Relativistic induced Compton scattering in synchrotron self-absorbed sources

Sincell, Mark; Krolik, Julian H.

doi:10.1086/174430

Cited by 22 publications

(27 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For reasonable values of the magnetic field the maximum intrinsic temperature that the plasma can have, if it is in dynamic equilibrium, is T o ∼ 10 12 K, because at a higher temperature second order scattering becomes important and rapidly quenchs the plasma (Kellermann & Pauliny-Toth 1969). Somewhat similar arguments have been made by Singal (1986) and by Sincell & Krolik (1994) who derive 3×10 11 K and 2×10…”

Section: Interferometric Brightness Temperaturesupporting

confidence: 60%

Relativistic phenomena in active galactic nuclei

Cohen

Lister

Vermeulen

2005

EAS Publications Series

View full text Add to dashboard Cite

Abstract. The idea that the radio jets in AGN contain material in relativistic motion is supported by many lines of observational evidence, including morphology, brightness temperature estimated with interferometers and with intrinsic variations, interstellar scintillations, X-rays, and superluminal motion. These are largely independent, and taken together make an irrefutable case for relativistic motion.

show abstract

Section: Interferometric Brightness Temperaturesupporting

confidence: 60%

Relativistic phenomena in active galactic nuclei

Cohen

Lister

Vermeulen

2005

EAS Publications Series

View full text Add to dashboard Cite

show abstract

“…If the magnetic field energy density is approximately in equipartition with the particle energy density, the brightness temperature limit is about an order of magnitude less, as suggested by Readhead (1994), Begelman et al (1994), and Sincell & Krolik (1994). ( These papers suggest limits of about 6 ; 10 10 , 10 11 , and 9 ; 10 10 K, respectively, for our LLAGNs.)…”

Section: Intrinsic Implications: Brightness Temperaturementioning

confidence: 57%

The Size of the Radio‐Emitting Region in Low‐Luminosity Active Galactic Nuclei

Anderson

Ulvestad

2005

ApJ

View full text Add to dashboard Cite

We have used the VLA to study radio variability among a sample of 18 low-luminosity active galactic nuclei ( LLAGNs) on timescales of a few hours to 10 days. The goal was to measure or limit the sizes of the LLAGN radioemitting regions in order to use the size measurements as input to models of the radio emission mechanisms in LLAGNs. We detect variability on typical timescales of a few days at a confidence level of 99% in half the target galaxies. Either variability that is intrinsic to the radio-emitting regions or that is caused by scintillation in the Galactic interstellar medium is consistent with the data. For either interpretation, the brightness temperature of the emission is below the inverse Compton limit for all our LLAGNs and has a mean value of about 10 10 K. The variability measurements plus VLBI upper limits imply that the typical angular size of the LLAGN radio cores at 8.5 GHz is 0.2 mas, plus or minus a factor of 2. The $10 10 K brightness temperature strongly suggests that a population of high-energy nonthermal electrons must be present, in addition to a hypothesized thermal population in an accretion flow, in order to produce the observed radio emission.

show abstract

“…where T is the Thomson cross section (Wilson 1982;de Kool & Begelman 1989;Coppi et al 1993;Sincell & Krolik 1994). In this expression, one power of À comes from the transformation of the observed brightness temperature to the comoving frame, and the other comes from the Lorentz contraction of the radial scale length r (or, equivalently, from the Doppler-shifted scattering rate).…”

Section: Induced Compton and Stimulated Raman Scatteringmentioning

confidence: 99%

Cyclotron Maser Emission from Blazar Jets?

Begelman

Ergun

Rees

2005

ApJ

View full text Add to dashboard Cite

We consider the production of electron cyclotron maser emission by low-density, highly magnetized plasmas in relativistic jets. The population inversion required to drive cyclotron maser instability could occur in localized, transient sites where hydromagnetic instabilities, shocks, and/or turbulence lead to magnetic mirroring along current-carrying flux tubes. The maser is pumped as electrons are accelerated by the parallel electric field that develops as a result of the mirror. We estimate the maximum brightness temperatures that can be obtained in a single maser site and in an array of many masers operating simultaneously, under conditions likely to apply in blazar jets. Synchrotron absorption, by relativistic electrons within the jet, presents the largest obstacle to the escape of the maser radiation, and may render most of it invisible. However, we argue that a high brightness temperature could be produced in a thin boundary layer outside the synchrotron photosphere, perhaps in the shear layer along the wall of the jet. Induced Compton scattering provides additional constraints on the maximum brightness temperature of a masing jet. We suggest that recent observations of diffractive scintillation in the blazar J1819+3845, indicating intrinsic brightness temperatures greater than 10^{14} K at 5 GHz, may be explained in terms of cyclotron maser emission. High brightness temperature maser emission from blazar jets may extend to frequencies as high as ~100 GHz, with the maximum possible T_B scaling roughly as 1/frequency. Less massive relativistic jet sources, such as microquasars, are even better candidates for producing cyclotron maser emission, primarily in the infrared and optical bands.Comment: 22 pages, 1 figure, accepted for publication in The Astrophysical Journa

show abstract

Relativistic induced Compton scattering in synchrotron self-absorbed sources

Cited by 22 publications

References 0 publications

Relativistic phenomena in active galactic nuclei

Relativistic phenomena in active galactic nuclei

The Size of the Radio‐Emitting Region in Low‐Luminosity Active Galactic Nuclei

Cyclotron Maser Emission from Blazar Jets?

Contact Info

Product

Resources

About