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FARADAY CONVERSIONIn Turbulent Blazar Jets
Nicholas MacDonaldBoston University
Polarised Emission from Astrophysical JetsJune 13th 2017
Talk Outline
A brief introduction to Faraday Conversion
Can a turbulent multi-zone blazar emission model produce circularly polarized radiation?
What do changes in the sign of circular polarization tell us about conditions in the jet?
How sensitive is circular polarization to the plasma composition of the jet?
Future Work: Particle-in-Cell Jet Simulations
Polarised Emission from Astrophysical JetsJune 13th 2017
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3
A brief introduction to Faraday Conversion
nrao.edu
The Very Long Baseline Array
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nrao.edu
5
6 http://www.physics.purdue.edu/MOJAVE/
6 http://www.physics.purdue.edu/MOJAVE/
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7
Recollimation Shock
Homan et al. (2009)
3C 279
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Homan et al. (2009)
3C 279
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Circular Polarization
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9
Turbulence
Marscher (2014)
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The Turbulent Extreme Multi-Zone (TEMZ) Model
Marscher (2014)
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The Turbulent Extreme Multi-Zone (TEMZ) Model
?
Solving the Full Stokes Equations of Polarized Radiative Transfer
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����������������
�d
dl+ κI
�κQ κU κV
κQ
�d
dl+ κI
�κ∗
V −κ∗U
κU −κ∗V
�d
dl+ κI
�κ∗
Q
κV κ∗U −κ∗
Q
�d
dl+ κI
�
����������������
����������������
Iν
Qν
Uν
Vν
����������������
=
����������������
η Iν
η Qν
η Uν
η Vν
����������������
13
Jones & O’Dell (1977)
����������������
�d
dl+ κI
�κQ κU κV
κQ
�d
dl+ κI
�κ∗
V −κ∗U
κU −κ∗V
�d
dl+ κI
�κ∗
Q
κV κ∗U −κ∗
Q
�d
dl+ κI
�
����������������
����������������
Iν
Qν
Uν
Vν
����������������
=
����������������
η Iν
η Qν
η Uν
η Vν
����������������
13
Jones & O’Dell (1977)
Faraday Rotation
Linear
Linear
Linear
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Faraday Conversion
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Marscher (2014)
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The Turbulent Extreme Multi-Zone (TEMZ) Model
Marscher (2014)
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The Turbulent Extreme Multi-Zone (TEMZ) Model
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Image Plane
TEMZ Computational Grid
Ray Tracing Algorithm
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Image Plane
TEMZ Computational Grid
Γ
Ray Tracing Algorithm
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Image Plane
TEMZ Computational Grid
LOS
Γ
Ray Tracing Algorithm
The RADMC-3D Code
Dullemond (2015)18
Attila Juhasz
radmc3dPy
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Can a turbulent multi-zone blazar emission model produce circularly polarized radiation?
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TEMZ Model
MacDonald et. al (submitted)
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νobs = 43 GHzνobs = 43 GHz
TEMZ Model
MacDonald et. al (submitted)
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νobs = 43 GHzνobs = 43 GHz
TEMZ Model
MacDonald et. al (submitted)
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νobs = 43 GHzνobs = 43 GHz
TEMZ Model
MacDonald et. al (submitted)
24
νobs = 43 GHzνobs = 43 GHz
TEMZ Model
MacDonald et. al (submitted)
25
νobs = 43 GHzνobs = 43 GHz
TEMZ Model
MacDonald et. al (submitted)
26
νobs = 43 GHzνobs = 43 GHz
TEMZ Model
MacDonald et. al (submitted)
27
νobs = 43 GHzνobs = 43 GHz
TEMZ Model
MacDonald et. al (submitted)
27
νobs = 43 GHzνobs = 43 GHz
TEMZ Model
MacDonald et. al (submitted)
really high!
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νobs = 43 GHzνobs = 43 GHz
TEMZ Model
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What do changes in the sign of circular polarization tell us about conditions in the jet?
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University of Michigan Radio Telescope
31Aller, Aller, & Hughes (2011)
31Aller, Aller, & Hughes (2011)
32EnBlin (2003)
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TEMZ Model (Order)
MacDonald et. al (submitted)
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TEMZ Model (Order)
MacDonald et. al (submitted)
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TEMZ Model (Disorder)
MacDonald et. al (submitted)
36
TEMZ Model (Disorder)
MacDonald et. al (submitted)
37
How sensitive is circular polarization to the plasma composition of the jet?
38
νobs = 43 GHzνobs = 43 GHz
Plasma Compostion Study
MacDonald et. al (submitted)
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νobs = 43 GHzνobs = 43 GHz
Plasma Compostion Study
MacDonald et. al (submitted)
40
Future Work: Particle-in-Cell Jet Simulations
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PIC Model
MacDonald et. al (in prep)Nishikawa (private communication)
42MacDonald et. al (in prep)
PIC Model
ATCA
atnf.csiro.au
asc.rssi.ru
RadioAstron
Questions?
