J/A+A/670/A22 Compact jets in LLAGN (Fernandez-Ontiveros+, 2023)
Compact jets dominate the continuum emission in low-luminosity
active galactic nuclei.
Fernandez-Ontiveros J.A., Lopez-Lopez X., Prieto A.
<Astron. Astrophys. 670, A22 (2023)>
=2023A&A...670A..22F 2023A&A...670A..22F (SIMBAD/NED BibCode)
ADC_Keywords: Accretion ; Active gal. nuclei ; Galaxies, IR ;
Energy distributions ; Interstellar medium
Keywords: galaxies: active - galaxies: nuclei - galaxies: jets - infrared: ISM -
radiation mechanisms: non-thermal -
techniques: high angular resolution
Abstract:
The disappearance of the accretion disc in low-luminosity active
galactic nuclei (LLAGN) leaves behind a faint optical nuclear
continuum whose nature has been largely debated, mainly due to serious
observational limitations in the IR to UV range. We combine
multi-wavelength sub-arcsecond resolution observations -able to
isolate the genuine nuclear continuum- with nebular lines in the
mid-IR, to indirectly probe the shape of the extreme UV continuum. We
found that 8 of the nearest prototype LLAGN are compatible with pure
compact jet emission (self-absorbed synchrotron plus the associated
self-Compton component) over more than ten orders of magnitude in
frequency. When compared with typical radio galaxies, the LLAGN
continua show two peculiarities: i) a very steep spectral slope in the
IR-to-optical/UV range (-3.7<a0←1.3; Fnu∼nua0); and ii) a very
high turnover frequency (0.2-30THz; 1.3mm-10-micron). These attributes
can be explained if the synchrotron continuum is mainly dominated by
thermalised particles at the jet base or corona with considerably high
temperatures, whereas only a small fraction of the energy (∼20%) would
be distributed along the high-energy power-law tail of accelerated
particles. On the other hand, the nebular gas excitation in LLAGN is
in agreement with photo-ionisation from inverse Compton radiation
(ax~-0.7), which would dominate the nuclear continuum shortwards of
∼3000Å. Our results suggest that the LLAGN continuum can be
dominated at all wavelengths by undeveloped jets, powered by a
thermalised particle distribution, similar to the case of compact jets
in quiescent black hole X-ray binaries. This has important
implications in the context of galaxy evolution, since LLAGN may
represent a major but underestimated source of kinetic feedback in
galaxies.
Description:
Tables A1-A9: These tables include multi-wavelength high-angular
resolution measurements of the continuum emission for a sample of 9
low-luminosity AGN. The table columns correspond to the continuum
frequency, flux density and its associated error, aperture or beam
size, observation date, telescope/instruments and references.
Tables B1-B9: These tables include multi-wavelength large aperture
measurements of the continuum emission for a sample of 9
low-luminosity AGN. The table columns correspond to the continuum
frequency, flux density, aperture or beam size, telescope/instrument
and references.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
sources.dat 56 9 List of studied low-luminosity active
galactic nuclei
tablea1.dat 123 39 Sub-arcsecond aperture flux distribution
for NGC 4594
tablea2.dat 123 29 Sub-arcsecond aperture flux distribution
for M87
tablea3.dat 123 25 Sub-arcsecond aperture flux distribution
for NGC 4261
tablea4.dat 123 12 Sub-arcsecond aperture flux distribution
for NGC 3169
tablea5.dat 123 35 Sub-arcsecond aperture flux distribution
for NGC 4579
tablea6.dat 123 54 Sub-arcsecond aperture flux distribution
for NGC 1052
tablea7.dat 123 39 Sub-arcsecond aperture flux distribution
for NGC 1097
tablea8.dat 123 17 Sub-arcsecond aperture flux distribution
for NGC 1386
tablea9.dat 123 20 Sub-arcsecond aperture flux distribution
for NGC 404
tableb1.dat 89 42 Large aperture flux distribution for NGC 4594
tableb2.dat 89 35 Large aperture flux distribution for M87
tableb3.dat 89 70 Large aperture flux distribution for NGC 4261
tableb4.dat 89 31 Large aperture flux distribution for NGC 3169
tableb5.dat 89 44 Large aperture flux distribution for NGC 4579
tableb6.dat 89 55 Large aperture flux distribution for NGC 1052
tableb7.dat 89 32 Large aperture flux distribution for NGC 1097
tableb8.dat 89 56 Large aperture flux distribution for NGC 1386
tableb9.dat 89 38 Large aperture flux distribution for NGC 404
refs.dat 83 178 References
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Byte-by-byte Description of file: sources.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- Name Low-luminosity active galactic nuclei name
10- 11 I2 h RAh Simbad right ascension (J2000)
13- 14 I2 min RAm Simbad right ascension (J2000)
16- 20 F5.2 s RAs Simbad right ascension (J2000)
22 A1 --- DE- Declination sign (J2000)
23- 24 I2 deg DEd Declination (J2000)
26- 27 I2 arcmin DEm Declination (J2000)
29- 32 F4.1 arcsec DEs Declination (J2000)
34- 44 A11 --- tablea Name of the file with sub-arcsecond aperture
flux distribution
46- 56 A11 --- tableb Name of the file with large aperture
flux distribution
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Byte-by-byte Description of file: tablea?.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 15 E15.8 Hz nu Frequency
17- 24 E8.4 mJy Fn Sub-arcsec flux density
26- 33 E8.4 mJy e_Fn ?=- Sub-arcsec flux density error
35- 51 A17 arcsec Aper/Beam Aperture size or beam resolution
53- 74 A22 --- Date Observation date
75-117 A43 --- Notes Observing facility, instrument
119-123 A5 --- Ref Reference, in refs.dat
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Byte-by-byte Description of file: tableb?.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 14 E14.6 Hz nu Frequency
16- 23 E8.3 mJy Fn Large aperture flux density
25- 33 A9 arcsec Aper/Beam Aperture size or beam resolution
35- 83 A49 --- Notes Observing facility, instrument
85- 89 A5 --- Ref Reference, in refs.dat file
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Byte-by-byte Description of file: refs.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 A5 --- Ref Reference code
7- 25 A19 --- BibCode BibCode
27- 54 A28 --- Aut Author's name
56- 83 A28 --- Com Comments
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Acknowledgements:
Juan Antonio Fernandez Ontiveros, j.a.fernandez.ontiveros(at)gmail.com
(End) J.A. Fernandez Ontiveros [CEFCA, Spain], P. Vannier [CDS] 24-Jan-2023