J/MNRAS/495/3576 AGN jet shape transition geometry (Kovalev+, 2020)
A transition from parabolic to conical shape as a common effect in nearby
AGN jets.
Kovalev Y.Y., Pushkarev A.B., Nokhrina E.E., Plavin A.V., Beskin V.S.,
Chernoglazov A.V., Lister M.L., Savolainen T.
<Mon. Not. R. Astron. Soc., 495, 3576-3591 (2020)>
=2020MNRAS.495.3576K 2020MNRAS.495.3576K (SIMBAD/NED BibCode)
ADC_Keywords: Active gal. nuclei ; QSOs ; BL Lac objects ; Radio sources
Keywords: galaxies: active - BL Lacertae objects: general - galaxies: jets -
quasars: general - radio continuum: galaxies
Abstract:
Observational studies of collimation in jets in active galactic nuclei
(AGN) are a key to understanding their formation and acceleration
processes. We have performed an automated search for jet shape
transitions in a sample of 367 AGN using VLBA data at 15 and 1.4GHz.
This search has found 10 out of 29 nearby jets at redshifts z<0.07
with a transition from a parabolic to conical shape, while the full
analysed sample is dominated by distant AGN with a typical z~=1. The
ten AGN are UGC 00773, NGC 1052, 3C 111, 3C 120, TXS 0815-094, Mrk
180, PKS 1514+00, NGC 6251, 3C 371, and BL Lac. We conclude that the
geometry transition may be a common effect in AGN jets. It can be
observed only when sufficient linear resolution is obtained.
Supplementing these results with previously reported shape breaks in
the nearby AGN 1H 0323+342 and M87, we estimate that the break occurs
at 105-106 gravitational radii from the nucleus. We suggest that
the jet shape transition happens when the bulk plasma kinetic energy
flux becomes equal to the Poynting energy flux, while the ambient
medium pressure is assumed to be governed by Bondi accretion. In
general, the break point may not coincide with the Bondi radius. The
observational data support our model predictions on the jet
acceleration and properties of the break point.
Description:
File table3 contains the name of the sources in the B1950 notation,
observing band designations of data used in fit, minimum and maximum
core separations in fit, fitted parameters a, r_0 and power-law index k
and their corresponding errors.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 149 59 Properties for 12 sources with a detected jet
shape break from this study as well as Hada et
al. (2018ApJ...860..141H 2018ApJ...860..141H, 1H 0323+342) and
Asada & Nakamura (2012ApJ...745L..28A 2012ApJ...745L..28A, M87)
table3.dat 58 318 Derived best-fitting parameters of a single fit
dependence d=alpha(r+r0)k for 319 AGN, and
their k-values
refs.dat 85 49 References
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Name Source name (B1950)
9 A1 --- n_Name [*] Note on name (1)
11- 22 A12 --- OName Other name
24 A1 --- Class [QBNG] Optical class (2)
26- 30 F5.3 --- z ?=- Redshift
32- 72 A41 --- r_z Reference for Redshift, in refs.dat file
74- 78 F5.2 c betaapp ?=- Maximum apparent radial speed from
Lister et al. (2019ApJ...874...43L 2019ApJ...874...43L,
Cat. J/ApJ/874/43)
80- 83 F4.1 --- delta ?=- variability Doppler factor from
Hovatta et al. (2009A&A...494..527H 2009A&A...494..527H)
84 A1 --- n_delta [a] Note on delta (3)
86- 89 F4.1 arcmin theta viewing angle
90 A1 --- n_theta [bc] Note on theta (3)
92- 95 F4.2 [Msun] logMBH ?=- Black hole mass estimated basing on
assumption of virialized BLR movement and
correlation between the size of BLR and
ultraviolet (UV)/optical luminosity
97-119 A23 --- r_logMBH Reference for logMBH, in refs.dat file
122-125 F4.2 [Msun] logMBH2 ?=- Black hole mass estimated by a stellar
velocity dispersion method and associated
Fundamental Plane method (for 2200+420)
127-149 A23 --- r_logMBH2 Reference for logMBH2, in refs.dat file
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Note (1): * for data from Hada et al. (2018ApJ...860..141H 2018ApJ...860..141H,, 1H 0323+342) and
Asada & Nakamura (2012ApJ...745L..28A 2012ApJ...745L..28A, M87)
Note (2): Optical class as follows:
Q = quasar
B = BL Lac
G = radio galaxy
N = Narrow Line Seyfert 1 (NLSy1)
Note (3): Notes as follows:
a = Doppler factor value is from Liodakis et al. (2017MNRAS.466.4625L 2017MNRAS.466.4625L)
b = Assumed theta value as typical for BL Lacs
c = Assumed theta value as typical for radio galaxies in the list which
do not show a strong counterjet
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Source Source name (B1950)
10- 11 A2 --- Band [U UL] Observing band designations (1)
13- 15 F3.1 mas rmin Minimum core separation in fit
17- 21 F5.1 mas rmax maximum core separation in fit
23- 27 F5.3 --- alpha Fitted alpha-parameter (in mas1-k unit)
29- 33 F5.3 --- e_alpha Fitted alpha-parameter error (in mas1-k unit)
35- 40 F6.3 mas r0 Fitted r0 parameter
42- 46 F5.3 mas e_r0 Fitted r0 parameter error
48- 52 F5.3 --- k Fitted power-law index
54- 58 F5.3 --- e_k Fitted power-law index error
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Note (1): Observing band designation as follows:
U = only 15 GHz data used
UL = 15 and 1.4 GHz data used
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
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1- 41 A41 --- Ref Reference
43- 61 A19 --- BibCode BibCode
63- 85 A23 --- Com Comments
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Acknowledgements:
Alexander Pushkarev, pushkarev.alexander(at)gmail.com
(End) Patricia Vannier [CDS] 27-Mar-2023