Insights on Jet Physics & High-Energy Emission Processes from Optical Polarimetry
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Transcript of Insights on Jet Physics & High-Energy Emission Processes from Optical Polarimetry
Insights on Jet Physics & High-Energy Emission Processes
from Optical Polarimetry
Insights on Jet Physics & High-Energy Emission Processes
from Optical PolarimetryEric S. Perlman
Florida Institute of Technology
Collaborators: C. A. Padgett, M. Georganopoulos (UMBC),
F. Dulwich, D. M. Worrall, M. Birkinshaw (Bristol),A. S. Wilson (UMCP), W. B. Sparks, J. A. Biretta
(STScI),C. O’Dea, S. Baum (RIT) + several others…
Eric S. PerlmanFlorida Institute of Technology
Collaborators: C. A. Padgett, M. Georganopoulos (UMBC),
F. Dulwich, D. M. Worrall, M. Birkinshaw (Bristol),A. S. Wilson (UMCP), W. B. Sparks, J. A. Biretta
(STScI),C. O’Dea, S. Baum (RIT) + several others…
Radiation Processes in Jets
Radiation Processes in Jets
Radiation from jets emitted by two processes: synchrotron and inverse-Compton.
For inverse-Compton, the ‘scattered’ photon can be either from within the jet (often called synchrotron self-Compton) or some external source (e.g, the cosmic microwave background or emission line regions).
Important questions:
What does the magnetic field configuration look like?
Does it change as one goes up in energy?
What clues can the magnetic field configuration and ordering give us to radiation and physical mechanisms involved in producing high-energy emissions?
Radiation from jets emitted by two processes: synchrotron and inverse-Compton.
For inverse-Compton, the ‘scattered’ photon can be either from within the jet (often called synchrotron self-Compton) or some external source (e.g, the cosmic microwave background or emission line regions).
Important questions:
What does the magnetic field configuration look like?
Does it change as one goes up in energy?
What clues can the magnetic field configuration and ordering give us to radiation and physical mechanisms involved in producing high-energy emissions?
B
Synchrotron radiation emitted by relativistic particles in magnetic field
e-
Inverse-Compton – scattering interaction between photon and a relativistic particle that results in a higher-energy photon.
Jet “beam”
Perlman et al. 1999
Comparing jet width inRadio, optical, X-rays…
X-ray jet is narrowestOptical jet is nextRadio jet is widest
Perlman & Wilson 2005
Stratified jet…
High energy particles nearer jet axis
Low energy particles evenly distributed
B gets compressed, becomes to jet in shocks inside jet
Shocks accelerate particles, so they brighten optical emission but not radio
Further development of magnetic field depends on two scale lengths:
Magnetic field coherence length lB
Synchrotron cooling length lcool
Stratified jet…
High energy particles nearer jet axis
Low energy particles evenly distributed
B gets compressed, becomes to jet in shocks inside jet
Shocks accelerate particles, so they brighten optical emission but not radio
Further development of magnetic field depends on two scale lengths:
Magnetic field coherence length lB
Synchrotron cooling length lcool
Perlman et al. 1999
lB = lcool Perlman, Georganopoulos & Kazanas, in progress lB=2lcool
3C153C15
Optical and radio jet roughly similar but optical jet narrower
2 knots in X-ray, one coincident with knot C, the other not coincident with radio/opt (A’)
Knot A’ X-ray max corresponds to a feature seen in UV but not in any other r/o band
Optical and radio jet roughly similar but optical jet narrower
2 knots in X-ray, one coincident with knot C, the other not coincident with radio/opt (A’)
Knot A’ X-ray max corresponds to a feature seen in UV but not in any other r/o band
3C 153C 15 Polarimetry differences
more subtle than M87 In all X-ray maxima,
there are interesting radio-optical polzn differences in the neighborhood Resolution marginal
Optical spectrum hardens too
But still indicate stratification 2-component plasma,
relativistic spine, slower sheath
Knot C is a torsional compression of the jet where X-ray emission is triggered
Polarimetry differences more subtle than M87
In all X-ray maxima, there are interesting radio-optical polzn differences in the neighborhood Resolution marginal
Optical spectrum hardens too
But still indicate stratification 2-component plasma,
relativistic spine, slower sheath
Knot C is a torsional compression of the jet where X-ray emission is triggered
3C 2643C 264
Wide-angle tail type source.
Bend about 4” from nucleus
Optical emission dims markedly after 1”
X-ray emission both from inner jet as well as optically fainter outer jet
Wide-angle tail type source.
Bend about 4” from nucleus
Optical emission dims markedly after 1”
X-ray emission both from inner jet as well as optically fainter outer jet
3C 2643C 264
Resolution of Chandra data too low to firmly associate inner jet X-ray emission with optical feature But polarization anomalies at 0.8” from nuclueus, just up-stream of “ring”
Outer jet emission -- optically faint, hard to tell
Resolution of Chandra data too low to firmly associate inner jet X-ray emission with optical feature But polarization anomalies at 0.8” from nuclueus, just up-stream of “ring”
Outer jet emission -- optically faint, hard to tell
3C 3463C 346
Kinked jet seen in both radio and optical
Major bend may be the result of the passage of a companion galaxy
X-ray emission from ~0.3” before kink
Major change in polarization characteristics near kink
Kinked jet seen in both radio and optical
Major bend may be the result of the passage of a companion galaxy
X-ray emission from ~0.3” before kink
Major change in polarization characteristics near kink
3C 3463C 346
Increase in polarization near X-ray maximum.
Small rotation in position angles, only in optical, at that point.
Hardening of optical spectrum at X-ray max.
Synchrotron X-ray emission with associated compression?
Increase in polarization near X-ray maximum.
Small rotation in position angles, only in optical, at that point.
Hardening of optical spectrum at X-ray max.
Synchrotron X-ray emission with associated compression?
3C 3713C 371
3C 3713C 371
Optical shows low polarization in 2 X-ray maxima, high polarization in one.
Significant rotations seen in optical alsoNeither is seen in radio
Optical shows low polarization in 2 X-ray maxima, high polarization in one.
Significant rotations seen in optical alsoNeither is seen in radio
SummarySummary
In all cases, *something* happens in polarimetry at loci of X-ray emission
What happens appears different in each jet and each component
Usually associated with an increase in radio-optical polarimetry differences
Optical spectrum seems to harden at X-ray flux max
X-ray emission from only a small part of jet “cross-section”
Optical Polarimetry can serve as a diagnostic for X-ray emission mechanism
This is crying out to be done for higher-power jets!
In all cases, *something* happens in polarimetry at loci of X-ray emission
What happens appears different in each jet and each component
Usually associated with an increase in radio-optical polarimetry differences
Optical spectrum seems to harden at X-ray flux max
X-ray emission from only a small part of jet “cross-section”
Optical Polarimetry can serve as a diagnostic for X-ray emission mechanism
This is crying out to be done for higher-power jets!