Multiband RadioAstron space VLBI imaging of the jet in quasar S5 0836+710

Vega-García, L.; Lobanov, A. P.; Perucho, M.; Bruni, G.; Ros, E.; Anderson, J. M.; Agudo, I.; Davis, R. J.; Gómez, J. L.; Kovalev, Y. Y.; Krichbaum, T. P.; Lisakov, M. M.; Savolainen, Tuomas; Schinzel, F. K.; Zensus, J. A.

doi:10.1051/0004-6361/201935168

Cited by 12 publications

(8 citation statements)

References 63 publications

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“…2.1 (following a standard approach as described in e.g. Vega-García et al 2020). Because the array is large and heterogeneous, the calibration had to be planned with care not to lose any visibility data.…”

Section: Radioastron Observationmentioning

confidence: 99%

Ambilateral collimation study of the twin-jets in NGC 1052

Baczko

Ros

Kadler³

et al. 2022

A&A

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Context. With the increase in the sensitivity and resolution of radio interferometry within recent years, the study of the collimation and acceleration region of extragalactic jets in active galactic nuclei (AGN) has come into focus. Whereas a large fraction of AGN jets show a change from parabolic to conical collimation profile around the Bondi radius, there is a small number of sources that display a deviation from this standard picture, including the radio galaxy NGC 1052. Aims. We study the jet width profile, which provides valuable information about the interplay between the central engine and accretion disk system and the formation, acceleration, and collimation of the jets. Methods. We observed the double-sided, low-radio-power active galaxy NGC 1052 at six frequencies with the VLBA in 2017 and at 22 GHz with RadioAstron in 2016. These data are combined with archival 15, 22, and 43 GHz multi-epoch VLBA observations. From ridge-line fitting we obtained width measurements along the jet and counter-jet which were fitted with single and broken power laws. Results. We find a clear break point in the jet collimation profile at ∼104 RS (Schwarzschild radii). Downstream of the break, the collimation is conical with a power-law index of 1.0 − 1.2 (cylindrical 0; parabolic 0.5; conical 1) for both jets. On the other hand, the upstream power-law index of 0.36 for the approaching jet is neither cylindrical nor parabolic, and the value of 0.16 for the receding jet suggests this latter is close-to cylindrical. For both jets we find a large opening angle of ∼30° at a distance of ∼103 RS and well-collimated structures with an opening angle of < 10° downstream of the break. Conclusions. There are significant differences between the upstream collimation profiles of the approaching (eastern) and receding (western) jets. Absorption or scattering in the surrounding torus as well as an accretion wind may mimic a cylindrical profile. We need to increase the observing frequencies, which do not suffer from absorption, in order to find the true jet collimation profile upstream of 104 RS.

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Section: Radioastron Observationmentioning

confidence: 99%

Ambilateral collimation study of the twin-jets in NGC 1052

Baczko

Ros

Kadler³

et al. 2022

A&A

Self Cite

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“…It is rare to find a single wave pattern of KH instability to characterize the jet oscillation. A superpositon of several oscillatory patterns of KH instability is common in other sources (Vega-García et al 2020). An explanation is that one pattern of KH instability is dominated while other patterns are still growing and do not fully appear, especially considering that the observed region (10 3 ∼ 10 4 R s ) in M 84 is the innermost jet.…”

Section: Jet Oscillationmentioning

confidence: 87%

“…The Mach number in the jet M j and in the ambient medium M x , as well as the the particle density ratio of the jet to the ambient medium η = M 2 j /M 2 x can be calculated with accurate values of the characteristic wavelength, the jet radius, the viewing angle, the jet apparent speed, and the apparent pattern (or wave) speed (Vega-García et al 2020). For the surface and helical mode, the characteristic wavelength is 1.5λ obs .…”

Section: Jet Oscillationmentioning

confidence: 99%

Multi-frequency VLBI Observations of the M 84 Inner Jet/Counterjet

Wang¹,

Wu²,

Shen³

et al. 2022

Preprint

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Observational studies of inner-most regions of the edge-on jets in nearby active galactic nuclei (AGN) are crucial to understand their kinematics and morphology. For the inner jet of the nearby lowluminosity AGN in M 84, we present new high-sensitivity observations with very long baseline interferometry since 2019, as well as archival Very Long Baseline Array observations in 2014. We find that the compact core in M 84 has an inverted-to-flat spectrum from 1.5 to 88 GHz. Based on the turnover frequency of 4.2 ± 0.2 GHz in the spectrum, we estimated a magnetic field strength of 1 ∼ 10 mG and an electron number density of ∼ 10 5 cm −3 in the core region. Three inner jet components within ∼3 mas from the core are identified and traced in the images at 22 GHz, whose apparent speeds are 0.11 c, 0.27 c, and 0.32 c, respectively. We calculate the viewing angle of 58 +17 −18• for the inner jet based on the proper motion and the flux ratio of jet-to-counterjet. A propagating sinusoidal model with a wavelength of ∼3.4 mas is used to fit the helical morphology of the jet extended to 20 mas (∼ 2.2 × 10 4 Schwarzschild Radii).

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“…It is rare to find a single wave pattern of KH instability to characterize the jet oscillation. A superpositon of several oscillatory patterns of KH instability is common in other sources (Vega-García et al 2020). An explanation is that one pattern of KH instability is dominant, while other patterns are still growing and do not fully appear, especially considering that the observed region (10 3 ∼ 10 4 R s ) in M84 is the innermost jet.…”

Section: Jet Oscillationmentioning

confidence: 87%

Multifrequency VLBI Observations of the M84 Inner Jet/Counterjet

Wang

Jiang

Shen

et al. 2022

ApJ

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Observational studies of the innermost regions of the edge-on jets in nearby active galactic nuclei (AGN) are crucial to understanding their kinematics and morphology. For the inner jet of the nearby low-luminosity AGN in M84, we present new high-sensitivity observations with very long baseline Interferometry since 2019, as well as archival Very Long Baseline Array observations in 2014. We find that the compact core in M84 has an inverted-to-flat spectrum from 1.5–88 GHz. Based on the turnover frequency of 4.2 ± 0.2 GHz in the spectrum, we estimated a magnetic field strength of 1 ∼ 10 mG and an electron number density of ∼105 cm−3 in the core region. Three inner jet components within ∼3 mas of the core are identified and traced in the images at 22 GHz, whose apparent speeds are 0.11 c, 0.27 c, and 0.32 c, respectively. We calculate the viewing angle of 58 − 18 + 17 ° for the inner jet based on the proper motion and the flux ratio of jet to counterjet. A propagating sinusoidal model with a wavelength of ∼3.4 mas is used to fit the helical morphology of the jet extended to 20 mas (∼2.2 × 104 Schwarzschild radii).

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Multiband RadioAstron space VLBI imaging of the jet in quasar S5 0836+710

Cited by 12 publications

References 63 publications

Ambilateral collimation study of the twin-jets in NGC 1052

Ambilateral collimation study of the twin-jets in NGC 1052

Multi-frequency VLBI Observations of the M 84 Inner Jet/Counterjet

Multifrequency VLBI Observations of the M84 Inner Jet/Counterjet

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