2011AJ....142..108K

Query : 2011AJ....142..108K

2011AJ....142..108K - Astron. J., 142, 108 (2011/October-0)

Dual-frequency observations of 140 compact, flat-spectrum active galactic nuclei for scintillation-induced variability.

KOAY J.Y., MacQUART J.-P., RICKETT B.J., BIGNALL H.E., LOVELL J.E.J., REYNOLDS C., JAUNCEY D.L., PURSIMO T., KEDZIORA-CHUDCZER L. and OJHA R.

Abstract (from CDS):

The 4.9 GHz Micro-Arcsecond Scintillation-Induced Variability (MASIV) Survey detected a drop in interstellar scintillation (ISS) for sources at redshifts z ≳ 2, indicating an apparent increase in angular diameter or a decrease in flux density of the most compact components of these sources relative to their extended emission. This can result from intrinsic source size effects or scatter broadening in the intergalactic medium (IGM) in excess of the expected (1 + z)1/2 angular diameter scaling of brightness temperature limited sources resulting from cosmological expansion. We report here 4.9 GHz and 8.4 GHz observations and data analysis for a sample of 140 compact, flat-spectrum sources which may allow us to determine the origin of this angular diameter-redshift relation by exploiting their different wavelength dependences. In addition to using ISS as a cosmological probe, the observations provide additional insight into source morphologies and the characteristics of ISS. As in the MASIV Survey, the variability of the sources is found to be significantly correlated with line-of-sight Hα intensities, confirming its link with ISS. For 25 sources, time delays of about 0.15-3 days are observed between the scintillation patterns at both frequencies, interpreted as being caused by a shift in core positions when probed at different optical depths. Significant correlation is found between ISS amplitudes and source spectral index; in particular, a large drop in ISS amplitudes is observed at α < -0.4 confirming that steep spectrum sources scintillate less. We detect a weakened redshift dependence of ISS at 8.4 GHz over that at 4.9 GHz, with the mean variance at four-day timescales reduced by a factor of 1.8 in the z > 2 sources relative to the z < 2 sources, as opposed to the factor of three decrease observed at 4.9 GHz. This suggests scatter broadening in the IGM, but the interpretation is complicated by subtle selection effects that will be explored further in a follow-up paper.

Abstract Copyright: ∼

Journal keyword(s): galaxies: active - intergalactic medium - ISM: structure - methods: data analysis - quasars: general - radio continuum: ISM

VizieR on-line data: <Available at CDS (J/AJ/142/108): table2.dat>

Simbad objects: 130

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Number of rows : 130
N Identifier Otype ICRS (J2000)
RA 		ICRS (J2000)
DEC 		Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2024 		#notes
1 MASIV J0009+1513 AGN 00 09 43.47 +15 13 37.9           ~ 3 0
2 6C 001403+811827 BLL 00 17 08.47489694 +81 35 08.1365094   17.60 16.52 15.95   ~ 389 1
3 ICRF J001751.7+531219 QSO 00 17 51.7596321384 +53 12 19.121143824           ~ 23 1
4 QSO J0056+1625 BLL 00 56 55.29432895 +16 25 13.3409138       19.51   ~ 41 1
5 4C 01.02 Bla 01 08 38.77110544 +01 35 00.3171844   18.54 18.39 19.05   ~ 545 1
6 [VV2006] J012201.9+031003 QSO 01 22 01.9106 +03 10 02.431     20.07 20   ~ 19 1
7 QSO B0119+247 QSO 01 22 38.81598441 +25 02 31.7927370     18.5 17.91   ~ 66 1
8 4C 25.05 Bla 01 26 42.79263357 +25 59 01.3001559     17.50 17.86   ~ 166 1
9 BWE 0133+2142 QSO 01 35 53.4945 +21 58 16.152           ~ 6 1
10 [VV96] J015456.3+474327 QSO 01 54 56.28988519 +47 43 26.5396113       18.97   ~ 48 1
11 6C 021252+733537 BLL 02 17 30.81335327 +73 49 32.6217355     19.00 18.97   ~ 456 1
12 ICRF J023750.6+204618 QSO 02 37 50.62892607 +20 46 18.4555879           ~ 12 1
13 QSO B0235+1624 BLL 02 38 38.93010450 +16 36 59.2745528   16.46 15.50 15.92   ~ 1549 2
14 QSO B0239+108 QSO 02 42 29.17085078 +11 01 00.7279391   20.0   19.66   ~ 125 1
15 QSO J0259+1925 QSO 02 59 29.65594445 +19 25 44.3272958       19   ~ 32 1
16 MASIV J0308+1208 AGN 03 08 39.38 +12 08 49.7           ~ 3 0
17 ICRF J031313.4+022835 QSO 03 13 13.40546775 +02 28 35.3066546           ~ 25 0
18 QSO B0319+12 QSO 03 21 53.10350560 +12 21 13.9537765   19 19     ~ 133 1
19 ICRF J032314.7+044612 QSO 03 23 14.7229685544 +04 46 12.571169520           ~ 22 1
20 3FHL J0342.2+3858 BLL 03 42 16.26 +38 59 06.2       19.5   ~ 35 0
21 6C 034014+361233 QSO 03 43 28.95241581 +36 22 12.4297151     20.80 19.78   ~ 78 1
22 MASIV J0358+3850 AGN 03 58 44.43 +38 50 21.6           ~ 3 0
23 QSO B0400+258 QSO 04 03 05.58608082 +26 00 01.5027775     18 19.00   ~ 206 1
24 [VV98] J040626.0+251130 QSO 04 06 25.9973252448 +25 11 31.191296748     19.90     ~ 8 0
25 QSO B0406+121 BLL 04 09 22.00871072 +12 17 39.8476330   20.5   18.27   ~ 105 1
26 QSO B0420+022 BLL 04 22 52.21465085 +02 19 26.9307480     19.5 19.41   ~ 99 1
27 QSO B0446+113 BLL 04 49 07.67110194 +11 21 28.5963618     20.00 18.58   ~ 274 1
28 QSO J0459+0229 QSO 04 59 52.05066296 +02 29 31.1765162   18.2 19     ~ 163 1
29 QSO B0507+179 QSO 05 10 02.36912937 +18 00 41.5815635   20.0 19.0 19.09   ~ 434 1
30 QSO J0530+13 Bla 05 30 56.41674741 +13 31 55.1494688     20.00 19.35   ~ 960 1
31 BWE 0531+1045 AGN 05 34 40.7276789568 +10 47 16.521928044           ~ 6 1
32 ICRF J053942.3+143345 QSO 05 39 42.36599322 +14 33 45.5616887           ~ 87 1
33 8C 0609+607 QSO 06 14 23.86617701 +60 46 21.7559176   20 19.1 18.8   ~ 71 1
34 7C 062051.50+385829.00 QSO 06 24 19.02128805 +38 56 48.7360344   20.0 20.0 19.24   ~ 78 1
35 7C 064253.00+445430.00 QSO 06 46 32.02599653 +44 51 16.5901185   19.57 18.49 18.64   ~ 348 1
36 ICRF J065917.9+081330 QSO 06 59 17.99603181 +08 13 30.9534246           ~ 33 1
37 87GB 072222.1+613123 AGN 07 26 51.6789 +61 25 13.683           ~ 6 1
38 7C 073246.29+753437.00 QSO 07 39 13.19478577 +75 27 47.7091154           ~ 16 1
39 QSO B0736+01 QSO 07 39 18.03389906 +01 37 04.6177501   16.90 16.47 16.19   ~ 688 1
40 2MASS J07412972+2557318 QSO 07 41 29.7417750048 +25 57 32.258962692       19.1   ~ 20 0
41 QSO B0742+103 QSO 07 45 33.05952486 +10 11 12.6922178     24.00 23.72   ~ 192 1
42 QSO B0748+126 QSO 07 50 52.04573865 +12 31 04.8282079   17.67 17.28 17.16   ~ 335 1
43 QSO B0754+10 BLL 07 57 06.64295154 +09 56 34.8522544   15.43 15.00 15.99   ~ 440 1
44 SDSS J080034.34+485424.2 QSO 08 00 34.3735 +48 54 24.011           ~ 18 1
45 6C 080047+615309 Bla 08 05 18.17956222 +61 44 23.7005580       19.64   ~ 135 1
46 ICRF J081026.4+101040 BLL 08 10 26.4238989360 +10 10 40.998553320   18.10 17.87     ~ 34 0
47 QSO B0808+019 BLL 08 11 26.70731711 +01 46 52.2201568   17.58 17.2 17.96   ~ 243 1
48 7C 081451.89+423206.00 BLL 08 18 15.99961476 +42 22 45.4148987   18.88 18.18 17.81   ~ 401 1
49 QSO J0821+3107 BLL 08 21 07.6135883448 +31 07 51.147374376   17.59 17.28     ~ 68 1
50 QSO B0823+033 BLL 08 25 50.33835759 +03 09 24.5199749   17.81 17.23 16.91   ~ 330 1
51 QSO J0850+5159 QSO 08 50 42.2440214784 +51 59 11.650187472   19.92 19.41     ~ 48 1
52 6C 084720+804537 QSO 08 54 48.5990118096 +80 34 22.383839496           ~ 20 1
53 ICRF J085654.8+714623 QSO 08 56 54.86854258 +71 46 23.9031213           ~ 51 1
54 ICRF J091437.9+024559 Sy1 09 14 37.91343881 +02 45 59.2464510   19.94 19.74 19.2   ~ 103 1
55 ICRF J091641.7+024252 Sy1 09 16 41.76666992 +02 42 52.9013196   19.43 19.15     ~ 34 1
56 6C 091740+445437 Bla 09 20 58.45848666 +44 41 53.9850947   18.40 18.16 16.55   ~ 380 1
57 6C 092554+502611 BLL 09 29 15.4401569832 +50 13 35.990913000   17.18 16.80 15.94   ~ 145 2
58 ICRF J095359.2+172056 Bla 09 53 59.2310353056 +17 20 56.658544764   18.77 18.62 18.5   ~ 45 0
59 US 1139 QSO 09 58 19.67164698 +47 25 07.8424065   18.78 18.62 18.39   ~ 241 1
60 6C 095456+654857 BLL 09 58 47.2451872176 +65 33 54.819354600     17.0 15.75   ~ 713 1
61 QSO J1007+1356 QSO 10 07 41.49808928 +13 56 29.6007670     19.0 18.59   ~ 123 1
62 7C 101358.5+205256 QSO 10 16 44.32210575 +20 37 47.3053485   19.67 19.41 18.67   ~ 82 1
63 ICRF J104946.3+142938 BLL 10 49 46.32757946 +14 29 38.5737464           ~ 20 1
64 6C 105327+702759 QSO 10 56 53.61750640 +70 11 45.9155652   18.5 18.5 19.32   ~ 112 1
65 CTD 74 Bla 11 25 53.71191677 +26 10 19.9787016   18.62 18.51 18.39   ~ 146 1
66 Ton 599 Sy1 11 59 31.83391383 +29 14 43.8268224   14.80 14.41 17.652 13.39 ~ 926 1
67 ICRF J124707.5+704645 QSO 12 47 07.55260236 +70 46 45.1213497           ~ 18 1
68 QSO J1300-3253 QSO 13 00 42.4259780568 -32 53 12.114395844     18.70 18   ~ 84 1
69 87GB 131449.5+694301 AGN 13 16 22.9811 +69 27 16.661           ~ 6 1
70 ICRF J132840.5+622137 Sy1 13 28 40.56423209 +62 21 37.0359699   19.53 19.13     ~ 38 2
71 SDSS J133029.38+495427.4 QSO 13 30 29.3888787432 +49 54 27.486301752   19.38 19.14     ~ 29 1
72 3C 286 Sy1 13 31 08.2883506368 +30 30 32.960091564   17.51 17.25     ~ 4342 2
73 8C 1353+670 QSO 13 54 23.0897270280 +66 45 25.621917120           ~ 10 1
74 [VV2006] J141031.0+614137 QSO 14 10 30.9913639152 +61 41 36.920763492   19.17 18.98     ~ 39 1
75 PB 1950 Sy1 14 17 40.4459790288 +38 18 21.141908100   18.73 18.64 18.1   ~ 56 1
76 8C 1435+638 QSO 14 36 45.8021325144 +63 36 37.866905244   17.06 16.86 16.23   ~ 212 1
77 6C 143538+512545 QSO 14 37 19.8000 +51 12 49.386           ~ 26 1
78 ICRF J144212.2+062526 QSO 14 42 12.23775093 +06 25 26.1339706           ~ 10 1
79 [VV98] J153514.8+483700 QSO 15 35 14.6533824696 +48 36 59.692793220   18.36 18.16     ~ 56 1
80 QSO B1547+507 QSO 15 49 17.46855793 +50 38 05.7880702   18.89 18.74 18.16   ~ 131 1
81 2MASS J15594972+0805177 QSO 15 59 49.7213508504 +08 05 17.575602720           ~ 19 1
82 ICRF J161050.6+780900 QSO 16 10 50.60469327 +78 09 00.5419013           ~ 15 1
83 QSO B1614+051 QSO 16 16 37.55681923 +04 59 32.7365717   19.60 19.17 19.49   ~ 186 2
84 QSO J1619+2247 QSO 16 19 14.82460190 +22 47 47.8509104       20.00   ~ 66 1
85 4C 41.32 QSO 16 25 57.66971273 +41 34 40.6292008     22 21.73   ~ 165 1
86 [VV2006] J163915.8+412833 QSO 16 39 15.8122 +41 28 33.702   19.36 19.16 19.04 18.90 ~ 38 1
87 [VV2006] J165913.9+171415 QSO 16 59 13.8590391576 +17 14 15.069995484   19.58 19.30     ~ 30 1
88 ICRF J170121.3+033851 QSO 17 01 21.37818791 +03 38 51.1754029           ~ 14 1
89 7C 1716+6839 QSO 17 16 13.93798667 +68 36 38.7451988   18.99 18.16 17.67   ~ 123 1
90 QSO B1717+178 BLL 17 19 13.04848035 +17 45 06.4371847   20.10 19.1 17.28   ~ 225 1
91 ICRF J171952.2+081703 QSO 17 19 52.2063161088 +08 17 03.554283336       15.87   ~ 36 1
92 ICRF J172824.9+042704 Sy1 17 28 24.95272284 +04 27 04.9138307   17.43 16.99 16.24   ~ 225 1
93 MITG J1733+1635 QSO 17 33 01.5442847832 +16 35 52.634715396   19.5 20.0     ~ 5 0
94 7C 173240.70+385949.00 BLL 17 34 20.57853650 +38 57 51.4430945   19.5 19 19.00   ~ 205 1
95 4C 51.37 Bla 17 40 36.97784792 +52 11 43.4073694   18.16 18.70 16.73   ~ 415 1
96 ICRF J174232.0+594506 BLL 17 42 31.9998615600 +59 45 06.731291412   17.74 17.14 16.7   ~ 83 1
97 2MASS J17452844+4059518 QSO 17 45 28.4547 +40 59 51.829           ~ 9 1
98 4C 09.57 BLL 17 51 32.81857326 +09 39 00.7284066   17.46 16.78 15.57   ~ 946 1
99 ICRF J175758.8+053148 BLL 17 57 58.82513908 +05 31 48.0245781           ~ 17 1
100 7C 175844.60+384828.00 QSO 18 00 24.76536016 +38 48 30.6974570   17.8 17.98 17.04   ~ 151 1
101 7C 1812+5602 QSO 18 12 57.66948926 +56 03 49.2000537           ~ 25 1
102 ICRF J181926.5+384501 SyG 18 19 26.54735971 +38 45 01.7860362           ~ 118 0
103 ICRF J183243.4+135744 QSO 18 32 43.47110199 +13 57 44.4005043       18.18   ~ 35 1
104 ICRF J183905.8+410059 QSO 18 39 05.8038562392 +41 00 59.096073024           ~ 24 1
105 QSO B1848+283 QSO 18 50 27.5898721080 +28 25 13.155071160   17.1 17 17.16   ~ 82 1
106 ICRF J190536.4+194308 QSO 19 05 36.47209537 +19 43 08.0450100           ~ 18 1
107 87GB 191718.9+315406 QSO 19 19 13.2333022128 +31 59 45.069607032           ~ 9 1
108 ICRF J193116.5+474341 QSO 19 31 16.54756682 +47 43 41.2037745           ~ 13 1
109 QSO J2002+4725 QSO 20 02 10.41824494 +47 25 28.7737471           ~ 41 1
110 [VV98] J200617.7+642445 QSO 20 06 17.69453821 +64 24 45.4180077     19.00 20.13   ~ 56 1
111 BWE 2011+7156 QSO 20 11 03.8210890656 +72 05 12.173472888           ~ 8 1
112 87GB 201138.8+630959 QSO 20 12 22.0231781880 +63 19 11.986665744           ~ 8 1
113 QSO J2016+1632 BLL 20 16 13.86003062 +16 32 34.1130371       17.29   ~ 40 1
114 ICRF J211354.7+112125 QSO 21 13 54.71451754 +11 21 25.3969387   19.5 20.0     ~ 13 1
115 ICRF J211636.6+053617 QSO 21 16 36.63486842 +05 36 17.0458950           ~ 26 0
116 QSO J2123+0535 QSO 21 23 44.51739933 +05 35 22.0930238   18.3 20.40 19.86   ~ 295 1
117 SDSS J213730.01+045122.1 QSO 21 37 30.0204571872 +04 51 22.166958492           ~ 15 1
118 QSO B2201+1711 BLL 22 03 26.89368237 +17 25 48.2477620     19.50 14.76   ~ 205 1
119 ICRF J220824.1+180826 QSO 22 08 24.1903686336 +18 08 26.839271184           ~ 16 0
120 QSO B2209+236 QSO 22 12 05.96631459 +23 55 40.5438259   19 20.66 19.69   ~ 231 1
121 BWE 2218+1102 QSO 22 21 19.1605495536 +11 17 41.939302020           ~ 6 1
122 ICRF J223704.2+421648 QSO 22 37 04.20971225 +42 16 48.2628262           ~ 16 1
123 QSO B2239+096 QSO 22 41 49.71731323 +09 53 52.4450634   19.72 19.22 18.00   ~ 60 1
124 ICRF J224215.1+295543 QSO 22 42 15.15119532 +29 55 43.1187478           ~ 11 0
125 ICRF J225312.4+323604 QSO 22 53 12.49980744 +32 36 04.3267691           ~ 22 1
126 87GB 225552.3+050024 QSO 22 58 24.6036172368 +05 16 39.176580108           ~ 13 1
127 BWE 2302+2654 QSO 23 04 29.4040328328 +27 10 31.099103148           ~ 7 1
128 6C 230937+452727 QSO 23 11 47.40897544 +45 43 56.0164210       19.19   ~ 61 1
129 8C 2316+862 QSO 23 15 49.8191012256 +86 31 43.594858452           ~ 18 1
130 ICRF J233929.7+024405 QSO 23 39 29.71060518 +02 44 05.3575285           ~ 23 1

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