2007A&A...469..899H

Query : 2007A&A...469..899H

2007A&A...469..899H - Astronomy and Astrophysics, volume 469899-912 (2007/7-3)

Statistical analyses of long-term variability of AGN at high radio frequencies.

HOVATTA T., TORNIKOSKI M., LAINELA M., LEHTO H.J., VALTAOJA E., TORNIAINEN I., ALLER M.F. and ALLER H.D.

Abstract (from CDS):

We present a study of variability time scales in a large sample of Active Galactic Nuclei at several frequencies between 4.8 and 230GHz. We investigate the differences of various AGN types and frequencies and correlate the measured time scales with physical parameters such as the luminosity and the Lorentz factor. Our sample consists of both high and low polarization quasars, BL Lacertae objects and radio galaxies. The basis of this work is the 22GHz, 37GHz and 87GHz monitoring data from the Metsaehovi Radio Observatory spanning over 25 years. In addition, we used higher 90GHz and 230GHz frequency data obtained with the SEST-telescope between 1987 and 2003. Further lower frequency data at 4.8GHz, 8GHz and 14.5GHz from the University of Michigan monitoring programme have been used. We have applied three different statistical methods to study the time scales: the structure function, the discrete correlation function and the Lomb-Scargle periodogram. We discuss also the differences and relative merits of these three methods. Our study reveals that smaller flux density variations occur in these sources on short time scales of 1-2 years, but larger outbursts happen quite rarely, on the average only once in every 6 years. We do not find any significant differences in the time scales between the source classes. The time scales are also only weakly related to the luminosity suggesting that the shock formation is caused by jet instabilities rather than the central black hole.

Abstract Copyright: ∼

Journal keyword(s): galaxies: active - methods: statistical

Simbad objects: 80

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Number of rows : 80
N Identifier Otype ICRS (J2000)
RA 		ICRS (J2000)
DEC 		Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2026 		#notes
1 Mrk 1501 Bla 00 10 31.00590413 +10 58 29.5042981   15.96 15.40 12.22   ~ 763 1
2 QSO B0016+73 Bla 00 19 45.78637230 +73 27 30.0176020     19.00 18.26   ~ 313 1
3 4C 01.02 Bla 01 08 38.77110544 +01 35 00.3171844   18.54 18.39 19.05   ~ 589 1
4 QSO B0109+224 BLL 01 12 05.8247044608 +22 44 38.785880796   16.00 15.66 15.47   ~ 373 2
5 6C 013354+473615 Bla 01 36 58.59480326 +47 51 29.1000720     19.50 19.25 15.21 ~ 537 1
6 QSO B0149+218 Bla 01 52 18.05904204 +22 07 07.6997943     18 18.89   ~ 201 1
7 4C 15.05 Bla 02 04 50.41389294 +15 14 11.0436097   21.9 21.00 21.00   ~ 426 1
8 6C 021252+733537 BLL 02 17 30.81335327 +73 49 32.6217355     19.00 18.97   ~ 485 1
9 4C 67.05 Bla 02 28 50.05148365 +67 21 03.0293322   19.5 19.50 18.1   ~ 264 1
10 4C 28.07 Bla 02 37 52.40567519 +28 48 08.9899986     19.30 16.99   ~ 654 1
11 QSO B0235+1624 BLL 02 38 38.93010450 +16 36 59.2745528   16.46 15.50 15.92   ~ 1614 2
12 6C 024820+430300 Bla 02 51 34.53674154 +43 15 15.8292024     18.0 13.72   ~ 221 1
13 NGC 1275 Bla 03 19 48.1599902040 +41 30 42.108850836   13.10 12.48 11.09   ~ 4243 3
14 6C 033321+320838 Bla 03 36 30.10760267 +32 18 29.3422162     17.50 16.6   ~ 688 1
15 QSO B0336-0156 Bla 03 39 30.93778633 -01 46 35.8041892   18.96 18.41 17.33   ~ 598 1
16 6C 035545+504923 Bla 03 59 29.74727351 +50 57 50.1618607           ~ 480 1
17 3C 111 Sy1 04 18 21.2772425736 +38 01 35.801359968   19.75 18.05     ~ 1002 2
18 QSO B0420-0127 Bla 04 23 15.80072217 -01 20 33.0656073   17.50 17.00 16.28   ~ 1263 3
19 QSO B0422+004 BLL 04 24 46.8421990080 +00 36 06.329375028 16.15 15.94 16.98     ~ 378 1
20 MCG+01-12-009 Bla 04 33 11.0956735296 +05 21 15.619461552   15.72 15.05 10.08   ~ 2099 2
21 QSO B0446+113 BLL 04 49 07.67110194 +11 21 28.5963618     20.00 18.58   ~ 305 1
22 4C -02.19 Bla 05 01 12.80988538 -01 59 14.2564557   19.1 18.06 19.04   ~ 624 1
23 QSO J0530+13 Bla 05 30 56.41674741 +13 31 55.1494688     20.00 19.35   ~ 1004 1
24 7C 055201.39+394824.00 Bla 05 55 30.80561419 +39 48 49.1649683     18.30 17.5   ~ 527 2
25 7C 064253.00+445430.00 Bla 06 46 32.02599653 +44 51 16.5901185   19.57 18.49 18.64   ~ 370 1
26 8C 0716+714 BLL 07 21 53.4482942664 +71 20 36.363846516   15.5 15.50 14.27   ~ 1388 1
27 QSO J0738+1742 BLL 07 38 07.39375312 +17 42 18.9981506   16.76 16.22 15.78   ~ 1045 1
28 QSO B0736+01 Bla 07 39 18.03389906 +01 37 04.6177501   16.90 16.47 16.19   ~ 738 1
29 QSO B0754+10 BLL 07 57 06.64295154 +09 56 34.8522544   15.43 15.00 15.99   ~ 461 1
30 7C 080458.39+495918.00 Bla 08 08 39.66628970 +49 50 36.5304041   19.55 19.18 18.34   ~ 389 2
31 7C 081451.89+423206.00 BLL 08 18 15.99961476 +42 22 45.4148987   18.88 18.18 17.81   ~ 429 1
32 7C 082754.29+242103.00 Bla 08 30 52.08619250 +24 10 59.8202919   17.62 17.26 16.30   ~ 563 1
33 4C 71.07 Bla 08 41 24.36528508 +70 53 42.1730435     17.30 16.8   ~ 818 1
34 PG 0851+202 BLL 08 54 48.8749846272 +20 06 30.639583620   15.649 15.146 15.446   ~ 2513 1
35 3C 216.0 Bla 09 09 33.49714902 +42 53 46.4821036   19.98 19.42 18.220   ~ 520 1
36 4C 39.25 Bla 09 27 03.01394144 +39 02 20.8518067   17.17 17.00 16.486   ~ 1036 1
37 4C 40.24 Bla 09 48 55.33815103 +40 39 44.5869471   18.31 18.02 17.85   ~ 379 1
38 7C 095359.3+252945 Bla 09 56 49.87537985 +25 15 16.0498155   17.46 17.21 17.96   ~ 367 2
39 4C 55.17 Bla 09 57 38.1839604096 +55 22 57.754950636   18.24 17.89     ~ 459 1
40 6C 095456+654857 BLL 09 58 47.2451872176 +65 33 54.819354600     17.0 15.75   ~ 771 1
41 4C 01.28 BLL 10 58 29.60520810 +01 33 58.8237454   18.74 18.28 16.68   ~ 828 2
42 Z 184-50 BLL 11 04 27.3140835504 +38 12 31.798495872   13.50 12.90 8.31   ~ 2841 1
43 7C 1147+2434 BLL 11 50 19.21218244 +24 17 53.8352318   16.26 15.74 15.80   ~ 294 1
44 Ton 599 Bla 11 59 31.83391383 +29 14 43.8268224   14.80 14.41 17.652 13.39 ~ 989 1
45 7C 1219+2830 BLL 12 21 31.6904439888 +28 13 58.500308172   16.81 16.11 14.24   ~ 924 1
46 7C 122223.5+213929 Bla 12 24 54.4583146056 +21 22 46.385507388   17.56 17.50 18.2   ~ 770 2
47 3C 273 BLL 12 29 06.6998257176 +02 03 08.597629980   13.05 14.830 14.11   ~ 6022 1
48 3C 279 Bla 12 56 11.16657958 -05 47 21.5251510   18.01 17.75 15.87   ~ 3205 2
49 US 371 BLL 13 10 28.66385420 +32 20 43.7828340   15.61 15.24 17.91   ~ 917 1
50 QSO B1413+135 BLL 14 15 58.81751033 +13 20 23.7128587   21.055 20.000 18.461   ~ 476 1
51 6C 141804+543700 BLL 14 19 46.5974051952 +54 23 14.787857796   16.17 15.65 14.16   ~ 630 1
52 QSO B1502+1041 Bla 15 04 24.97978391 +10 29 39.1985309   18.97 18.56 18.94   ~ 634 1
53 QSO J1512-0906 Bla 15 12 50.53293048 -09 05 59.8297908   16.74 16.54     ~ 1409 1
54 4C 14.60 BLL 15 40 49.49151924 +14 47 45.8846989   17.72 17.30 17.240   ~ 448 1
55 4C 10.45 Bla 16 08 46.20318700 +10 29 07.7757424   18.5 18.70 18.03   ~ 409 1
56 6C 161147+342017 Bla 16 13 41.06424322 +34 12 47.9088535   17.98 17.46 17.07   ~ 673 1
57 4C 38.41 Bla 16 35 15.49297809 +38 08 04.5005995   18.14 17.97 17.25   ~ 906 1
58 6C 163718+572618 Bla 16 38 13.45629995 +57 20 23.9789828     16.90 16.94   ~ 381 1
59 3C 345 Bla 16 42 58.80997043 +39 48 36.9939552   16.81 16.59 16.84   ~ 1808 3
60 Z 225-7 BLL 16 53 52.21668403 +39 45 36.6088754 14.09 14.15 13.29 8.26   ~ 2304 2
61 QSO B1725+044 Bla 17 28 24.95272284 +04 27 04.9138307   17.43 16.99 16.24   ~ 245 1
62 4C 51.37 Bla 17 40 36.97784792 +52 11 43.4073694   18.16 18.70 16.73   ~ 441 1
63 QSO B1741-038 Bla 17 43 58.85613537 -03 50 04.6167326     20.40 17.98   ~ 583 1
64 4C 09.57 BLL 17 51 32.81857326 +09 39 00.7284066   17.46 16.78 15.57   ~ 1007 1
65 1RXS J180043.6+782806 BLL 18 00 45.6838528560 +78 28 04.018028016   16.4 15.90 16.134   ~ 793 1
66 Z 340-35 BLL 18 06 50.6802916920 +69 49 28.109609256   14.77 14.22 11.39   ~ 909 1
67 4C 56.27 BLL 18 24 07.06837171 +56 51 01.4908155   18.9 19.30 16.48   ~ 510 1
68 4C 73.18 BLL 19 27 48.4947009120 +73 58 01.572558816     16.06 15.11   ~ 562 2
69 8C 2007+777 BLL 20 05 30.9987913056 +77 52 43.248139536     16.5 17.36   ~ 474 1
70 QSO B2005+40 Bla 20 07 44.9449261536 +40 29 48.603352020   18.5 19.00 20.3   ~ 319 1
71 QSO B2021+614 Bla 20 22 06.68174620 +61 36 58.8047323     19.00 17.58   ~ 335 1
72 QSO B2134+0028 Bla 21 36 38.58632232 +00 41 54.2128562   17.30 17.08 17.02   ~ 580 2
73 QSO B2136+1410 Bla 21 39 01.30926630 +14 23 35.9921774     18.90 18.22   ~ 264 1
74 4C 06.69 Bla 21 48 05.45866779 +06 57 38.6041877   16.85 16.47 15.06   ~ 703 1
75 NAME BL Lac BLL 22 02 43.2913536816 +42 16 39.979416792   15.66 14.72     ~ 2397 1
76 4C 31.63 BLL 22 03 14.9756830008 +31 45 38.269473228   15.85 15.58 14.33   ~ 523 1
77 3C 446 BLL 22 25 47.25929101 -04 57 01.3907626   18.83 18.39 16.3   ~ 863 1
78 4C 11.69 Bla 22 32 36.40890093 +11 43 50.9040592   17.75 17.33     ~ 1205 2
79 QSO B2232+282 BLL 22 36 22.47084387 +28 28 57.4132050   19.1 19.0 17.60   ~ 306 2
80 3C 454.3 Bla 22 53 57.7480438728 +16 08 53.561508864   16.57 16.10 15.22   ~ 3004 2

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