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The Spectral Energy Distributions and Beaming Effect for Fermi Blazars Junhui Fan Guangzhou University Collaborators: J H Yang, Y Liu, C Lin, Y.H. Yuan, H B Xiao Black Holes and Friends 2 11-13 April 2016, Fudan Univ. China Outline 1.

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The Spectral Energy Distributions and Beaming Effect for Fermi Blazars

Junhui Fan Guangzhou University

Collaborators: J H Yang, Y Liu, C Lin, Y.H.

Yuan, H B Xiao

Black Holes and Friends 2

11-13 April 2016, Fudan Univ. China

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Outline

  • 1. Introduction
  • 2. Spectral Energy Distributions
  • 3. Beaming Effect in Fermi Blazars
  • 4. Summary

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Outline

  • 1. Introduction
  • 2. Spectral Energy Distributions
  • 3. Beaming Effect in Fermi Blazars
  • 4. Summary

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INTRODUCTION

Observations show that some sources with particular observational properties RBLs LBLs 1) BL Lacertae objects--BLs, XBLs HBLs 2) Flat Spectrum Radio Quasars—FSRQs

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AGNs

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What is a BL Lac Object?

BL Lacertae objects. 1) Absence of emission lines in the core sources; weak emission lines were found in BLs (Miller et al. 1978) 2) Rapid and large amplitude variability 3) Nonthermal continuum 4) High and rapidly variable polarization

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What is an FSRQ?

Optically violently variable quasars--OVVs, (m>1.0m) ( Penston & Cannon,1970) Kinman (1975) OVVs

tend to have steep optical spectra and be associated with compact variable radio sources which have flat radio spectra at GHz frequencies.

Highly polarized quasars--HPQs ( p>3.0%), (Moore and Stockman 1981, ApJ, 243 ) , 45% Core-dominated quasars--CDQs ( R = Lc/Le > 1.0) Superluminal Sources--SM β= v/c > 1.0 (Zhang & Fan, 2008, 123 sources)

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INTRODUCTION

BLAZARS (BL Lacs and FSRQs)

extragalactic objects with rapid variability, high luminosity, high and variable polarization, or superluminal motions.

Objects with one of the above properties

BLAZARS

Strong gamma-ray emissions

The term “blazar” was coined, half in jest, by Ed Speigel at the first conference on BL lac objects in Pittsburg, 1978.

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Fan et al. 2013, RAA, Fan et al. 2013, IAUS 290

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INTRODUCTION

BLAZARS (BL Lacs and FSRQs)

Special subclass of AGNs: extragalactic objects with rapid variability, high luminosity, high and variable polarization, have/no strong emission lines, gamma-ray emissions, or superluminal motions. BLAZARS

INTRODUCTION

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AGN Model

Fob=pFin

=(,)

Standard Model for AGNs 活动星系核的标准模型

吸积盘 宽线区 窄线区 喷流 黑洞

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SEDs of Blazars

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Classification of BL Lac Objects

From surveys Radio selected BL Lacertae objects-RBLs, X-ray Selected BL Lacertae objects-XBLs From Spectral Energy Distributions RBLs, energy cutoff frequency at opt/IR XBLs, frequency at UV/X-ray

121 BL Sample (Giommi, Ansari, Micol, Feb, 1995)

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Classification of BL Lac Objects

Padovani & Giommi 1995, ApJ, 444

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Classification of BL Lac Objects

Padovani & Giommi 1996

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Classification of BL Lac Objects

XBL HBL, RBL LBL Padovani & Giommi 1996

RBLs XBLs

LBLs HBLs

LBLs: Low-frequency peaked HBLs: High-frequency peaked

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SED of Blazars Fossati et al. 1998

Compiled 3 subclasses of 126 blazars (RBLs, XBLs, FSRQs)

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Sequence of Blazars

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Giommi et al. 2005, A&A, 434, 385

Detected luminous high frequency BL Lacs low frequency low luminosity BL Lacs Contradict with the “blazar sequence” since there are no lower luminous low frequency or high frequency luminous BL Lacs in Fossati et al. (1998).

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Nieppola et al. 2006, A&A, 445, 441

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Fermi/LAT

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Abdo, et al. 2010, ApJ, 715, 429

set frequency boundary for subclasses of ~ 48 blazars (based on P & G criteria, according to their position in the effective spectral index plot). LSPs: ISPs: HSPs:

Lower, Intermediate, High Synchrotron Peak

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Boundaries for Classifications

LBL Log ν(Hz) IBL Log ν(Hz) HBL Log ν(Hz) Ref < 15 > 15

Padovani & Giommi, 1996

< 14.5 14.5 ~ 16.5 > 16.5 Nieppola et al. 2006 <14 14 ~ 15 > 15 Abdo et al. 2010 Non Consensus

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Outline

  • 1. Introduction
  • 2. Spectral Energy Distributions
  • 3. Beaming Effect in Fermi Blazars
  • 4. Summary

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2.1 SEDs for 1425 Fermi Blazars from 3FGL

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Multi-wavelength data are compiled for 1425 Fermi blazars to calculate the SEDs

Fan et al 2016, in preparation

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2.1 Fitting Results for some sources

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2.2 Distribution of Peak Frequencies

1392

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2.2 Distribution of Peak Frequencies

999 at observer frame

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2.2 Distribution of Peak Frequencies

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999 at source frame

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Bayesian information criterion for model selection, we used 4 components to fit the distribution, but 3 components are enough.

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2.3 Classifications of Fermi Blazars

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14.0 14.0

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Boundaries for Classifications

LBL Log ν(Hz) IBL Log ν(Hz) HBL Log ν(Hz) Ref < 15 > 15 Padovani & Giommi, 1996 < 14.5 14.5 ~ 16.5 > 16.5 Nieppola et al. 2006 <14 14 ~ 15 > 15 Abdo et al. 2010

<14.0 14.0 ~ 15.3 >15.3 This work

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Luminosity-luminosity Correlations

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Luminosity-luminosity Correlations

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Correlation after removing the effect of redshift

Gamma-Radio correlation still exist

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Tramacere-2007 Tramacere-2011

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Outline

  • 1. Introduction
  • 2. Spectral Energy Distributions
  • 3. Beaming Effect in Fermi Blazars
  • 4. Summary

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  • 3. Beaming Effect in Fermi Blazars

3.1 Variability Index 3.2 Doppler factor and viewing angle 3.3 Radio polarization 3.4 Radio and Gamma-Ray Correlation 3.5 Other Correlations and Doppler factor determination 3.6 etc ……

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3.5. Other Correlations and Doppler Factors

  • i. Gamma-Ray luminosity vs. Radio Doppler Factor
  • ii. Gamma-Ray luminosity VS. Superluminal Velocity

iii.Gamma-Ray Luminosity vs. Core-dominance parameter

iv.Gamma-Ray Luminosity vs. peak frequency

  • v. Gamma-Ray Doppler Factors

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3.1 Variability Index vs Peak Frequency

Ackermann et al. 2015

Bastieri, 2016

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3.2 Beaming in LAT Sources

Savolainen et al. 2010, A&A,512

Savolainen et al. considered 62 with apparent velocity from MOJAVE and Doppler factors from radio variability from Metsahovi Radio

  • Observatory. Then compared the source

detected by LAT and those not-detected. They found The FERMI-detected blazars have on average higher Doppler factors than non-FERMI- detected blazars

FERMI

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3.3 Radio Polarization in Fermi Sources

Hovatta et al. 2010, IJMPD

They found that the radio polarization in the FERMI detected era is higher for the investigated sources. In factor, we obtained that the polarization is associated with the Doppler factor (Fan, Cheng, Zhang, 1997, A&A) .

FERMI

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3.3 Polarization & Beaming effect

Fan, Cheng, Zhang, 1997, A&A Fan, 2002, PASJ

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3.4. Radio and Gamma-ray Correlation

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Radio-faint BL Lac objects and their impact

  • n the radio/gamma-ray connection

Giroletti, M, Pavlidou, V., Reimer, A. et al. 2012, AdSpR, 49

FSRQs BL Lacs 8.4GHz

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Gamma-Ray VS. 15 GHz Ackermann,M., Ajello, M., Allafort,A., et al. 2011, ApJ,741

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Gamma-Ray VS. 325 MHz Massaro, et al. 2014, IAUS304

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Gamma-Radio From EGRET

Fan et al. 1998, A&A

EGRET

230GHz

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3.1 to 3.4 suggest Gamma-ray emissions may be strongly beamed.

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3.5. Other Correlations and Doppler Factors

  • i. Gamma-Ray luminosity vs. Radio Doppler Factor
  • ii. Gamma-Ray luminosity VS. Superluminal Velocity

iii.Gamma-Ray Luminosity vs. Core-dominance parameter

iv.Gamma-Ray Luminosity vs. peak frequency

  • v. Gamma-Ray Doppler Factors

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i.

1FGL Catalogue Fan et al. 2010 Ghisellini et al. 1993 Huang, Jiang, Cao, 1999 Lahteenimaki & Valtaoja, 1999 0.8

66 Sources Fan et al. 2013, PASJ

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Pei, Fan, Liu et al. 2016

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169 FDBs 1166 non-FDB

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  • v. Doppler Factor Determination

δ= ？？

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Consideration

The strong γ-rays are detected for so many blazars implying that the beaming effect is presented in the γ -ray emissions, otherwise, the γ-rays should have been absorbed due to pair-production on collision with the lower energetic photons. Mattox, et al(1993). (see also Dondi & Ghisellini,1995; Rani et al. 2012) considered the pair- production optical depth, they assumed that (1) the X-ray is produced in the same region as the γ-rays, and that a similar X-ray intensity was extant at the time of the γ-ray

  • bservation,

(2) the emission region is spherical, (3) the emission is isotropic, and the size of the emission region is constrained by time variation to be less than R = c ΔT/(1+z), there Δ T is the timescale of variability, c is the speed of light, z is the

  • redshift. Finally, they obtained the optical depth,

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Optical Depth

When the beaming is presented in the emission, then the optical depth can be expressed in the following form

δ:Doppler factor FkeV: X-ray flux density α: X-ray spectral index Eγ: γ-ray energy (GeV) ΔT: Variability time scale dL: Luminosity distance (Mpc)

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Doppler Factor

Let the optical depth not be greater than unity, then we have

455 Fermi sources Fan et al. 2014, RAA Time scales

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Gamma & Radio Doppler Factor

BL: 1.5-28.9(264): 6.4+/-3.6 Q: 2.4-99.4 (191), >28, 10Q(5.2%) 9.8+/-5.2(181)

Hovatta et

  • al. 2009

Ghisellini et al. 1993 Fan et al. 2009

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  • 3. Discussions and Summary
  • 1. Fitted SEDs for 1400 Fermi blazars, setting

boundaries for LSPs, ISPs, and HSPs, compared our results with others

  • 2. Investigated beaming effects, determined

Doppler factors for 455 Fermi blazars, and compared with others’ results.

  • 3. Gamma-ray emissions are strongly

beamed

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Thank you for your attention!

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