Blazar observation and
extragalatic absorption
Denis Bastieri
& Antonio Saggion
Blazars – Optical depth and flux calculation
dt
x
3  u n  z 
  E0 , ze   c  dz  dx  dn1  z  
s  s  2 E0 hnx1  z 

dz 0 2 0
 hn 
0
ze
2

E0: -energy (z = 0).
t(z): cosmic time:
dt/dz = H0–1(1+z)–5/2. h0 = 0.75.
ze: redshift of the source
x = (1 – cosJ), J scattering angle
n: bkg frequency at redshift z
s: cross section   e+e–
Numerical integration
qgauss of Num. Recipes
F   E   

E
dF  E 
dE
e
dE
with dF/dE = A×E–
[dF/dE] =  cm–2s–1GeV–1
IR-photon dependence via
a density table
 easy update
D. Bastieri: Flux extrapolation – GLAST s/w meeting – Udine, Jan. 31st 2003.
2
Blazars – The photon density
Data from the homepage
of Tanja Kneiske
http://www.astro.uni-wuerzburg.de/~kneiske/
D. Bastieri: Flux extrapolation – GLAST s/w meeting – Udine, Jan. 31st 2003.
3
Blazars – Significativity calculation
α
A
z
Flux
Li & Ma
Integration in log10(E[GeV])
log10(ΔEi) = [1, 1.1] … [3.9, 4]
QF S
T
2 N
200
1
 S T
6
s
Φ(Ei, θi) in γ/cm2
RA
dec
Novas
Obs. time in ZA bins
Δθi = [0, 5] … [65, 70]
obs.time/night > 10 min
Trigger
10/3
Aeff
γ detectable
by Magic
<F> (Hz)
D. Bastieri: Flux extrapolation – GLAST s/w meeting – Udine, Jan. 31st 2003.
Sigma
Ts5 
900 s
2
F
4
EGRET – Markarian 421
Source name
& source flux
cm–2s–1GeV–1
Observability
inset:
hours/1year
ZA bins.
Unabsorbed
flux
Sensitivity
data
D. Bastieri: Flux extrapolation – GLAST s/w meeting – Udine, Jan. 31st 2003.
Flux
interacting
with IR
5
EGRET – 3c279
MAGIC should
evidence the
internal cutoff
of FSRQ: foreseen in many
models around
100 GeV.
Costamante &
Ghisellini
“TeV candidates
BL Lac objects.”
astro/ph0112201
D. Bastieri: Flux extrapolation – GLAST s/w meeting – Udine, Jan. 31st 2003.
6
EGRET – Observation time: ΔTσ=5
List of EGRET sources. Observation time to reach σ = 5 level for
In the histogram on the
EGRET sources. X-bins are logarithmic.
left are shown the
ΔTσ=5 for each source
observable by MAGIC.
There are 46 sources
with an expected ΔTσ=5
25
13
8
less than 100 hours.
D. Bastieri: Flux extrapolation – GLAST s/w meeting – Udine, Jan. 31st 2003.
5
3
7
Catalogue of the best TeV candidates
Ensemble of 246 different
objects

33 TeV Candidates
Selection criterium
based on RADIO fluxes
for optical fluxes
possible contamination
from the host galaxy.
D. Bastieri: Flux extrapolation – GLAST s/w meeting – Udine, Jan. 31st 2003.
8
Costamante & Ghisellini: new lists
Costamante-Ghisellini
criterium
33 sources
 23 with data on z
and with a total
obs. time  0
Ghisellini model:
Theoretical approach.
SSC-model + fit on
LC, Lsyn ratio.
Data on
A, α, z,
RA and dec.
Fossati model:
Phenomenology.
SSC-model + LC ~ Lsyn
D. Bastieri: Flux extrapolation – GLAST s/w meeting – Udine, Jan. 31st 2003.
Tables
9
Costamante: Ghisellini model
Source
2200+428
1553+113
1114+202
1136+673
1417+257
1218+304
1101-232
0414+009
1133+704
1959+650
0556-384
0120+340
1727+502
0323+022
2356-309
1011+496
1741+196
0229+200
1722+119
0033+595
1440+122
0214+517
0548-322
z
0.069
0.360
0.139
0.135
0.237
0.182
0.186
0.287
0.045
0.047
0.034
0.272
0.055
0.147
0.165
0.200
0.084
0.139
0.018
0.086
0.162
0.049
0.069

3.74
2.97
3.21
2.98
2.73
2.78
2.19
2.93
3.12
3.10
2.28
2.39
2.80
3.37
2.42
2.57
2.34
2.25
3.11
2.22
2.51
2.55
2.36
A
F (Hz)
–5
1.06×10
16.
–7
3.21×10
2.9
–7
2.91×10
1.6
–8
8.02×10
0.82
4.09×10–8
0.68
–8
4.19×10
0.62
–9
8.18×10
0.52
–8
4.23×10
0.44
5.36×10–8
0.42
–8
4.88×10
0.38
–9
6.13×10
0.32
–9
8.15×10
0.29
–8
2.03×10
0.28
7.33×10–8
0.28
–9
6.14×10
0.25
–8
1.08×10
0.25
–9
6.03×10
0.24
3.76×10–9
0.18
–8
2.58×10
0.17
–9
2.65×10
0.14
–9
4.98×10
0.13
4.84×10–9
0.12
–9
2.39×10
0.12
Ts>5
3.5 s
1.8 min
6.4 min
23 min
34 min
40 min
57 min
1.3 hr
1.5 hr
1.8 hr
2.6 hr
3 hr
3.2 hr
3.4 hr
4.1 hr
4.1 hr
4.3 hr
7.5 hr
8.7 hr
13 hr
15 hr
18 hr
19 hr
7 sources
12 sources
4 sources
D. Bastieri: Flux extrapolation – GLAST s/w meeting – Udine, Jan. 31st 2003.
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Costamante: Fossati model
Source
2200+428
1133+704
1722+119
1959+650
0214+517
0548-322
1727+502
0556-384
1741+196
1553+113
0033+595
1114+202
2356-309
1101-232
0229+200
1136+673
1218+304
0323+022
1440+122
1417+257
0120+340
0414+009
1011+496
z
0.069
0.045
0.018
0.047
0.049
0.069
0.055
0.034
0.084
0.360
0.086
0.139
0.165
0.186
0.139
0.135
0.182
0.147
0.162
0.237
0.272
0.287
0.200

2.50
1.99
1.89
2.01
1.99
2.01
2.00
1.93
2.08
2.88
1.99
2.07
2.10
2.14
2.03
2.03
2.12
2.03
2.02
2.14
2.20
2.26
2.31
A
F (Hz)
–7
1.69×10
4.6
2.44×10–8
2.3
–8
2.03×10
2.2
–8
2.32×10
2.
–8
1.66×10
1.4
–8
1.34×10
1.4
1.53×10–8
1.3
–8
1.15×10
1.2
–8
1.69×10
1.2
–8
9.33×10
1.
5.79×10–9
0.52
–9
5.23×10
0.39
–9
4.35×10
0.35
–9
4.48×10
0.32
3.44×10–9
0.28
–9
3.24×10
0.27
–9
3.92×10
0.26
–9
2.94×10
0.23
–9
2.65×10
0.21
2.50×10–9
0.16
–9
2.69×10
0.15
–9
3.03×10
0.14
–9
2.07×10
0.086
Ts>5
43 s
2.9 min
3.1 min
3.8 min
7.3 min
8.3 min
8.8 min
9.8 min
10 min
14 min
57 min
1.7 hr
2.1 hr
2.6 hr
3.3 hr
3.6 hr
3.7 hr
4.8 hr
5.6 hr
10 hr
11 hr
13 hr
35 hr
11 sources
9 sources
3 sources
D. Bastieri: Flux extrapolation – GLAST s/w meeting – Udine, Jan. 31st 2003.
11
Conclusions ???
46 + 23 Blazars are observable with σ ~ 5 in ~ 1 hour.
Observation of “near”-FSRQs can provide a tool to measure
internal cutoff and to verify emission models.
dI/dE =
A×E–
different
emission models
“virtualAGN”
engine
D. Bastieri: Flux extrapolation – GLAST s/w meeting – Udine, Jan. 31st 2003.
12