Transfer of polarized radiation in self-absorbed synchrotron sources. I - Results for a homogeneous source

Jones, T. W.; O’Dell, Stephen L.

doi:10.1086/155278

Cited by 194 publications

(277 citation statements)

References 0 publications

Supporting

Mentioning

273

Contrasting

Order By: Relevance

“…It has been argued in previous studies (e.g. [9] that intrinsic CP has trouble explaining the highest observed degrees of circular polarization, and in any case, Faraday conversion should generally be much more efficient at generating CP than the synchrotron mechanism under the conditions expected for AGN jets [12]. Overall, it seems likely that the observed CP is predominantly generated by Faraday conversion, and that the observed values of α c are determined by effects associated with the intrinsic inhomogeneity of the jets, as well as the possible presence of several regions of CP of either one or both signs contributing to the observed "core" CP.…”

Section: Pos(ix Evn Symposium)003mentioning

confidence: 89%

“…The two main mechanisms that are usually considered to be the most likely generators of the observed CP are the synchrotron mechanism and the Faraday conversion of linear to circular polarization [13,12,2,21]. Although the intrinsic CP generated by synchrotron radiation may be able to reach a few tenths of a percent at 15 GHz for the magnetic-field strengths characteristic of the observed VLBI cores of AGN (typically ≃ 0.4 G [14,16]), the highest observed m c values seem too high to plausibly be attributed to this mechanism.…”

Section: Introductionmentioning

confidence: 99%

“…Although the intrinsic CP generated by synchrotron radiation may be able to reach a few tenths of a percent at 15 GHz for the magnetic-field strengths characteristic of the observed VLBI cores of AGN (typically ≃ 0.4 G [14,16]), the highest observed m c values seem too high to plausibly be attributed to this mechanism. This suggests that Faraday conversion plays a role, possibly the dominant one, since it is expected to be more efficient at generating CP than the synchrotron mechanism for the conditions in radio cores [12].…”

Section: Introductionmentioning

confidence: 99%

“…Faraday conversion [12,11] occurs because the component of the linear-polarization electric vector parallel to the conversion magnetic field, E , gives rise to oscillations of free charges in the conversion region, while the component orthogonal to this magnetic field, E ⊥ , cannot (the charges are not free to move orthogonal to the magnetic field). This leads to a delay of E relative to E ⊥ , manifest as the introduction of a small amount of circular polarization.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

The 15--43-GHz Parsec-scale Circular Polarization of AGN

Gabuzda¹,

Vitrishchak²

2009

Proceedings of the 9th European VLBI Network Symposium on the Role of VLBI in the Golden Age for Radio Astronomy and EVN Users

View full text Add to dashboard Cite

Vitrishchak et al. [20] have recently published results of parsec-scale circular polarization measurements based on Very Long Baseline Array data for a number of radio-bright, core-dominated Active Galactic Nuclei obtained simultaneously at 15, 22 and 43 GHz. There are very few multifrequency VLBI circular-polarization results to date, making these of considerable interest; we summarize these results here. The degree of circular polarization m c as often rises as falls with increasing frequency between 15 and 22 GHz, while the degree of circular polarisation at 43 GHz is in all cases higher than at 22 and 15 GHz. This is somewhat surprising, since the degree of circular polarization from both synchrotron radiation and Faraday conversion of linear to circular polarization should decrease towards higher frequencies if the source is homogeneous. The increase in m c at 43 GHz may be due to the presence of regions of both positive and negative circular polarisation with different frequency dependences (but decreasing with increasing frequency) on small scales within the core region; alternatively, it may be associated with the intrinsic inhomogeneity of a Blandford-Königl-like jet. There are several cases of changes in sign with frequency, usually between 22 and 43 GHz, and tentative evidence for transverse structure in the circular polarization of 1055+018 and 1334−127 that is consistent with their being generated by either the synchrotron mechanism or Faraday conversion in a helical magnetic field.

show abstract

Section: Pos(ix Evn Symposium)003mentioning

confidence: 89%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

The 15--43-GHz Parsec-scale Circular Polarization of AGN

Gabuzda¹,

Vitrishchak²

2009

Proceedings of the 9th European VLBI Network Symposium on the Role of VLBI in the Golden Age for Radio Astronomy and EVN Users

View full text Add to dashboard Cite

show abstract

“…Ruszkowski and Begelman, 2002 ;Macquart, 2002;Odell, 1977b &1977a), and (ii) vacuum propagation effects due to general relativity, in particular near a rotating black hole (see e.g. Falcke et al, 2000;Agol, 1997;Laor et al, 1990;Connors et al, 1980).…”

Section: Introductionmentioning

confidence: 99%

General Relativistic Magnetoionic Theory

Broderick

Blandford

2003

Astrophysics and Space Science

View full text Add to dashboard Cite

Abstract. We have developed methods for tracing rays and performing radiative transfer through a magnetoactive plasma in a general relativistic environment. The two electromagnetic plasma modes propagate differently due to a combination of dispersive and gravitational effects. We have found that, when given an appropriate environment surrounding the central black hole, it is indeed possible to generate a significant degree of circular polarisation without an appreciable amount of linear polarisation due to these effects alone.

show abstract

Observations and Simulations of Relativistic Jets

Gómez

Relativistic Flows in Astrophysics

View full text Add to dashboard Cite

The recent improvement in VLBI arrays is providing information of the emission and magnetic field structure of relativistic jets, both extragalactic and galactic (microquasars), with unprecedented spatial and temporal resolution. These observations are revealing the importance of the hydrodynamical processes that govern the jet evolution, which can be studied by the recently developed time-dependent relativistic hydrodynamical models. Computation of the non-thermal emission from these hydrodynamical models, and its comparison with actual sources, is proving as one of the most powerful tools in the understanding of the physical processes taking place in these jets. This paper reviews some of the recent observational results, as well as the numerical models used to interpret them.

show abstract

Transfer of polarized radiation in self-absorbed synchrotron sources. I - Results for a homogeneous source

Cited by 194 publications

References 0 publications

The 15--43-GHz Parsec-scale Circular Polarization of AGN

The 15--43-GHz Parsec-scale Circular Polarization of AGN

General Relativistic Magnetoionic Theory

Observations and Simulations of Relativistic Jets

Contact Info

Product

Resources

About