J/A+A/669/A32 3C 84 multi-band study (Paraschos+, 2023)
A multi-band study and exploration of the radio wave-gamma-ray connection
in 3C 84.
Paraschos G.F., Mpisketzis V., Kim J.-Y., Witzel G., Krichbaum T.P.,
Zensus J.A., Gurwell M.A., Laehteenmaeki A., Tornikoski M., Kiehlmann S.,
Readhead A.C.S.
<Astron. Astrophys. 669, A32 (2023)>
=2023A&A...669A..32P 2023A&A...669A..32P (SIMBAD/NED BibCode)
ADC_Keywords: Active gal. nuclei ; Radio sources ; Interferometry ; Gamma rays
Keywords: galaxies: jets - galaxies: active -
galaxies: individual: 3C84 (NGC 1275) - techniques: interferometric -
techniques: high angular resolution
Abstract:
Total intensity variability light curves offer a unique insight into
the ongoing debate about the launching mechanism of jets. For this
work, we utilised the availability of radio and gamma-ray light curves
over a few decades of the radio source 3C 84 (NGC 1275). We calculated
the multi-band time-lags between the flares identified in the light
curves via discrete cross- correlation and Gaussian process
regression. We find that the jet particle and magnetic field energy
densities are in equipartition (kr=1.08±0.18). The jet apex is
located z91.5GHz=22-645Rs (2-20x10-3pc) upstream of the 3mm radio
core; at that position, the magnetic field amplitude is B91.5GHz core
=3-10G. Our results are in good agreement with earlier studies that
utilised very-long-baseline interferometry. Furthermore, we
investigated the temporal relation between the ejection of radio and
gamma-ray flares. Our results are in favour of the gamma-ray emission
being associated with the radio emission. We are able to tentatively
connect the ejection of features identified at 43 and 86GHz to
prominent gamma-ray flares. Finally, we computed the multiplicity
parameter λ and the Michel magnetisation σM, and find
that they are consistent with a jet launched by the Blandford & Znajek
(2007MNRAS.377L..49K 2007MNRAS.377L..49K) mechanism.
Description:
Total variability light-curves of 3C84 at 4.8, 8.0, 14.8 (UMRAO), 15
(OVRO), 37 (MRO), 91.5 (ALMA), 230 & 345 (SMA) GHz and gamma-ray light
curve (FERMI- LAT).
Objects:
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RA (2000) DE Designation(s)
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03 19 48.16 +41 30 42.1 3C 84 = NGC 1275
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
umrao.dat 35 4505 UMRAO 4.8, 8.0 & 14.8 GHz
ovro.dat 57 784 OVRO 15 GHz
mro.dat 59 8907 MRO 37 GHz
alma.dat 200 492 ALMA 91.5 GHz
sma.dat 54 866 SMA 230 & 345 GHz
gamma.dat 81 689 FERMI-LAT gamma-rays
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See also:
J/A+A/622/A196 : GMVA 86GHz Stokes IQU images of 3C84 jet (Kim+, 2019)
Byte-by-byte Description of file: umrao.dat
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Bytes Format Units Label Explanations
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1- 10 A10 "date" Obs.date Observation date
12- 15 F4.1 GHz Freq Frequency (4.8, 8.0 or 14.5)
17- 22 F6.3 --- UT U.T.
24- 28 F5.2 Jy S Flux density at Freq
30- 33 F4.2 Jy e_S Error on Flux density at Freq
35 I1 --- N [1/8] N
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Byte-by-byte Description of file: ovro.dat
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Bytes Format Units Label Explanations
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1- 18 F18.12 d MJD [54473.03/58871.3] MJD observation date
20- 37 F18.15 Jy Flux [13.78/41.93] Flux at 15GHz
39- 57 F19.17 Jy e_Flux [0.11/1.68] Flux at 15GHz error
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Byte-by-byte Description of file: mro.dat
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Bytes Format Units Label Explanations
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1- 11 F11.6 yr Date [1979.81/2021.75] Time (Decimal year)
13- 31 A19 --- Time Time
33- 36 A4 --- Source Source
38- 39 I2 GHz Freq [37] Frequency
41- 48 A8 --- Catalog Catalog (Kurp or KURP-GIX)
50- 54 F5.2 Jy Flux [7.13/60.53] Flux at 37GHz
56- 59 F4.2 Jy e_Flux [0.1/2.03] Error on Flux at 37GHz
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Byte-by-byte Description of file: alma.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- Band Band (ALMA-Band 3, ALMA-Band 6 or ALMA-Band 7)
13- 16 A4 --- Cat Catalogue name
18- 37 A20 --- Obs.date Observation date
39- 40 I2 h RAh Right ascension (J2000)
42- 43 I2 min RAm Right ascension (J2000)
45- 52 F8.5 s RAs Right ascension (J2000)
54- 73 E20.16 arcsec e_RAs [0.0/0.01] Right ascension uncertainty
75 A1 --- DE- Declination sign (J2000)
76- 77 I2 deg DEd Declination (J2000)
79- 80 I2 arcmin DEm Declination (J2000)
82- 88 F7.4 arcsec DEs Declination (J2000)
90-110 E21.16 arcsec e_DEs [0.0/0.01] Declination uncertainty
112-117 F6.3 Jy Flux [3.8/26.1] Flux density at Band
119-126 F8.6 Jy e_Flux [0.09/2.43] Flux density at Band uncertainty
128-136 E9.5 Hz Freq [91460000000.0/349500000000.0] Frequency
138-140 A3 deg --- [-] Separation
143-149 F7.1 --- MaxUV ?=- UV Max (in klambda unit)
151-200 A50 --- Names Names (separated by |)
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Byte-by-byte Description of file: sma.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- Band Band (1mm or 850)
5- 15 A11 "date" Obs.date UT observation date
17- 21 A5 "h:m" Obs.time Time (hh:mm)
23- 25 A3 --- Inst [SMA] Instrument
27- 32 F6.2 GHz Freq [205.99/362.48] Frequency
34- 39 F6.3 Jy Flux [0.08/17.12] Flux at Freq
41- 45 F5.3 Jy e_Flux [0.1/1.26] Error on Flux at Freq
47- 54 A8 --- PI P.I. for flux
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Byte-by-byte Description of file: gamma.dat
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Bytes Format Units Label Explanations
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1- 11 A11 "date" Date Date (UTC)
13- 19 I7 d JD [2454687/2459559] Julian Date
21- 29 I9 --- MET Mission elapsed time
31- 37 F7.2 s TS Total duration
39 A1 --- l_PhFlux Limit flag on PhotonFlux
40- 47 E8.4 ph/cm2/s PhFlux Photon Flux in 0.1-100GeV band
49- 55 E7.3 ph/cm2/s e_PhFlux ?=- Error on PhFlux
57- 61 F5.2 --- phIndex ?=- Photon Index
63- 66 E4.1 --- FitTol [0.0/0.01]?=- Fit Tolerance
68- 70 I3 --- MINUIT MINUIT Return Code
72- 81 A10 --- AnalysisLog Analysis Log
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Acknowledgements:
Georgios Filippos Paraschos, gfparaschos(at)mpifr.de
(End) Patricia Vannier [CDS] 09-Nov-2022