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?
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-(-())/2/2
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
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
• 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
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)
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