Pagan Ii: The Evolution of Agn Jets on Sub-Parsec Scales

Oh, Junghwan; Trippe, Sascha; Kang, Sincheol; Park, Jong Ho; Lee, Taeseok; Kim, Daewon; Kino, Motoki; Lee, Sang-Sung; Sohn, Bong Won

doi:10.5303/jkas.2015.48.5.299

Cited by 12 publications

(7 citation statements)

References 45 publications

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“…They equally state a possible range of θ ∼ 10-25 • for a number of observed knots with a weighted average of 18.1 • . This range is consistent with an upper limit of 20 • found by Oh et al (2015). We adopt the lower limit of 10 • estimated by Lewis et al (2005) for the large-scale morphology, although lower values cannot be excluded based on parsec-scale kinematics.…”

Section: Appendix A: Constraints On the Viewing Angle And The Intrins...supporting

confidence: 86%

VLBA polarimetric monitoring of 3C 111

Kadler

Perucho

Großberger

et al. 2018

A&A

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Context. While studies of large samples of jets of Active Galactic Nuclei (AGN) are important in order to establish a global picture, dedicated single-source studies are an invaluable tool for probing crucial processes within jets on parsec scales. These processes involve in particular the formation and geometry of the jet magnetic field as well as the flow itself. Aims. We aim to better understand the dynamics within relativistic magneto-hydrodynamical flows in the extreme environment and close vicinity of supermassive black holes. Methods. In order to follow that aim, we analyze the peculiar radio galaxy 3C 111, for which long-term polarimetric observations are available. We make use of the high spatial resolution of the VLBA network and the MOJAVE monitoring program, which provides high data quality also for single sources and allows us to study jet dynamics on parsec scales in full polarization with an evenly sampled time-domain. While electric vectors can probe the underlying magnetic field, other properties of the jet such as the variable (polarized) flux density, feature size and brightness temperature, can give valuable insights into the flow itself. We complement the VLBA data with data from the IRAM 30-m Telescope as well as the SMA. Results. We observe a complex evolution of the polarized jet. The electric vector position angles (EVPAs) of features traveling down the jet perform a large rotation of 180 • across a distance of about 20 pc. As opposed to this smooth swing, the EVPAs are strongly variable within the first parsecs of the jet. We find an overall tendency towards transverse EVPAs across the jet with a local anomaly of aligned vectors in between. The polarized flux density increases rapidly at that distance and eventually saturates towards the outermost observable regions. The transverse extent of the flow suddenly decreases coincident with a jump in brightness temperature around where we observe the EVPAs to turn into alignment with the jet flow. Also the gradients of the feature size with distance and the particle density steepen significantly at that region. Conclusions. We interpret the propagating polarized features with shocks and the observed local anomalies with the interaction of these shocks with a localized recollimation shock of the underlying flow. Together with a sheared magnetic field, this shock-shock interaction can explain the large rotation of the EVPA. The superimposed variability of the EVPAs close to the core is likely related to a clumpy Faraday screen, which also contributes significantly to the observed EVPA rotation in that region.

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Section: Appendix A: Constraints On the Viewing Angle And The Intrins...supporting

confidence: 86%

VLBA polarimetric monitoring of 3C 111

Kadler

Perucho

Großberger

et al. 2018

A&A

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“…Additional HST and Chandra observations are required to better constrain the near-IR spectral index and elaborate on these issues. Oh et al (2015) more recently used VLBI observations to constrain the viewing angle of 3C 111 on mas scales to θ 20 degrees and the intrinsic velocity to β 0.98, in agreement with the findings of Jorstad et al (2005). Given the large assumptions and the probable complex structure and dynamics of the hotspot regions, this analysis serves to place an upper limit on the amount of beaming in the jet.…”

Section: Jet Decelerationsupporting

confidence: 58%

The Spectacular Radio-Near-Ir-X-Ray Jet of 3c 111: The X-Ray Emission Mechanism and Jet Kinematics

Clautice

Perlman

Georganopoulos

et al. 2016

ApJ

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Relativistic jets are the most energetic manifestation of the active galactic nucleus (AGN) phenomenon. AGN jets are observed from the radio through gamma-rays and carry copious amounts of matter and energy from the sub-parsec central regions out to the kiloparsec and often megaparsec scale galaxy and cluster environs. While most spatially resolved jets are seen in the radio, an increasing number have been discovered to emit in the optical/near-IR and/or X-ray bands. Here we discuss a spectacular example of this class, the 3C 111 jet, housed in one of the nearest, double-lobed FR II radio galaxies known. We discuss new, deep Chandra and HST observations that reveal both near-IR and X-ray emission from several components of the 3C 111 jet, as well as both the northern and southern hotspots. Important differences are seen between the morphologies in the radio, X-ray, and near-IR bands. The long (over 100 kpc on each side), straight nature of this jet makes it an excellent prototype for future, deep observations, as it is one of the longest such features seen in the radio, near-IR/optical and X-ray bands. Several independent lines of evidence, including the X-ray and broadband spectral shape as well as the implied velocity of the approaching hotspot, lead us to strongly disfavor the EC/CMB model and instead favor a two-component synchrotron model to explain the observed X-ray emission for several jet components. Future observations with NuSTAR, HST, and Chandra will allow us to further constrain the emission mechanisms.

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“…The significant difference in the jet kinematic results of different studies could originate from the low cadence ( 1 year) in the previous observations and the re-brightened regions possibly existing in the jet of NGC 315. Motivated by these controversial results, we have performed dense monitoring observations with the KVN and VERA array (KaVA, Niinuma et al 2014;Oh et al 2015;Wajima et al 2016;Asada et al 2017;Cho et al 2017;Hada et al 2017;An et al 2018;Lee et al 2019;Zhao et al 2019). We present the details of our observations, data reduction, kinematic analysis and results in Appendix C.…”

Section: Jet Velocity Fieldmentioning

confidence: 99%

Jet Collimation and Acceleration in the Giant Radio Galaxy NGC 315

Park

Hada

Nakamura

et al. 2021

ApJ

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We study the collimation and acceleration of jets in the nearby giant radio galaxy NGC 315, using multifrequency Very Long Baseline Array observations and archival High Sensitivity Array and Very Large Array data. We find that the jet geometry transitions from a semi-parabolic shape into a conical/hyperbolic shape at a distance of ≈105 gravitational radii. We constrain the frequency-dependent position of the core, from which we locate the jet base. The jet collimation profile in the parabolic region is in good agreement with the steady axisymmetric force-free electrodynamic solution for the outermost poloidal magnetic field line anchored to the black hole event horizon on the equatorial plane, similar to the nearby radio galaxies M87 and NGC 6251. The velocity field derived from the asymmetry in brightness between the jet and counterjet shows gradual acceleration up to the bulk Lorentz factor of Γ ∼ 3 in the region where the jet collimation occurs, confirming the presence of the jet acceleration and collimation zone. These results suggest that the jets are collimated by the pressure of the surrounding medium and accelerated by converting Poynting flux to kinetic energy flux. We discover limb brightening of the jet in a limited distance range where the angular resolution of our data is sufficient to resolve the jet transverse structure. This indicates that either the jet has a stratified velocity field of fast-inner and slow-outer layers or the particle acceleration process is more efficient in the outer layer owing to the interaction with the surroundings on parsec scales.

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Pagan Ii: The Evolution of Agn Jets on Sub-Parsec Scales

Cited by 12 publications

References 45 publications

VLBA polarimetric monitoring of 3C 111

VLBA polarimetric monitoring of 3C 111

The Spectacular Radio-Near-Ir-X-Ray Jet of 3c 111: The X-Ray Emission Mechanism and Jet Kinematics

Jet Collimation and Acceleration in the Giant Radio Galaxy NGC 315

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