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!