Symbiosis of radio-emitting winds and a jet in a super-Eddington active galactic nucleus

Abstract Super-critical accretion is the most powerful episode in nursing the black hole growth and works in several types of objects. Given that the inverse correlation between radio loudness and Eddington ratio, the super-Eddington active galactic nuclei (AGNs) hold the extremely radio-quiet end of AGNs. Regarding the existence of jet in super-Eddington or radio-quiet AGNs, it’s still unclear. Years of studies indicate nearly all types of super-Eddington accreting systems can launch a jet with one exception: no clear evidence to show jet in super-Eddington AGNs. Observations and theoretical works suggest that super-Eddington accretion can drive high-speed wind-like outflows, therefore produce radio emission through synchrotron (shocked wind) and bremsstrahlung mechanisms. However, such a radio-emitting wind has not been observed in super-Eddington systems except for the Galactic micro-quasar SS 433. In principle, high resolution very long baseline interferometry (VLBI) observation can directly map the inner structure of super-Eddington AGNs. Here, we report the discovery of the coupling of jet and radio-emitting winds in a nearby super-Eddington AGN, I Zw1. Its parsec-scale jet exhibits a wiggling, we interpret this as a jet precession. All the features make IZw1 act as a scaled-up version of SS 433. The observations favour that jet can be launched in extremely radio-quiet AGNs and ubiquitous in super-Eddington accreting systems. The jet wiggling or precession can produce a large aperture-angle shock, which emphasises the jet’s contribution to gas feedback. As the jet precession was also discovered in other super-Eddington systems such as SS 433 and V404 Cygni, it is possible that there is a correlation with each other.

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High-frequency very long baseline interferometry rotation measure of eight active galactic nuclei

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/sts624 ◽

2013 ◽

Vol 429 (4) ◽

pp. 3551-3563 ◽

Cited By ~ 16

Author(s):

J. C. Algaba

Keyword(s):

Active Galactic Nuclei ◽

High Frequency ◽

Very Long Baseline Interferometry ◽

Galactic Nuclei ◽

Long Baseline ◽

Rotation Measure

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Core-shifts and proper-motion constraints in the S5 polar cap sample at the 15 and 43 GHz bands

Astronomy and Astrophysics ◽

10.1051/0004-6361/201731869 ◽

2018 ◽

Vol 614 ◽

pp. A74 ◽

Cited By ~ 3

Author(s):

F. J. Abellán ◽

I. Martí-Vidal ◽

J. M. Marcaide ◽

J. C. Guirado

Keyword(s):

Active Galactic Nuclei ◽

Very Long Baseline Interferometry ◽

Galactic Nuclei ◽

Polar Cap ◽

Motion Constraints ◽

The Core ◽

Long Baseline ◽

Precision Phase ◽

First Time ◽

Core Shift

We have studied a complete radio sample of active galactic nuclei with the very-long-baseline-interferometry (VLBI) technique and for the first time successfully obtained high-precision phase-delay astrometry at Q band (43 GHz) from observations acquired in 2010. We have compared our astrometric results with those obtained with the same technique at U band (15 GHz) from data collected in 2000. The differences in source separations among all the source pairs observed in common at the two epochs are compatible at the 1σ level between U and Q bands. With the benefit of quasi-simultaneous U and Q band observations in 2010, we have studied chromatic effects (core-shift) at the radio source cores with three different methods. The magnitudes of the core-shifts are of the same order (about 0.1 mas) for all methods. However, some discrepancies arise in the orientation of the core-shifts determined through the different methods. In some cases these discrepancies are due to insufficient signal for the method used. In others, the discrepancies reflect assumptions of the methods and could be explained by curvatures in the jets and departures from conical jets.

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The Milliarcsecond Structure of Active Galactic Nuclei Observed with VLBI

Symposium - International Astronomical Union ◽

10.1017/s0074180900141877 ◽

1989 ◽

Vol 134 ◽

pp. 525-528

Author(s):

T. J. Pearson ◽

A. C. S. Readhead

Keyword(s):

Active Galactic Nuclei ◽

Very Long Baseline Interferometry ◽

Galactic Nuclei ◽

Radio Galaxies ◽

Relativistic Motion ◽

Powerful Radio ◽

Long Baseline ◽

Vlbi Observations ◽

Central Engine

Very Long Baseline Interferometry at radio wavelengths is the only technique available for imaging the central few parsecs of powerful radio galaxies and quasars. VLBI observations have shown that in many nuclei radio-emitting material is collimated into a jet on a scale less than a parsec and ejected at relativistic velocities. The interpretation of the observations is complicated by the relativistic motion, however: the images are dominated by those parts of the source that are moving almost directly towards the observer, and thus amplified by relativistic aberration. Nonetheless, the VLBI images are vital for understanding the nature of the central engine, the cause of the collimation, and the physics of the jets.

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Very long baseline interferometry polarization studies of quasars and active galactic nuclei

Canadian Journal of Physics ◽

10.1139/p86-078 ◽

1986 ◽

Vol 64 (4) ◽

pp. 434-439 ◽

Cited By ~ 2

Author(s):

J. F. C. Wardle ◽

D. H. Roberts

Keyword(s):

Active Galactic Nuclei ◽

Linear Polarization ◽

Very Long Baseline Interferometry ◽

Galactic Nuclei ◽

Radio Sources ◽

Long Baseline ◽

First Results ◽

Polarization Studies ◽

Theoretical Issues

We present some first results of a program to map the distribution of linear polarization in compact radio sources with milliarcsecond resolution. We show first-epoch maps of 3C345 and 0735 + 178 and first- and second-epoch maps of OJ287. In general, the polarization is mainly associated with optically thin (jet) components. In the case of OJ287, polarization maps made 1 year apart are strikingly different. We also discuss some of the theoretical issues raised by these observations.

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