Astrophysical Radiation Mechanisms and Polarization. Markus Böttcher North-West University Potchefstroom, South Africa
|
|
- Merry Gilmore
- 5 years ago
- Views:
Transcription
1 Astrophysical Radiation Mechanisms and Polarization Markus Böttcher North-West University Potchefstroom, South Africa
2 Outline 1. Introduction to Radiation Transfer 2. Blackbody Spectrum Brightness Temperature 3. Introduction to Synchrotron Radiation (spectra, energy losses, polarization, Stokes parameters) 4. Introduction to Compton Scattering (spectra, energy losses, Compton polarization, X-ray/γ-ray polarimetry)
3 Radiation Transfer z I ν II νν = dddd dddd ccccccθθ dddd dddd ddω dω θ dθ dφ da y x
4 Radiation Transfer Emission j ν I ν 0 dddd νν dddd = jj νν em dddd νν dddd = jj νν κκκκ II νν Optical depth τ ν : dτ ν = κ ν ds => Absorption κ ν dddd νν dddd = κκ νν II νν abs dddd νν ddττ νν = SS νν II νν Source Function: SS νν = jj νν κκ νν Radiative Transfer Equation General solution for homogeneous S ν : I ν (τ ν ) = I ν (0) e -τ ν + S ν (1 e -τ ν)
5 Radiation Transfer (II) Special Cases I + S ν (1 e -τ ν (τ ν ) = I ν (0) e -τ ν ν) 1) Absorption spectra Bright background source behind a cold absorber (S ν 0)
6 Radiation Transfer (III) Special Cases I I ν (0) e -τ ν + S ν (1 e -τ ν (τ ν ) = ν) S ν 2) Emission spectra No significant background source (I ν (0) 0) I) Optically thick emission: (τ ν >> 1)
7 Radiation Transfer (IV) Special Cases I = I ν (0) e -τ ν + (1 e -τ ν (τ ν ) S ν τ ν j ν ν) s 2) Emission spectra No significant background source (I λ (0) 0) II) Optically thin emission: (τ λ << 1)
8 Outline 1. Introduction to Radiation Transfer 2. Blackbody Spectrum Brightness Temperature 3. Introduction to Synchrotron Radiation (spectra, energy losses, polarization, Stokes parameters) 4. Introduction to Compton Scattering (spectra, energy losses, Compton polarization, X-ray/γ-ray polarimetry)
9 Thermal Blackbody Radiation I ν (τ ν ) = I ν (0) e -τ ν + S ν (1 e -τ ν) In Thermal Equilibrium (LTE): S ν = I ν = B ν (T) = 2 h νν3 cc 2 1 (ee hνν /kk BB TT 1) = Planck Function Rayleigh-Jeans Limit: hν << k B T => B ν (T) 2 νν2 cc 2 kk BB TT
10 Thermal Blackbody Spectrum
11 Brightness Temperature Define Brightness Temperature T b by setting measured intensity I ν equal to Blackbody in Rayleigh-Jeans Limit: I ν = 2 (ν 2 /c 2 ) k B T b T b = II νν cc2 2 νν 2 kk BB Note: T b usually has nothing to do with the source s real temperature!
12 Brightness Temperature Brightness temperatures T b > K seem unphysical because of strong Compton scattering (see point 4 below) but many active galactic nuclei show T b > K (Angelakis et al. 2012)
13 Relativistic Beaming / Boosting In the co-moving frame of the emission region: In the stationary (observer s) frame: δ = (Γ[1 β Γ cosθ]) -1 : Doppler boosting factor ν Γ = (1 β Γ2 ) 1/2 Isotropic emission I ν at frequency ν Time interval t var Beamed emission: I ν = δ 3 I ν ν = δ ν For power-law F ν ν α : F ν = δ (3+α) F ν Time interval t var = t var / δ
14 Relativistic Beaming / Boosting F ν νf ν δ δ 3 ν α δ 3+α δ δ 4 νf ν pk L 4π d 2 L ν ν L ~ δ 4 L T b ~ δ 3 T b (if the size of the emitter is determined from variability)
15 Outline 1. Introduction to Radiation Transfer 2. Blackbody Spectrum Brightness Temperature 3. Introduction to Synchrotron Radiation (spectra, energy losses, polarization, Stokes parameters) 4. Introduction to Compton Scattering (spectra, energy losses, Compton polarization, X-ray/γ-ray polarimetry)
16 Cyclotron/Synchrotron Radiation Cyclotron frequency: ν cy = eb/(2πm e c) ~ 2.8*10 6 (B/G) Hz I ν Nonrelativistic electrons Harmonics: Magnetic field B Cyclotron radiation I n ~ (v/c) 2n ν cy ν
17 Synchrotron Radiation Relativistic electrons: ν sy (γ) ~ 4.2*10 6 (B/G) γ 2 Hz Power output into synchrotron radiation (single electron): Log(I ν ) ν 1/3 e ν/ν sy Single Electron ν sy Log(ν)
18 Synchrotron Emissivity
19 Synchrotron Radiation Power-law distribution of relativistic electrons: N e (γ) ~ γ -p If there are electrons with ν = ν sy (γ), then: j ν ~ ν -α κ ν ~ ν -β α = (p 1)/2 β = (p+4)/2 log(i ν ) Opt. thick ν 5/2 Opt. thin ν -(p 1)/2 Log(ν)
20 Polarization Preferred direction of E-field vectors of radiation B. β β n Obs.. E rad ~ n x [(n β) x β] E rad predominantly to projection of B
21 Synchrotron Polarization p = 2 Π = 69 % p = 3 Π = 75 %
22 Stokes Parameters +Q -U y -Q +U χ E rad x (= North) Define Stokes Parameters: χ = polarization angle (180 o ambituity!) Ι = Total intensity -> Polarized Intensity Ι pol = Π Ι Q = Ι pol cos(2β) cos(2χ) (β = phase-shift y vs. x => circ. pol.) U = Ι pol cos(2β) sin(2χ) V = Ι pol sin(2β) = circularly polarized intensity (typically, β << 1)
23 Stokes Parameters Stokes parameters are additive:
24 Outline 1. Introduction to Radiation Transfer 2. Blackbody Spectrum Brightness Temperature 3. Introduction to Synchrotron Radiation (spectra, energy losses, polarization, Stokes parameters) 4. Introduction to Compton Scattering (spectra, energy losses, Compton polarization, X-ray/γ-ray polarimetry)
25 Compton Scattering In the electron rest frame: ε = hν/(m e c 2 ) For ε' << 1 ε' s ε' (elastic scattering Thomson Regime) For ε' >> 1 ε' s ~ 1 (inelastic scattering Klein-Nishina [KN] Regime)
26 Compton Scattering Thomson
27 Compton Scattering by Relativistic Electrons Thomson Regime µ = cos(θ) θ ph in electron rest frame ( ): ε = ε γ (1 βµ) In Thomson Regime (ε << 1): ε s = ε Doppler boost into lab frame: Concentrated in forward direction (Ω e ) ε s = γ ε s = ε γ 2 (1 βµ)
28 Compton Losses and Spectra Power output into Compton radiation (single electron):
29 Compton Spectra Power-law distribution of relativistic electrons: N e (γ) ~ γ -p If there are electrons with ν = ν C (γ), then: j ν ~ ν -α α = (p 1)/2 log(i ν ) ν 2 ν -(p 1)/2 ν = ν 0 γ min 2 Log(ν)
30 Compton Scattering by Relativistic Electrons KN Regime ph in electron rest frame ( ): In the KN-Regime (ε >> 1): ε s = 1 Doppler boost into lab frame: ε = ε γ (1 βµ) ε s = γ ε s = γ Photon takes all of the electron s energy (ε s ~ εγ 2 > γ would violate energy conservation!) F ν Cut-off in the resulting Comptonscattered spectra around ε s ~ 1/ε ε 1 1/ε ε 2 ε s
31 Total Energy Loss Rate of Relativistic Electrons dγ/dt Thomson Klein-Nishina 1/ε γ Compton energy loss becomes less efficient at high energies (Klein-Nishina regime).
32 Compton Polarization Compton cross section is polarization-dependent: (e - rest frame) ε = hν/(m e c 2 ) Thomson regime: ε ε dσ/dω = 0 if e e = 0 Scattering preferentially in the plane perpendicular to e! Preferred EVPA is preserved. p p e k Scattering of polarized rad. by relativistic e - => Π reduced to ~ ½ of target-photon polarization.
33 X-ray Polarimeters INTEGRAL XIPE X-Calibur PolSTAR ASTROSAT
34 X-Ray Polarimeters B Single Compton scattering Look for angular modulation of scattered X-rays
35 X-Ray Polarimetry (POLAR: Kole et al. 2016)
36 Gamma-Ray Polarimetry with Fermi-LAT e k e - e + e + e - pair is preferentially produced in the plane of (k, e) of the γ-ray. Potentially detectable at E < 200 MeV PANGU / eastrogam
37 Thank you!
38
39
40 Outline 1. Introduction to Radiation Transfer 2. Radiation Mechanisms: Introduction to Synchrotron Radiation (spectra, energy losses, polarization, Stokes parameters) 3. Introduction to Compton Scattering (spectra, energy losses, Compton polarization, X-ray/γ-ray polarimetry) 4. Introduction to γγ absorption / pair production, Doppler factor estimate from γγ opacity
41 γγ Absorption and Pair Production Threshold energy ε thr of a γ-ray to interact with a background photon with energy ε 1 : 2 ε thr = ε 1 (1 cosθ) e + e - θ ε pk ~ 2/ε 1 ε 1 ε γ
42 γγ Absorption Delta-Function Approximation: VHE gamma-rays interact preferentially with IR photons:
43 Spectrum of the Extrgalactic Background Light (EBL) Starlight Dust (Finke et al. 2010)
44 EBL Absorption (Finke et al. 2010)
45 γγ Absorption Intrinsic to the Source Optical depth to γγ-absorption: ττ γγγγ εε γγ ~ nn ppp 2 εε γγ RRRR TT nn ppp ~ LL 4ππ RR 2 cc εε mm ee cc 2 = 4ππ dd LL 2 FF 4ππ RR 2 cc εε mm ee cc 2 Importance of intrinsic γγ-absorption is estimated by the Compactness Parameter:
46 γγ Absorption Intrinsic to the Source Estimate R from variability time scale: RR ~ cc tt vvvvvv Optical depth to γγ-absorption: ττ γγγγ εε γγ ~ dd LL2 FF 2 εε σσ TT εε γγ tt vvvvvv ( 2 ) mm εε ee cc 4 γγ PKS VHE γ-rays (Aharonian et al. 2007) With F x and t var from PKS : τ γγ (ε TeV ) >> 1
47 Relativistic Beaming / Boosting In the co-moving frame of the emission region: In the stationary (observer s) frame: δ = (Γ[1 β Γ cosθ]) -1 : Doppler boosting factor ν Γ = (1 β Γ2 ) 1/2 Isotropic emission I ν at frequency ν Time interval t var Beamed emission: I ν = δ 3 I ν ν = δ ν For power-law F ν ν α : F ν = δ (3+α) F ν Time interval t var = t var / δ
48 Relativistic Beaming / Boosting F ν νf ν δ δ 3 ν α δ 3+α δ δ 4 νf ν pk L 4π d 2 L ν ν L ~ δ 4 L
49 γγ Absorption Intrinsic to the Source Optical depth to γγ-absorption: ττ γγγγ εε γγ ~ dd LL2 FF 2 εε σσ TT εε γγ tt vvvvvv ( 2 ) mm εε ee cc 4 γγ FF εε = δ (3+α) FF εε oooooo εε γγ = εε γγ oooooo /δδ tt vvvvvv = δδ tt vvvvvv oooooo ττ γγγγ δ (5+α)
50
51 Radiation Mechanisms ε ν ~ e -(hν/kt) Bremsstrahlung log(i ν ) Opt. thick ~ ν 2 Opt. thin log(ν)
52 Blazars Class of AGN consisting of BL Lac objects and gamma-ray bright quasars Rapidly (often intra-day) variable Strong gamma-ray sources Radio jets, often with superluminal motion Radio and optical polarization
53 Blazar Spectral Energy Distributions (SEDs) 3C66A Non-thermal spectra with two broad bumps: Low-energy (probably synchrotron): radio-ir-optical(-uv-x-rays) High-energy (X-ray γ-rays)
54 (Abdo et al. 2010) Flux and Polarization Variability Multi-wavelength variability on various time scales (months minutes) Sometimes correlated, sometimes not Observed polarization fractions Π obs <~ 10 % << Π max => Not perfectly ordered magnetic fields! Both degree of polarization and polarization angles vary. Swings in polarization angle sometimes associated with high-energy flares!
55 Open Physics Questions Source of Jet Power (Blandford-Znajek / Blandford/Payne?) Physics of jet launching / collimation / acceleration role / topology of magnetic fields Composition of jets (e - -p or e + -e - plasma?) leptonic or hadronic high-energy emission? Mode of particle acceleration (shocks / shear layers / magnetic reconnection?) - role of magnetic fields Location of the energy dissipation / gamma-ray emission region
56 Blazar Models Relativistic jet outflow with Γ 10 Synchrotron emission Injection, acceleration of ultrarelativistic electrons νf ν ν Q e (γ,t) γ -q Compton emission γ 1 γ 2 Injection over finite length near the base of the jet. Additional contribution from γγ absorption along the jet γ Leptonic Models νf ν Seed photons: ν Synchrotron (SSC), Accr. Disk + BLR (EC)
57 Q e,p (γ,t) Injection, acceleration of ultrarelativistic electrons and protons γ 1 γ -q γ 2 γ Blazar Models Relativistic jet outflow with Γ 10 νf ν Protoninduced radiation mechanisms: ν Proton synchrotron pγ pπ 0 π 0 2γ νf ν Synchrotron emission of primary e - ν Hadronic Models pγ nπ + ; π + µ + ν µ µ + e + ν e ν µ secondary µ-, e-synchrotron Cascades
58 Requirements for lepto-hadronic models To exceed p-γ pion production threshold on interactions with synchrotron (optical) photons: E p > 7x10 16 E -1 ph,ev ev For proton synchrotron emission at multi-gev energies: E p up to ~ ev (=> UHECR) Require Larmor radius r L ~ 3x10 16 E 19 /B G cm a few x cm => B 10 G (Also: to suppress leptonic SSC component below synchrotron) inconsistent with radio-core-shift measurements if emission region is located at ~ pc scales (e.g., Zdziarski & Böttcher 2015). Low radiative efficiency: Requiring jet powers L jet ~ L Edd
59 SED Model Fit Degeneracy (HBL) Red = leptonic Green = lepto-hadronic In many cases, leptonic and hadronic models can produce equally good fits to the SEDs. Possible Diagnostics to distinguish: Variability Neutrinos Polarization
60 Polarization Induced by Anisotropic Compton Scattering Summerlin & Baring (2012) Thermal + Non-Thermal Electron Distributions from Diffusive Shock Acceleration
61 Bulk Compton emission (Comptonization of dust-torus IR by thermal e - in the jet) (Baring et al. 2016)
62 Expected Polarization from Bulk Compton IC by Thermal Electrons ε Γ 2 ε 0 IC by Non- Thermal (Relativistic) Electrons (Garrigoux et al., in prep.)
63 Polarization Induced by Anisotropic Scattering E Obs. (Moran 2007)
64 Calculation of X-Ray and Gamma-Ray Polarization in Leptonic and Hadronic Blazar Models Upper limits on high-energy polarization, assuming perfectly ordered magnetic field perpendicular to the line of sight (Zhang & Böttcher 2013) Synchrotron polarization: Standard Rybicki & Lightman description SSC Polarization: Bonometto & Saggion (1974) for Compton scattering in Thomson regime External-Compton emission (relativistic e - ): Unpolarized: e (γ) 1/γ
65 The Doppler Factor Crisis PKS VHE γ-rays γ γ opacity constraints, assuming isotropic emission in the co-moving frame of the emission region => Γ ~ δ > 50 (Aharonian et al. 2007) VHE γ-ray variability on time scales as short as a few minutes! Strong disagreement with observed superluminal motions!
66 Thank you
Diagnostics of Leptonic vs. Hadronic Emission Models for Blazars Prospects for H.E.S.S.-II and CTA Markus Böttcher North-West University
Diagnostics of Leptonic vs. Hadronic Emission Models for Blazars Prospects for H.E.S.S.-II and CTA Markus Böttcher North-West University Potchefstroom South Africa Q e (g,t) Injection, acceleration of
More informationModels for the Spectral Energy Distributions and Variability of Blazars
Models for the Spectral Energy Distributions and Variability of Blazars Markus Böttcher Ohio University, Athens, OH, USA Fermi Meets Jansky Bonn, Germany, June 21, 2010 Outline: 1) Introduction to leptonic
More informationCan blazar flares be triggered by the VHE gamma-rays from the surrounding of a supermassive black hole?
Can blazar flares be triggered by the VHE gamma-rays from the surrounding of a supermassive black hole? Department of Astrophysics, University of Lodz, Lodz, Poland E-mail: p.banasinski@uni.lodz.pl Wlodek
More informationDiversity of Multi-wavelength Behavior of Relativistic Jet in 3C 279 Discovered During the Fermi Era
Diversity of Multi-wavelength Behavior of Relativistic Jet in 3C 279 Discovered During the Fermi Era Rapid Variability of Blazar 3C 279 during Flaring States in 2013-2014 with Joint Fermi-LAT, NuSTAR,
More informationThe 2006 Giant Flare in PKS and Unidentified TeV Sources. Justin Finke Naval Research Laboratory 5 June 2008
The 2006 Giant Flare in PKS 2155-304 and Unidentified TeV Sources Justin Finke Naval Research Laboratory 5 June 2008 Outline Part I: The SSC Model Part II: The giant flare in PKS 2155-304 Part III: Blazars
More informationConstraints on Extragalactic Background Light from Cherenkov telescopes: status and perspectives for the next 5 years
Constraints on Extragalactic Background Light from Cherenkov telescopes: status and perspectives for the next 5 years Daniel Mazin 1 and Martin Raue 2 1: IFAE, Barcelona 2: MPIK, Heidelberg This research
More informationModelling the Variability of Blazar Jets
Modelling the Variability of Blazar Jets A Selfconsistent SSC Model Matthias Weidinger Institut für Theoretische Physik und Astrophysik, Universität Würzburg GRK Tage: 24. Juli 2009 M. Weidinger (Uni Wü)
More informationUNDERSTANDING POWERFUL JETS AT DIFFERENT SCALES IN THE FERMI ERA. B. THE KPC SCALE: X-RAY EMISSION MECHANISM AND JET SPEED
UNDERSTANDING POWERFUL JETS AT DIFFERENT SCALES IN THE FERMI ERA. A. THE PC SCALE: LOCATING THE Γ-RAY EMISSION SITE B. THE KPC SCALE: X-RAY EMISSION MECHANISM AND JET SPEED Markos Georganopoulos 1,2 Eileen
More informationHard X-ray emission from Novae
Hard X-ray emission from Novae Indrek Vurm (Columbia University) in collaboration with: Brian D. Metzger, Andrei M. Beloborodov (Columbia) Koji Mukai (NASA) Shocks and Particle Acceleration in Novae and
More informationActive Galactic Nuclei
Active Galactic Nuclei Optical spectra, distance, line width Varieties of AGN and unified scheme Variability and lifetime Black hole mass and growth Geometry: disk, BLR, NLR Reverberation mapping Jets
More informationLeptonic Jet Models of Blazars: Broadband Spectra and Spectral Variability
Leptonic Jet Models of Blazars: Broadband Spectra and Spectral Variability arxiv:astro-ph/9909179v1 Sep 1999 Markus Böttcher Space Physics and Astronomy Department Rice University, MS 8 60 S. Main Street
More informationAstrophysical Radiation Processes
PHY3145 Topics in Theoretical Physics Astrophysical Radiation Processes 3: Relativistic effects I Dr. J. Hatchell, Physics 407, J.Hatchell@exeter.ac.uk Course structure 1. Radiation basics. Radiative transfer.
More informationPhotons in the universe. Indian Institute of Technology Ropar
Photons in the universe Photons in the universe Element production on the sun Spectral lines of hydrogen absorption spectrum absorption hydrogen gas Hydrogen emission spectrum Element production on the
More informationMarkus Boettcher Centre for Space Research, North-West University, Potchefstroom, 2520, South Africa
Time-Dependence of VHE γ-ray induced Pair Cascades in AGN Environments Department of Physics and Astronomy, Rice University, Houston, TX 77005, USA Department of Physics and Astronomy, Ohio University,
More informationHigh-z Blazar SEDs Clues to Evolution in the Early Universe. Hongjun An Roger Romani on behalf of the Fermi-LAT Collaboration
High-z Blazar SEDs Clues to Evolution in the Early Universe Hongjun An Roger Romani on behalf of the Fermi-LAT Collaboration Outline Blazars Blazar emission and spectral energy distribution (SED) models
More informationHigh-energy emission from Gamma-Ray Bursts. Frédéric Daigne Institut d Astrophysique de Paris, Université Pierre et Marie Curie
High-energy emission from Gamma-Ray Bursts Frédéric Daigne Institut d Astrophysique de Paris, Université Pierre et Marie Curie HEPRO III High Energy Phenomena in Relativistic Outflows Barcelona, June 27
More informationVHE emission from radio galaxies
VHE emission from radio galaxies Martin Hardcastle The future of gamma-ray astronomy and the CTA Leicester, October 2010 Outline Recap: radio galaxy physics Inverse-Compton emission Locations of high-energy
More informationGAMMA-RAYS FROM MASSIVE BINARIES
GAMMA-RAYS FROM MASSIVE BINARIES W lodek Bednarek Department of Experimental Physics, University of Lódź, Poland 1. Sources of TeV gamma-rays PSR 1259+63/SS2883 - (HESS) LS 5039 - (HESS) LSI 303 +61 o
More informationPolarization Swings Reveal Magnetic Energy Dissipation in Blazars
Polarization Swings Reveal Magnetic Energy Dissipation in Blazars Xuhui Chen Most of this work is done by : Haocheng Zhang (Ohio University & LANL, USA) Other Collaborators: Markus Boettcher (North-West
More informationMagnetic Fields in Blazar Jets
Magnetic Fields in Blazar Jets Bidzina Z. Kapanadze Ilia State University, Tbilisi, Georgia MFPO 2010- Cracow, May 17-21 Blazars are defined as a AGN class with following features: featureless spectra;
More informationParticle Acceleration and Gamma-Ray Emission from Blazars Susumu Inoue (MPIK/ICRR) - electron + proton acceleration mechanism - leptonic + hadronic
Particle Acceleration and Gamma-Ray Emission from Blazars Susumu Inoue (MPIK/ICRR) - electron + proton acceleration mechanism - leptonic + hadronic emission components blazars relativistic jet viewed near-axis
More informationObservations of Active Galactic Nuclei at very high energies with H.E.S.S.
Observations of Active Galactic Nuclei at very high energies with H.E.S.S. Robert Wagner for the H.E.S.S. Collaboration http://www.mpi-hd.mpg.de/hess/ @hesstelescopes 1 H.E.S.S. High Energy Stereoscopic
More informationg and n from TeV blazars
g and n from TeV blazars Matteo Cerruti CNRS, LPNHE, Paris TeVPA 2017, Columbus, OH, USA 08/11/17 1 CAVEAT Extremely biased talk! Towards TeV sources (as in title) Only focused on stationary states, no
More informationX-ray Radiation, Absorption, and Scattering
X-ray Radiation, Absorption, and Scattering What we can learn from data depend on our understanding of various X-ray emission, scattering, and absorption processes. We will discuss some basic processes:
More informationCompton Scattering I. 1 Introduction
1 Introduction Compton Scattering I Compton scattering is the process whereby photons gain or lose energy from collisions with electrons. It is an important source of radiation at high energies, particularly
More information3145 Topics in Theoretical Physics - radiation processes - Dr J Hatchell. Multiwavelength Milky Way
Multiwavelength Milky Way PHY3145 Topics in Theoretical Physics Astrophysical Radiation Processes Dr. J. Hatchell, Physics 406, J.Hatchell@exeter.ac.uk Textbooks Main texts Rybicki & Lightman Radiative
More informationThe Secondary Universe
Secondary photons and neutrinos from distant blazars and the intergalactic magnetic fields UC Berkeley September 11, 2011 The talk will be based on A new interpretation of the gamma-ray observations of
More informationAccretion Disks. 1. Accretion Efficiency. 2. Eddington Luminosity. 3. Bondi-Hoyle Accretion. 4. Temperature profile and spectrum of accretion disk
Accretion Disks Accretion Disks 1. Accretion Efficiency 2. Eddington Luminosity 3. Bondi-Hoyle Accretion 4. Temperature profile and spectrum of accretion disk 5. Spectra of AGN 5.1 Continuum 5.2 Line Emission
More informationHard Electron Spectra and Polariza2on Proper2es of Rela2vis2c Jets
Hard Electron Spectra and Polariza2on Proper2es of Rela2vis2c Jets Lukasz Stawarz ISAS/JAXA (Japan) Outline Radio Galaxies (M 87) FSRQs BL Lacs Large- Scale Quasar Jets X- ray Binaries (Cyg X- 1) Broad-
More informationBlazars as the Astrophysical Counterparts of the IceCube Neutrinos
Blazars as the Astrophysical Counterparts of the IceCube Neutrinos Maria Petropoulou Department of Physics & Astronomy, Purdue University, West Lafayette, USA Einstein Fellows Symposium Harvard-Smithsonian
More information* What are Jets? * How do Jets Shine? * Why do Jets Form? * When were Jets Made?
* What are Jets? * How do Jets Shine? * Why do Jets Form? * When were Jets Made? 1 * Galaxies contain massive black holes which power AGN * Gas accretes through a magnetized disk * Blazars are relativistically
More informationA -ray View on MWL Studies of Blazars. Stefan J. Wagner LSW Heidelberg
A -ray View on MWL Studies of Blazars Stefan J. Wagner LSW Heidelberg MWL studies of Blazars Marscher, ApJ 216, 244, 1977 MWL studies of Blazars Marscher, ApJ 216, 244, 1977 28.0 rays: Top End and Bottom
More informationFlaring Active Galactic Nuclei: the view from Fermi-LAT
Flaring Active Galactic Nuclei: the view from Fermi-LAT INAF-IASF IASF Palermo On behalf of the Fermi-LAT Collaboration and many multi-wavelength collaborators SciNeGHE 2010 1 The EGRET Era AGN dominate
More informationSpatial Profile of the Emission from Pulsar Wind Nebulae with steady-state 1D Modeling
Spatial Profile of the Emission from Pulsar Wind Nebulae with steady-state 1D Modeling Wataru Ishizaki ( Department of Physics, Graduate School of Science, The University of Tokyo ) Abstract The pulsar
More informationRadiative processes in high energy astrophysical plasmas
Radiative processes in high energy astrophysical plasmas École de physique des Houches 23 Février-8 Mars 2013 R. Belmont Why radiation? Why is radiation so important to understand? Light is a tracer of
More informationAstrophysical Radiation Processes
PHY3145 Topics in Theoretical Physics Astrophysical Radiation Processes 5:Synchrotron and Bremsstrahlung spectra Dr. J. Hatchell, Physics 406, J.Hatchell@exeter.ac.uk Course structure 1. Radiation basics.
More informationOrigin of X-rays in blazars
Origin of X-rays in blazars Greg Madejski, Stanford / KIPAC With much of the work presented here done by Amy Furniss, Masaaki Hayashida, Krzysztof Nalewajko, Marek Sikora, Jim Chiang, David Paneque, Mislav
More informationPropagation of very high energy γ-rays inside massive binaries LS 5039 and LSI
Mon. Not. R. Astron. Soc. 368, 579 591 (2006) doi:10.1111/j.1365-2966.2006.10121.x Propagation of very high energy γ-rays inside massive binaries LS 5039 and LSI +61 303 W. Bednarek Department of Experimental
More informationMillimeter-Wave and Optical Polarimetric Behavior of Blazars
Millimeter-Wave and Optical Polarimetric Behavior of Blazars Iván Agudo Instituto de Astrofísica de Andalucía Granada (Spain) with: Clemens Thum José L. Gómez Sol Molina Carolina Casadio Helmut Wiesemeyer
More informationA Theoretical Model to Explain TeV Gamma-ray and X-ray Correlation in Blazars
A Theoretical Model to Explain TeV Gamma-ray and X-ray Correlation in Blazars Nissim Fraija In collaboration with: Magda Gonzalez Instituto de Astronomia - UNAM TAUP 2015, XIV International Conference
More informationPhoton Interactions in Matter
Radiation Dosimetry Attix 7 Photon Interactions in Matter Ho Kyung Kim hokyung@pusan.ac.kr Pusan National University References F. H. Attix, Introduction to Radiological Physics and Radiation Dosimetry,
More informationFermi: Highlights of GeV Gamma-ray Astronomy
Fermi: Highlights of GeV Gamma-ray Astronomy Dave Thompson NASA GSFC On behalf of the Fermi Gamma-ray Space Telescope Large Area Telescope Collaboration Neutrino Oscillation Workshop Otranto, Lecce, Italy
More informationOpacity and Optical Depth
Opacity and Optical Depth Absorption dominated intensity change can be written as di λ = κ λ ρ I λ ds with κ λ the absorption coefficient, or opacity The initial intensity I λ 0 of a light beam will be
More informationCHAPTER 27. Continuum Emission Mechanisms
CHAPTER 27 Continuum Emission Mechanisms Continuum radiation is any radiation that forms a continuous spectrum and is not restricted to a narrow frequency range. In what follows we briefly describe five
More informationEnergy-dependent variability in blazars SSC simulations
Energy-dependent variability in blazars SSC simulations David Sanchez Laboratoire Leprince-Ringuet, CNRS/IN2P3, Ecole Polytechnique, 91128 Palaiseau, France E-mail: dsanchez@llr.in2p3.fr Berrie Giebels
More informationAnalysis of Five Fermi-LAT LBL/IBL BL Lac Objects: Examining the June 2011 Gamma-ray Flare of BL Lacertae
Analysis of Five Fermi-LAT LBL/IBL BL Lac Objects: Examining the June 2011 Gamma-ray Flare of BL Lacertae Valerie Marchenko 3 August 2012, Nevis Labs, Columbia University https://news.slac.stanford.edu/sites/default/files/images/image/blazar-search-st.jpg
More informationThe Extragalactic Gamma-Ray View of AGILE and Fermi
INAF, Osservatorio Astronomico di Capodimonte 22 February 2012 The Extragalactic Gamma-Ray View of AGILE and Fermi Elena Pian INAF, Trieste Astronomical Observatory & Scuola Normale Superiore di Pisa UNIFIED
More informationGamma-ray flares from 3C454 and PKS 1830 in late 2010: electron energization in the jet is not enough!
Gamma-ray flares from 3C454 and PKS 1830 in late 2010: electron energization in the jet is not enough! Name Affiliation A. Bulgarelli INAF-IASF Bologna A.W. Chen INAF-IASF Milano I. Donnarumma INAF-IASF
More informationActive Galactic Nuclei in the MeV-GeV band (first results from Fermi)
Active Galactic Nuclei in the MeV-GeV band (first results from Fermi) Gino Tosti University & INFN Perugia On behalf of the Fermi-LAT Collaboration 1 Active Galactic Nuclei (AGN) EGRET showed that AGN
More informationShort Course on High Energy Astrophysics. Exploring the Nonthermal Universe with High Energy Gamma Rays
Short Course on High Energy Astrophysics Exploring the Nonthermal Universe with High Energy Gamma Rays Lecture 1: Introduction Felix Aharonian Dublin Institute for Advanced Studies, Dublin Max-Planck Institut
More informationLecture 10: TeV Blazars and EBL
40th Saas-Fee Course: Astrophysics at Very High Energies Lecture 10: TeV Blazars and EBL F.A. Aharonian, DIAS (Dublin) & MPIK (Heidelberg) Les Diablerets, March 15-20, 2010 Blazars - sub-class of AGN dominated
More informationTEMA 6. Continuum Emission
TEMA 6. Continuum Emission AGN Dr. Juan Pablo Torres-Papaqui Departamento de Astronomía Universidad de Guanajuato DA-UG (México) papaqui@astro.ugto.mx División de Ciencias Naturales y Exactas, Campus Guanajuato,
More informationON GRB PHYSICS REVEALED BY FERMI/LAT
Proceedings of the 3rd Galileo Xu Guangqi Meeting International Journal of Modern Physics: Conference Series Vol. 23 (2013) 223 227 c World Scientific Publishing Company DOI: 10.1142/S2010194513011343
More informationCompton Scattering II
Compton Scattering II 1 Introduction In the previous chapter we considered the total power produced by a single electron from inverse Compton scattering. This is useful but limited information. Here we
More informationOn the location and properties of the GeV and TeV emitters of LS 5039
On the location and properties of the GeV and TeV emitters of LS 5039 Víctor Zabalza Max-Planck Institut für Kernphysik, Heidelberg April 17, 2013 Workshop on Variable Galactic Gamma-Ray Sources Víctor
More informationExtreme high-energy variability of Markarian 421
Extreme high-energy variability of Markarian 421 Mrk 421 an extreme blazar Previous observations outstanding science issues 2001 Observations by VERITAS/Whipple 10 m 2001 Light Curve Energy spectrum is
More informationSynchrotron Radiation: II. Spectrum
Synchrotron Radiation: II. Spectrum Massimo Ricotti ricotti@astro.umd.edu University of Maryland Synchrotron Radiation: II. Spectrum p.1/18 ds=v dt_em dt=ds cos(theta)/c=v/c cos(theta)dt_em Synchrotron
More informationLong term multi-wavelength variability studies of the blazar PKS
52nd Rencontres de Moriond 2017 Very High Energy Phenomena in the Universe Long term multi-wavelength variability studies of the blazar PKS 2155-304 Jill Chevalier D. Sanchez, P. Serpico, J-P. Lenain,
More informationBethe-Block. Stopping power of positive muons in copper vs βγ = p/mc. The slight dependence on M at highest energies through T max
Bethe-Block Stopping power of positive muons in copper vs βγ = p/mc. The slight dependence on M at highest energies through T max can be used for PID but typically de/dx depend only on β (given a particle
More informationEBL Studies with the Fermi Gamma-ray Space Telescope
EBL Studies with the Fermi Gamma-ray Space Telescope Luis C. Reyes KICP The Extragalactic Background Light (EBL) What is it? Accumulation of all energy releases in the form of electromagnetic radiation.
More informationChapter 2 Bremsstrahlung and Black Body
Chapter 2 Bremsstrahlung and Black Body 2.1 Bremsstrahlung We will follow an approximate derivation. For a more complete treatment see [2] and [1]. We will consider an electron proton plasma. Definitions:
More informationGamma-rays from black-hole binaries (?)
Gamma-rays from black-hole binaries (?) Valentí Bosch-Ramon Dublin Institute for Advanced Studies Accretion and Outflow in Black Hole Systems IAU Symposium 275: Jets at all Scales Kathmandu, Nepal 13/10/2010
More informationRelativistic jets in AGNs
Mem. S.A.It. Suppl. Vol. 5, 211 c SAIt 2004 Memorie della Supplementi Relativistic jets in AGNs Fabrizio Tavecchio INAF Oss. Astron. di Brera, via Brera 28, 20121 Milano, Italy e-mail: fabrizio@brera.mi.astro.it
More informationActive galactic nuclei (AGN)
Active galactic nuclei (AGN) General characteristics and types Supermassive blackholes (SMBHs) Accretion disks around SMBHs X-ray emission processes Jets and their interaction with ambient medium Radio
More informationConstraining Dark Matter annihilation with the Fermi-LAT isotropic gamma-ray background
Constraining Dark Matter annihilation with the Fermi-LAT isotropic gamma-ray background Fiorenza Donato @ Physics Dept., Un. Torino The gamma-ray sky - Minneapolis, October 10, 2013 Plan of my talk What
More informationRadiative processes from energetic particles II: Gyromagnetic radiation
Hale COLLAGE 2017 Lecture 21 Radiative processes from energetic particles II: Gyromagnetic radiation Bin Chen (New Jersey Institute of Technology) e - Shibata et al. 1995 e - magnetic reconnection Previous
More informationCosmology and fundamental physics with extragalactic TeV γ-rays?
Cosmology and fundamental physics with extragalactic TeV γ-rays? Matthias Lorentz PhD with Pierre Brun at Irfu/SPP DDays 7-8 July 2016 Introduction : my PhD topic What we can learn from TeV photons propagating
More information1. Why photons? 2. Photons in a vacuum
Photons and Other Messengers 1. Why photons? Ask class: most of our information about the universe comes from photons. What are the reasons for this? Let s compare them with other possible messengers,
More informationGamma rays from supernova remnants in clumpy environments.! Stefano Gabici APC, Paris
Gamma rays from supernova remnants in clumpy environments!! Stefano Gabici APC, Paris Overview of the talk Galactic cosmic rays Gamma rays from supernova remnants Hadronic or leptonic? The role of gas
More informationAGILE and multi-wavelength campaigns on blazars!
14 th AGILE Workshop AGILE and multi-wavelength campaigns on blazars S. Vercellone (INAF/IASF Palermo) on behalf of the AGILE AGN WG S. Vercellone INAF/IASF Palermo 14 th AGILE Workshop Rome, June 20-21
More informationAGILE and Blazars: the Unexpected, the Unprecedented, and the Uncut
AGILE and Blazars: the Unexpected, the Unprecedented, and the Uncut Rome, AGILE γ-ray Symposium 2017.12.12 Stefano Vercellone (INAF-OAB) 1 Rationale A review of the whole set of AGILE results on extra-galactic
More informationCosmological Evolution of Blazars
Cosmological Evolution of Blazars Chuck Dermer Naval Research Laboratory The impact of high energy astrophysics experiments on cosmological physics Kavli Institute for Cosmological Physics University of
More informationNEUTRINOS ON ICE THE SEARCH FOR THE COSMIC-RAY SOURCES FE KRAUSS, J. WILMS, M. KADLER, M. KRETER
NEUTRINOS ON ICE THE SEARCH FOR THE COSMIC-RAY SOURCES FE KRAUSS, J. WILMS, M. KADLER, M. KRETER FELICIA.KRAUSS@UVA.NL COSMIC RAYS 2a COSMIC RAYS 1896: Henri Becquerel discovery of radioactivity 1909:
More informationNon-thermal emission from pulsars experimental status and prospects
Non-thermal emission from pulsars experimental status and prospects # γ!"# $%&'() TeV γ-ray astrophysics with VERITAS ( $γ" *$%&'() The charged cosmic radiation - how it all began... Discovery: Victor
More informationarxiv: v1 [astro-ph.he] 5 Mar 2013
Mon. Not. R. Astron. Soc. 000, 1 13 (2012) Printed 7 March 2013 (MN LATEX style file v2.2) and inverse-compton emission from blazar jets - III. Compton-dominant blazars William J. Potter and Garret Cotter
More informationHigh-Energy Plasma Astrophysics and Next Generation Gamma-Ray Observatory Cherenkov Telescope Array
High-Energy Plasma Astrophysics and Next Generation Gamma-Ray Observatory Cherenkov Telescope Array FAPESP CUNY Week, New York, November 2018 M82 Star Formation- Clouds-SNRturbulence connection Sun & Stars
More informationGRB : Modeling of Multiwavelength Data
GRB 090510: Modeling of Multiwavelength Data Soeb Razzaque NRC-NRL, Washington, DC Gamma Ray Bursts Workshop, Nov 8-12, GSFC Detection of GRB 090510 Fermi GBM and LAT observations Trigger on 2009 May 10
More information(X-ray) binaries in γ-rays
(X-ray) binaries in γ-rays Guillaume Dubus thanks to B. Cerutti, S. Corbel, R. Corbet, R. Dubois, G. Henri, A. Hill, M. de Naurois, J. Pétri, A. Szostek..., Fermi/LAT & HESS collaborations TIARA workshop
More informationGlobal evlbi observations of the first gamma-ray RL NLS1
Global evlbi observations of the first gamma-ray RL NLS1 Marcello Giroletti (INAF/IRA), Akihiro Doi (ISAS/JAXA) and Z. Paragi, H. Bignall, L. Foschini, K. Gabanyi, C. Reynolds, and many others Outline
More informationPoS(NEUTEL2017)079. Blazar origin of some IceCube events
Blazar origin of some IceCube events Sarira Sahu Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Circuito Exterior, C.U., A. Postal 70-543, 04510 México DF, México. Astrophysical
More informationQuantum Mechanics. An essential theory to understand properties of matter and light. Chemical Electronic Magnetic Thermal Optical Etc.
Quantum Mechanics An essential theory to understand properties of matter and light. Chemical Electronic Magnetic Thermal Optical Etc. Fall 2018 Prof. Sergio B. Mendes 1 CHAPTER 3 Experimental Basis of
More informationMonitoring of Blazars for variability from MIRO. Kiran S Baliyan Physical Research Laboratory, Ahmedabad, India
Monitoring of Blazars for variability from MIRO Kiran S Baliyan Physical Research Laboratory, Ahmedabad, India Black-holes, Jets and Outflows, Kathmandu, Nepal, October 14, 2013 Enigmatic AGNs AGNs- Huge
More informationRadiation processes and mechanisms in astrophysics I. R Subrahmanyan Notes on ATA lectures at UWA, Perth 18 May 2009
Radiation processes and mechanisms in astrophysics I R Subrahmanyan Notes on ATA lectures at UWA, Perth 18 May 009 Light of the night sky We learn of the universe around us from EM radiation, neutrinos,
More informationGammaray burst spectral evolution in the internal shock model: comparison with the observations
Gammaray burst spectral evolution in the internal shock model: comparison with the observations Ž. Bošnjak, F. Daigne, and G. Dubus Citation: AIP Conference Proceedings 1358, 59 (2011); doi: 10.1063/1.3621737
More informationThe Gamma-ray Sky with ASTROGAM GAMMA-RAY BINARIES. Second Astrogam Workshop Paris, March Josep M. Paredes
The Gamma-ray Sky with ASTROGAM GAMMA-RAY BINARIES Second Astrogam Workshop Paris, 26-27 March 2015 Josep M. Paredes Binary systems with HE and/or VHE gamma-ray emission Microquasars: Accreting XRBs with
More informationHigh energy neutrino signals from NS-NS mergers
High energy neutrino signals from NS-NS mergers He Gao 高鹤 University of Nevada Las Vegas Collaborators: Bing Zhang, Xue-Feng Wu & Zi-Gao Dai 2013-05-08 Multi-Messenger Workshop @ KIAA EM signals for a
More informationHubble Space Telescope ultraviolet spectroscopy of blazars: emission lines properties and black hole masses. E. Pian, R. Falomo, A.
Hubble Space Telescope ultraviolet spectroscopy of blazars: emission lines properties and black hole masses E. Pian, R. Falomo, A. Treves 1 Outline Extra Background Introduction Sample Selection Data Analysis
More informationSet 4: Active Galaxies
Set 4: Active Galaxies Phenomenology History: Seyfert in the 1920;s reported that a small fraction (few tenths of a percent) of galaxies have bright nuclei with broad emission lines. 90% are in spiral
More informationMULTIMESSENGER APPROACH:Using the Different Messengers
MULTIMESSENGER APPROACH:Using the Different Messengers PROTONS p NUCLEI (A,Z) NEUTRINOS νµ PHOTONS LECTURE PLAN: 1) COSMIC RAYS- proton interactions with photons, composition, nuclei interactions with
More informationRadiative processes in GRB (prompt) emission. Asaf Pe er (STScI)
Radiative processes in GRB (prompt) emission Asaf Pe er (STScI) May 2009 Outline Historical approach Synchrotron: pro s and co s Compton scattering in prompt emission (and why it is different than in afterglow)
More information(X-ray) binaries in γ-rays
(X-ray) binaries in γ-rays Guillaume Dubus Understanding relativistic jets, Kraków 2011 Institut de Planétologie et d Astrophysique de Grenoble Variable galactic γ-ray sources gamma-ray binaries O/Be +
More informationBlazars in gamma-ray views
Blazars in gamma-ray views Challenges of AGN jets@naoj, Mitaka 19 January 2017 Masaaki Hayashida M.Hayashida et al. 2015, ApJ, in press (Institute Cosmic-ray research, (arxiv:1502.04699) the Univ. of Tokyo)
More informationMultiwaveband Observations of the TeV Blazar PKS with HESS, Fermi, RXTE and Swift
Multiwaveband Observations of the TeV Blazar PKS 2155-304 with HESS, Fermi, RXTE and Swift David Sanchez on behalf of the Fermi LAT and H.E.S.S. collaborations. LLR 21 janvier 2009 D.Sanchez Multiwaveband
More informationSpecial relativity and light RL 4.1, 4.9, 5.4, (6.7)
Special relativity and light RL 4.1, 4.9, 5.4, (6.7) First: Bremsstrahlung recap Braking radiation, free-free emission Important in hot plasma (e.g. coronae) Most relevant: thermal Bremsstrahlung What
More informationOutline. Today we will learn what is thermal radiation
Thermal Radiation & Outline Today we will learn what is thermal radiation Laws Laws of of themodynamics themodynamics Radiative Radiative Diffusion Diffusion Equation Equation Thermal Thermal Equilibrium
More informationMWL. A Brief Advertisement Before Your Regularly Scheduled Program
MWL A Brief Advertisement Before Your Regularly Scheduled Program PKS 1441+25 PKS 1441+25 z=0.939! VHE detection over more than a single day! PKS 1441+25 37.7% polarization! PKS 1441+25 Continues optical
More informationGamma-ray absorption in the massive TeV Binary LS 5039
Gamma-ray absorption in the massive TeV Binary LS 539 Author: Facultat de Física, Universitat de Barcelona, Diagonal 645, 828 Barcelona, Spain. Advisor: Marc Ribó Abstract: The recent detections of binary
More informationIntroduction to AGN. General Characteristics History Components of AGN The AGN Zoo
Introduction to AGN General Characteristics History Components of AGN The AGN Zoo 1 AGN What are they? Active galactic nucleus compact object in the gravitational center of a galaxy that shows evidence
More informationCorrelation between X-ray and gamma-ray emission in TeV blazars
Correlation between X-ray and gamma-ray emission in TeV blazars Krzysztof Katarzyński Toruń Centre for Astronomy, Nicolaus Copernicus University, Poland Steady Jets and Transient Jets, Bonn 7-8 April 2010
More informationParticle Acceleration by Reconnection and VHE emission Around Black Holes and Relativistic Jets
Particle Acceleration by Reconnection and VHE emission Around Black Holes and Relativistic Jets Deciphering the Violent Universe, Playa del Carmen, December 11-15, 2017 Accretion disk coronae Star Formation
More information