ~70 Swift GRBs with zwith z

tt-5/3-5/3

tt-5/4-5/4

• SEDs vs light curvesSEDs vs light curves

TestsTests

Log

Log

FF

Log Log

opticaopticall

X-raysX-rays

• SEDs vs light curvesSEDs vs light curves• Some GRBs with no plateau: Some GRBs with no plateau:

achromatic breaks? achromatic breaks?

TestsTests

• SEDs vs light curvesSEDs vs light curves• Some GRBs with no plateau: Some GRBs with no plateau:

achromatic breaks? achromatic breaks? • Late ‘jump’ in X-ray light-curves Late ‘jump’ in X-ray light-curves

revealing real X-ray afterglowrevealing real X-ray afterglow

TestsTests

TTAA

Jump=end Jump=end of late of late promptprompt

TimeTime

X-r

ay

X-r

ay

Flu

xFlu

x

UHECRs, Spiral UHECRs, Spiral Galaxies and Galaxies and Magnetars Magnetars

with Ghirlanda, Tavecchio, Fraternali, Pareschiwith Ghirlanda, Tavecchio, Fraternali, Pareschi

astro—ph/0806.2393astro—ph/0806.2393

27 Auger Events >57 27 Auger Events >57 EeVEeV

Auger events

1 EeV=101 EeV=101818 eV eV

The Auger collaboration, 2007, ScienceThe Auger collaboration, 2007, Science

CenA

VirgoAGNs from VC-V catalogue

If the Galactic plane is excluded, 19 out of 21 events do correlate

Auger events

The Auger collaboration, 2007, ScienceThe Auger collaboration, 2007, Science

HIPASS: ~5000 HI emitting galaxies (21 cm) GG+, 2008GG+, 2008

Weight for flux Weight for flux and Auger and Auger exposureexposure

~72%

Cut in distance

Cut in luminosity

VirgoVirgo

CentaurCentaurusus

It is

not Cen A

, it i

s the C

entauru

s

It is

not Cen A

, it i

s the C

entauru

s

clust

er (>40 M

pc)

clust

er (>40 M

pc)

100 Mpc

FFAugerAuger ~ 10 ~ 10-11-11 erg cm erg cm22 s s-1-1 Flux for E>57 EeVFlux for E>57 EeV

Easy for AGNs (but they are radio-quiet… no Easy for AGNs (but they are radio-quiet… no ))

Long `BATSE’ GRBs (too distant)Long `BATSE’ GRBs (too distant)

Short `BATSE’ GRBs (flux not enough)Short `BATSE’ GRBs (flux not enough)

Giant Flares of Magnetars (flux not enough)Giant Flares of Magnetars (flux not enough)

Newly born, fastly spinning Magnetars (!!!, Newly born, fastly spinning Magnetars (!!!, but went unobserved by BATSE)but went unobserved by BATSE)

ProgenitorsProgenitors

Cam

pan

a e

t al.

20

06

Cam

pan

a e

t al.

20

06

BB FluxBB Flux

Opt-UVOpt-UV

GRB 060218 ???GRB 060218 ???

GRB 060218 ???GRB 060218 ???

• Very long, soft, underluminous, Very long, soft, underluminous, nearby (145 Mpc)nearby (145 Mpc)

• It could not have triggered It could not have triggered BATSEBATSE

• Proposed to be a newborn Proposed to be a newborn magnetar (Soderberg+ 2007; magnetar (Soderberg+ 2007; Toma+ 2007)Toma+ 2007)

• Right rate Right rate

ConclusionsConclusions

• Precursors? Same as prompt Precursors? Same as prompt just first just first pulse. Why so long quiescent times?pulse. Why so long quiescent times?

• Late prompt with decreasing power and Late prompt with decreasing power and • TTAA is very easily explained is very easily explained

• Fallback is long Fallback is long late prompt “forever” late prompt “forever”• UHECRs correlate with spirals UHECRs correlate with spirals newly newly

born magnetars? If so, new class of GRBs born magnetars? If so, new class of GRBs (2 per yr all sky): similar to GRB 060218: (2 per yr all sky): similar to GRB 060218: soft, very long, underluminous+SNsoft, very long, underluminous+SN

Very energeticVery energetic

Nard

ini et

al.

, in

pre

p.

Nard

ini et

al.

, in

pre

p.

X-raysX-rays

OpticalOptical