Blazars: GeV-TeV connection · Location of VHE emission? Difficult inside BLR! Strong absorption...

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Blazars: GeV-TeV connection F.Tavecchio INAF-OAB

Transcript of Blazars: GeV-TeV connection · Location of VHE emission? Difficult inside BLR! Strong absorption...

Page 1: Blazars: GeV-TeV connection · Location of VHE emission? Difficult inside BLR! Strong absorption (E>30 GeV within BLR, E>1 TeV outside) (e.g. Liu et al. 2008, Reimer 2007, FT & Mazin

Blazars: GeV-TeV connection

F.Tavecchio

INAF-OAB

Page 2: Blazars: GeV-TeV connection · Location of VHE emission? Difficult inside BLR! Strong absorption (E>30 GeV within BLR, E>1 TeV outside) (e.g. Liu et al. 2008, Reimer 2007, FT & Mazin

GeV-TeV connection in FSRQs

GeV-TeV connection in extreme HBL

Page 3: Blazars: GeV-TeV connection · Location of VHE emission? Difficult inside BLR! Strong absorption (E>30 GeV within BLR, E>1 TeV outside) (e.g. Liu et al. 2008, Reimer 2007, FT & Mazin

Foss

ati et

al.

1998

; Don

ato

et a

l. 20

01

CT

AGILE

Fermi

The “blazar sequence”

Page 4: Blazars: GeV-TeV connection · Location of VHE emission? Difficult inside BLR! Strong absorption (E>30 GeV within BLR, E>1 TeV outside) (e.g. Liu et al. 2008, Reimer 2007, FT & Mazin

Foss

ati et

al.

1998

; Don

ato

et a

l. 20

01

CT

AGILE

Fermi

The “blazar sequence”

Page 5: Blazars: GeV-TeV connection · Location of VHE emission? Difficult inside BLR! Strong absorption (E>30 GeV within BLR, E>1 TeV outside) (e.g. Liu et al. 2008, Reimer 2007, FT & Mazin

Abdo et al. 2011

Mkn 421Aleksic et al. 2012

Nice description of the HE bump

Page 6: Blazars: GeV-TeV connection · Location of VHE emission? Difficult inside BLR! Strong absorption (E>30 GeV within BLR, E>1 TeV outside) (e.g. Liu et al. 2008, Reimer 2007, FT & Mazin

Abdo et al. 2011

Mkn 421Aleksic et al. 2012

Nice description of the HE bump

Di!erent integration

times!

Page 7: Blazars: GeV-TeV connection · Location of VHE emission? Difficult inside BLR! Strong absorption (E>30 GeV within BLR, E>1 TeV outside) (e.g. Liu et al. 2008, Reimer 2007, FT & Mazin

GeV and TeV emission of FSRQ

Page 8: Blazars: GeV-TeV connection · Location of VHE emission? Difficult inside BLR! Strong absorption (E>30 GeV within BLR, E>1 TeV outside) (e.g. Liu et al. 2008, Reimer 2007, FT & Mazin

e-!

e-

e- !!

B

Dermer et al. 2009Ghisellini, FT 2009Sikora et al. 2009

Accretion disk

BLR

DU

ST

Y T

OR

US

Setting the stage

Page 9: Blazars: GeV-TeV connection · Location of VHE emission? Difficult inside BLR! Strong absorption (E>30 GeV within BLR, E>1 TeV outside) (e.g. Liu et al. 2008, Reimer 2007, FT & Mazin

Bonnoli et al. 2011

Page 10: Blazars: GeV-TeV connection · Location of VHE emission? Difficult inside BLR! Strong absorption (E>30 GeV within BLR, E>1 TeV outside) (e.g. Liu et al. 2008, Reimer 2007, FT & Mazin

Huge optical depth of BLR

FT & Mazin 2009

FT et al. 2012

GeV TeV

Page 11: Blazars: GeV-TeV connection · Location of VHE emission? Difficult inside BLR! Strong absorption (E>30 GeV within BLR, E>1 TeV outside) (e.g. Liu et al. 2008, Reimer 2007, FT & Mazin

The breakthrough: the FSRQ 1222+216

tdouble~10 min!

cm

Page 12: Blazars: GeV-TeV connection · Location of VHE emission? Difficult inside BLR! Strong absorption (E>30 GeV within BLR, E>1 TeV outside) (e.g. Liu et al. 2008, Reimer 2007, FT & Mazin

Location of VHE emission? Difficult inside BLR!

Strong absorption (E>30 GeV within BLR, E>1 TeV outside) (e.g. Liu et al. 2008, Reimer 2007, FT & Mazin 2009)

Decline of the IC scattering efficiency (e.g. Albert et al. 2008, FT & Ghisellini 2008)

General

Model dependent (not applicabile to

hadronic)

Page 13: Blazars: GeV-TeV connection · Location of VHE emission? Difficult inside BLR! Strong absorption (E>30 GeV within BLR, E>1 TeV outside) (e.g. Liu et al. 2008, Reimer 2007, FT & Mazin

RBLR

!

!b

RIR

Tavecchio et al. 2011

External emission?

“Standard” SED

Variable VHE

Page 14: Blazars: GeV-TeV connection · Location of VHE emission? Difficult inside BLR! Strong absorption (E>30 GeV within BLR, E>1 TeV outside) (e.g. Liu et al. 2008, Reimer 2007, FT & Mazin

Tavecchio et al. 2011

Page 15: Blazars: GeV-TeV connection · Location of VHE emission? Difficult inside BLR! Strong absorption (E>30 GeV within BLR, E>1 TeV outside) (e.g. Liu et al. 2008, Reimer 2007, FT & Mazin

e.g. Ghisellini et al. 2008, 2009

Giannios et al 2009

Marscher & Jorstad 2010

Possibilities to reconcile large d and rapid variability

Minijets from fast reconnection

Magnetocentrifugal acceleration

Page 16: Blazars: GeV-TeV connection · Location of VHE emission? Difficult inside BLR! Strong absorption (E>30 GeV within BLR, E>1 TeV outside) (e.g. Liu et al. 2008, Reimer 2007, FT & Mazin

Possibilities to reconcile large d and rapid variability

Minijets from fast reconnection

Magnetocentrifugal acceleration

Too high B? (>100 G, Nalewajko +2012)

E/B~26

Page 17: Blazars: GeV-TeV connection · Location of VHE emission? Difficult inside BLR! Strong absorption (E>30 GeV within BLR, E>1 TeV outside) (e.g. Liu et al. 2008, Reimer 2007, FT & Mazin

Possibilities to reconcile large d and rapid variability

Minijets from fast reconnection

Magnetocentrifugal acceleration

Large IC cooling!

Too high B? (>100 G, Nalewajko +2012)

E/B~26

Page 18: Blazars: GeV-TeV connection · Location of VHE emission? Difficult inside BLR! Strong absorption (E>30 GeV within BLR, E>1 TeV outside) (e.g. Liu et al. 2008, Reimer 2007, FT & Mazin

Possibilities to reconcile large d and rapid variability

Radiative

efficiency

Bromberg & Levinson 2009

"=0.27

2d, semianalitic calculations “Focusing”

Page 19: Blazars: GeV-TeV connection · Location of VHE emission? Difficult inside BLR! Strong absorption (E>30 GeV within BLR, E>1 TeV outside) (e.g. Liu et al. 2008, Reimer 2007, FT & Mazin

RMHD simulations by G. Bodo

Low cool. High Cool.

Page 20: Blazars: GeV-TeV connection · Location of VHE emission? Difficult inside BLR! Strong absorption (E>30 GeV within BLR, E>1 TeV outside) (e.g. Liu et al. 2008, Reimer 2007, FT & Mazin

Dermer et al. 2012

UHE Neutral beams?

neutrinos

Page 21: Blazars: GeV-TeV connection · Location of VHE emission? Difficult inside BLR! Strong absorption (E>30 GeV within BLR, E>1 TeV outside) (e.g. Liu et al. 2008, Reimer 2007, FT & Mazin

An “exotic” scenario: photon-axion oscillation

Tavecchio et al. 2012, submitted

Standard

Axions

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GeV and TeV emission of extreme HBL

Page 23: Blazars: GeV-TeV connection · Location of VHE emission? Difficult inside BLR! Strong absorption (E>30 GeV within BLR, E>1 TeV outside) (e.g. Liu et al. 2008, Reimer 2007, FT & Mazin

FT et al. 2009

Page 24: Blazars: GeV-TeV connection · Location of VHE emission? Difficult inside BLR! Strong absorption (E>30 GeV within BLR, E>1 TeV outside) (e.g. Liu et al. 2008, Reimer 2007, FT & Mazin

B>0

Effective B-field

The reprocessed flux is diluted within a larger

solid angle

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B>0!

FT et al. 2010

Neronov et al. 2010Dolag et al. 2010

Dermer et al. 2011

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Vovk et al. 2012

LAT 3 years!Reprocessed?

Direct?

Page 27: Blazars: GeV-TeV connection · Location of VHE emission? Difficult inside BLR! Strong absorption (E>30 GeV within BLR, E>1 TeV outside) (e.g. Liu et al. 2008, Reimer 2007, FT & Mazin

Bonnoli et al., in prep

A population of IGMF probes?

Page 28: Blazars: GeV-TeV connection · Location of VHE emission? Difficult inside BLR! Strong absorption (E>30 GeV within BLR, E>1 TeV outside) (e.g. Liu et al. 2008, Reimer 2007, FT & Mazin

SUMMARY

LBL-HBL: nice description of IC bump

(caveat: long LAT integration)

FSRQs: unexpected and challenging VHE emission:

need for more examples!

Extreme HBL: probes for EBL and EGMF