2011A&A...534A..59G


Query : 2011A&A...534A..59G

2011A&A...534A..59G - Astronomy and Astrophysics, volume 534A, 59-59 (2011/10-1)

The optical variability of steep-spectrum radio quasars in the SDSS stripe 82 region.

GU M.F. and AI Y.L.

Abstract (from CDS):

There have been many investigations of the optical variability of flat-spectrum radio quasars (FSRQs), but the optical variability of steep-spectrum radio quasars (SSRQs) has been poorly studied. We investigate the optical variability of SSRQs, comparing this with the optical variability of FSRQs. We measure the optical variability of 18 SSRQs and 15 FSRQs in the SDSS Stripe 82 region using SDSS DR7 released multi-epoch data covering about nine years. We determine the spectral index by fitting a power law to SDSS ugriz photometric data, and explore the relationship between this spectral index and source brightness. For all SSRQs studied, we detect variations in r band flux of overall amplitude between 0.22mag and 0.92mag in different sources. Eight of 18 SSRQs display a bluer-when-brighter (BWB) trend. In contrast, the variability amplitude of 15 FSRQs in r band ranges from 0.18 to 0.97mag, and 11 of 15 sources follow a BWB trend. For all SSRQs studied, we found an anti-correlation between the Eddington ratio and the variability amplitude in r band, which is similar to that in radio-quiet AGNs. This implies that the thermal emission from the accretion disk may be responsible for the variability in SSRQs, although the jet nonthermal emission cannot be excluded. In contrast, there is no correlation found for FSRQs, which implies that the mechanisms of variability in FSRQs may be different from that in SSRQs. The optical continuum variability of radio-loud broad absorption-line quasars (BALQs) are investigated for the first time here for two sources with steep radio spectra. Both radio-loud BALQs display variations with amplitudes of about 0.3mag at r band. Their spectral variability all follow a BWB trend. In our previous analysis of a combined sample of 18 SSRQs and 44 FSRQs, we found that the line width of the broad MgII emission line is broader for steeper radio spectral indices. It implies a disk-like broad line region (BLR) geometry may present in these quasars. In these 62 quasars, we found a ∼57% source percentage showing BWB trend in FSRQs, whereas it is ∼44% in SSRQs.

Abstract Copyright:

Journal keyword(s): galaxies: photometry - quasars: general - galaxies: active

Simbad objects: 40

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Number of rows : 40
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2022
#notes
1 FBQS J0001-0020 QSO 00 01 11.1962212464 -00 20 11.564753172   19.78 19.49     ~ 34 0
2 4C -00.01 QSO 00 06 22.6058589240 -00 04 24.453903468   20.14 19.35     ~ 187 1
3 LBQS 0056-0009 Sy1 00 59 05.5147782072 +00 06 51.620377428   18.07 17.89 16.9   ~ 254 1
4 FBQS J0100+0022 QSO 01 00 33.5023330440 +00 22 00.185412360   18.21 18.02     ~ 34 0
5 4C -01.06 QSO 01 08 26.8423531848 -00 37 24.164003640   18.11 17.82     ~ 113 1
6 SDSS J012401.76+003500.9 QSO 01 24 01.7641576440 +00 35 00.937932036   20.98 20.74     ~ 25 1
7 4C -00.10 QSO 01 25 17.1506405376 -00 18 28.907967636   18.73 18.60 18.4   ~ 80 1
8 QSO B0131+0058 QSO 01 33 52.6595091120 +01 13 45.274969524   18.82 18.50     ~ 48 0
9 SDSS J013514.39-000703.8 Sy1 01 35 14.3971413792 -00 07 03.749732148   20.67 20.40     ~ 19 0
10 2SLAQ J015105.80-003426.4 Sy1 01 51 05.8017636264 -00 34 26.363823708   19.48 19.17     ~ 35 0
11 [VV2006] J015509.0+011523 QSO 01 55 09.0008101056 +01 15 22.576724388   18.97 18.67     ~ 24 0
12 SDSS J015832.51-004238.1 QSO 01 58 32.5209381504 -00 42 38.246092848   19.45 19.34     ~ 27 1
13 2MASS J02023433+0003015 QSO 02 02 34.3245763584 +00 03 01.799506764   18.98 18.75     ~ 27 0
14 SDSS J020326.98+003744.4 QSO 02 03 26.9818526904 +00 37 44.374313712   20.68 20.50     ~ 17 1
15 PB 6739 QSO 02 12 25.5667246680 +01 00 56.148118164   18.64 18.57     ~ 42 1
16 [VV96] J021612.3-010519 QSO 02 16 12.2121383016 -01 05 18.824942904   18.35 18.06 18.12   ~ 57 0
17 [VV2006] J021728.6-005227 QSO 02 17 28.6363613880 -00 52 27.210228132   20.36 20.08     ~ 32 1
18 QSO B0222+000 BLL 02 25 08.0769697320 +00 17 07.254982680   18.93 18.59     ~ 47 1
19 [VV2006] J023313.8-001215 QSO 02 33 13.8173046336 -00 12 15.352489296   19.73 19.51     ~ 29 0
20 4C 00.09 QSO 02 45 34.0700249280 +01 08 13.738724124   19.84 19.26     ~ 46 0
21 [VV2006] J024854.8+001055 QSO 02 48 54.8046520728 +00 10 53.884100676   19.72 19.32     ~ 27 1
22 LBQS 0256-0031 BLL 02 59 28.5159902664 -00 19 59.976263532   17.74 17.58 17   ~ 126 0
23 [VV2006] J031318.7+003623 QSO 03 13 18.6667466136 +00 36 23.906904660   19.03 18.60     ~ 33 0
24 3C 111 Sy1 04 18 21.2772425736 +38 01 35.801359968   19.75 18.05     ~ 901 1
25 Mrk 1506 Sy1 04 33 11.0956735296 +05 21 15.619461552   15.72 15.05 10.08   ~ 1927 2
26 3C 273 BLL 12 29 06.6998257176 +02 03 08.597629980   13.05 14.830 14.11   ~ 5584 1
27 3C 279 Bla 12 56 11.1663795384 -05 47 21.528432492   18.01 17.75 15.87   ~ 2888 2
28 QSO J1512-0906 Bla 15 12 50.5330369584 -09 05 59.830296360   16.74 16.54     ~ 1236 1
29 [VV2006] J213004.7-010244 QSO 21 30 04.7595001992 -01 02 44.428962948   18.37 18.11     ~ 31 0
30 4C -00.78 QSO 21 35 13.1040843528 -00 52 43.861439208   18.44 18.20     ~ 40 1
31 CLASS J220719.7826+004157.304 QSO 22 07 19.7765433168 +00 41 57.311183904   20.01 19.79 20.3   ~ 35 1
32 FIRST J221410.0+005228 QSO 22 14 09.9681702744 +00 52 27.028986312   18.4 19.12 18.2   ~ 29 0
33 BWE 2224-0009 QSO 22 27 29.0601479472 +00 05 21.966887148   19.67 19.28     ~ 31 1
34 3C 454.3 Bla 22 53 57.7480438728 +16 08 53.561508864   16.57 16.10 15.22   ~ 2690 2
35 FBQS J2316+0100 QSO 23 16 07.2531728808 +01 00 12.906539064   19.06 18.75     ~ 37 0
36 SDSS J233200.01+011510.9 QSO 23 32 00.0152826768 +01 15 10.904648220   20.50 20.24     ~ 18 1
37 [VV2000] J233624.1+000246 QSO 23 36 24.0477013440 +00 02 45.967756056   18.36 18.05     ~ 39 1
38 SDSS J234624.56+001914.2 QSO 23 46 24.5602891176 +00 19 14.163215628   19.81 19.63     ~ 19 1
39 QSO B2345+008 QSO 23 48 30.9833830608 +01 10 37.657922988   21.05 20.81     ~ 19 0
40 4C -01.61 BLL 23 51 56.1224889360 -01 09 13.315371768   16.83 16.59     ~ 334 1

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2022.08.08-04:12:53

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