2011MNRAS.413..852G


Query : 2011MNRAS.413..852G

2011MNRAS.413..852G - Mon. Not. R. Astron. Soc., 413, 852-862 (2011/May-2)

The radio–γ-ray connection in Fermi blazars.

GHIRLANDA G., GHISELLINI G., TAVECCHIO F., FOSCHINI L. and BONNOLI G.

Abstract (from CDS):

We study the correlation between the γ-ray flux (Fγ), averaged over the first 11 months of the Fermi survey and integrated above 100 MeV, and the radio flux density (Fr at 20 GHz) of Fermi sources associated with a radio counterpart in the 20-GHz Australia Telescope Compact Array (AT20G) survey. Considering the blazars detected in both bands, the correlation is highly significant and has the form FγF0.85±0.04r, similar to BL Lacertae objects and flat-spectrum radio quasars. However, only a small fraction (∼1/15) of the AT20G radio sources with flat radio spectra are detected by Fermi. To understand if this correlation is real, we examine the selection effects introduced by the flux limits of both the radio and the γ-ray surveys, and the importance of variability of the γ-ray flux. After accounting for these effects, we find that the radio-γ-ray flux correlation is real, but its slope is steeper than the observed one, that is, FγFδr with δ in the range 1.25-1.5. The observed Fγ-Fr correlation and the fraction of radio sources detected by Fermi are reproduced assuming a long-term γ-ray flux variability, following a lognormal probability distribution with standard deviation σ ≥ 0.5 (corresponding to Fγ varying by at least a factor of 3). Such a variability is compatible, even if not necessarily equal, with what is observed when comparing, for the sources in common, the EGRET and the Fermi γ-ray fluxes (even if the Fermi fluxes are averaged over ∼1 yr). Another indication of variability is the non-detection of 12 out of 66 EGRET blazars by Fermi, despite its higher sensitivity. We also study the strong linear correlation between the γ-ray and the radio luminosity of the 144 AT20G-Fermi associations with known redshift and show, through partial correlation analysis, that it is statistically robust. Two possible implications of these correlations are discussed: the contribution of blazars to the extragalactic γ-ray background and the prediction of blazars that might undergo extremely high states of γ-ray emission in the next few years.

Abstract Copyright: 2011 The Authors Monthly Notices of the Royal Astronomical Society2011 RAS

Journal keyword(s): radiation mechanisms: non-thermal - BL Lacertae objects: general - quasars: general - radio continuum: general - X-rays: general

Simbad objects: 48

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Number of rows : 48
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2023
#notes
1 NGC 253 SyG 00 47 33.134 -25 17 19.68   8.03   6.94 8.1 ~ 3175 2
2 7C 0059+5808 QSO 01 02 45.76237340 +58 24 11.1366164   20.09 19.22 18.57 17.90 ~ 210 1
3 4C 01.02 Bla 01 08 38.77110544 +01 35 00.3171844   18.54 18.39 19.05   ~ 506 1
4 QSO B0208-512 BLL 02 10 46.2004407600 -51 01 01.893013392   17.10 16.93 14.82   ~ 417 1
5 4C 28.07 QSO 02 37 52.40567519 +28 48 08.9899986     18.5 16.99   ~ 565 1
6 4C 50.11 QSO 03 59 29.74727351 +50 57 50.1618607           ~ 421 1
7 QSO J0403-3605 QSO 04 03 53.74990003 -36 05 01.9131880   17.04 17.17 16.67   ~ 259 1
8 QSO B0420-0127 QSO 04 23 15.80072217 -01 20 33.0656073   17.50 17.00 16.28   ~ 1145 3
9 QSO B0454-463 QSO 04 55 50.77248730 -46 15 58.6797903   17.89 17.4 16.87   ~ 202 1
10 QSO J0457-2324 QSO 04 57 03.1791422424 -23 24 52.021129572   18.85 18.5 16.56   ~ 368 1
11 QSO B0521-365 BLL 05 22 57.98464178 -36 27 30.8512953   15.26 14.62 14.48   ~ 789 2
12 QSO B0537-441 BLL 05 38 50.36155950 -44 05 08.9390233   15.77 16.48 16   ~ 847 2
13 CRATES J060940-061538 Rad 06 09 40.0 -06 15 38           ~ 2 0
14 QSO B0607-157 QSO 06 09 40.94954062 -15 42 40.6727537   18.47 18.0 19.90   ~ 301 1
15 QSO B0625-354 BLL 06 27 06.7286533392 -35 29 15.363665088   14.93       ~ 171 1
16 QSO J0635-7516 QSO 06 35 46.5079301472 -75 16 16.816418256   15.96 15.75 15.82   ~ 555 1
17 7C 064253.00+445430.00 QSO 06 46 32.02599653 +44 51 16.5901185   19.57 18.49 18.64   ~ 336 1
18 QSO J0730-116 QSO 07 30 19.11247452 -11 41 12.6006642     20.30 20.3   ~ 283 1
19 QSO J0738+1742 BLL 07 38 07.39375312 +17 42 18.9981506   16.76 16.22 15.78   ~ 953 1
20 QSO J0854+2006 BLL 08 54 48.8749846272 +20 06 30.639583620   15.91 15.43 15.56   ~ 2210 1
21 ICRF J092703.0+390220 Sy1 09 27 03.01394144 +39 02 20.8518067   17.17 17.00 16.486   ~ 969 1
22 M 82 IG 09 55 52.430 +69 40 46.93 9.61 9.30 8.41     ~ 5657 6
23 4C 01.28 BLL 10 58 29.60520810 +01 33 58.8237454   18.74 18.28 16.68   ~ 727 2
24 4C 21.35 Bla 12 24 54.4583146056 +21 22 46.385507388   17.56 17.50 18.2   ~ 641 2
25 3C 273 BLL 12 29 06.6998257176 +02 03 08.597629980   13.05 14.830 14.11   ~ 5616 1
26 3C 279 Bla 12 56 11.16657958 -05 47 21.5251510   18.01 17.75 15.87   ~ 2909 2
27 NGC 4945 Sy2 13 05 27.279 -49 28 04.44   9.31 14.40 7.55   ~ 1390 2
28 7C 1308+3236 BLL 13 10 28.66385420 +32 20 43.7828340   15.61 15.24 17.91   ~ 810 1
29 NAME Centaurus A Sy2 13 25 27.61521044 -43 01 08.8050291   8.18 6.84 6.66   ~ 4302 3
30 QSO B1334-127 QSO 13 37 39.78278132 -12 57 24.6933925   18.5 18.5 16.22   ~ 465 1
31 QSO J1512-0906 Bla 15 12 50.53293048 -09 05 59.8297908   16.74 16.54     ~ 1249 1
32 QSO B1514-24 BLL 15 17 41.8134049824 -24 22 19.482207024   15.13 14.00 13.95   ~ 713 3
33 6C 161147+342017 QSO 16 13 41.06424322 +34 12 47.9088535   17.98 17.46 17.07   ~ 607 1
34 3C 345 QSO 16 42 58.80997043 +39 48 36.9939552   16.81 16.59 16.84   ~ 1650 2
35 4C 09.57 BLL 17 51 32.81857326 +09 39 00.7284066   17.46 16.78 15.57   ~ 894 1
36 QSO B1830-211 Bla 18 33 39.9399138048 -21 03 39.368838780     18.70 21   ~ 625 1
37 QSO B1921-293 BLL 19 24 51.05595254 -29 14 30.1210248   18.71 18.21 15.07   ~ 796 0
38 4C 73.18 BLL 19 27 48.4947009120 +73 58 01.572558816     15.5 15.11   ~ 512 2
39 QSO B1954-388 QSO 19 57 59.81927491 -38 45 06.3558881   18.47 17.07 16.73   ~ 202 1
40 QSO B2005+40 QSO 20 07 44.9449261536 +40 29 48.603352020   18.5 19 20.3   ~ 288 1
41 ICRF J200755.1-443444 Sy1 20 07 55.1842447944 -44 34 44.274118260   19.3 19.3 18   ~ 159 1
42 QSO B2134+0028 QSO 21 36 38.58632232 +00 41 54.2128562   17.30 17.08 17.02   ~ 547 2
43 4C 06.69 QSO 21 48 05.45866779 +06 57 38.6041877   16.85 16.47 15.06   ~ 637 1
44 NAME BL Lac BLL 22 02 43.2913536816 +42 16 39.979416792   15.66 14.72     ~ 2161 1
45 4C 31.63 BLL 22 03 14.9756830008 +31 45 38.269473228   15.85 15.58 14.33   ~ 478 1
46 3C 446 BLL 22 25 47.25929101 -04 57 01.3907626   18.83 18.39 16.3   ~ 799 1
47 AT20G J222940-083254 QSO 22 29 40.08433313 -08 32 54.4355294   17.80 17.41 17.81   ~ 326 1
48 3C 454.3 Bla 22 53 57.7480438728 +16 08 53.561508864   16.57 16.10 15.22   ~ 2719 2

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2022.11.30-17:43:48

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