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Astronomy Reports, Vol. 49, No. 5, 2005, pp. 374­389. Translated from Astronomicheski Zhurnal, Vol. 82, No. 5, 2005, pp. 420­436. i Original Russian Text Copyright c 2005 by Afanas'ev, Dodonov, Moiseev, Gorshkov, Konnikova, Mingaliev.

Spectral Studies with the Special Astrophysical Observatory 6 m and RATAN-600 Telescopes
V. L. Afanas'ev1 , S. N. Dodonov1 , A. V. Moiseev1 , A. G. Gorshkov2 , V. K. Konnikova2 , and M. G. Mingaliev
1

1

Special Astrophysical Observatory, Russian Academy of Sciences, Nizhni i Arkhyz, Karacha i-Cherkessian Republic, 357147 Russia 2 Sternberg Astronomical Institute, Universitetski i pr. 13, Moscow, 119899 Russia
Received September 17, 2004; in final form, December 3, 2004

Abstract--We present optical identifications, classifications, and radio spectra for 19 radio sources from a complete sample in flux density with declinations 10 -12 30 (J2000) obtained with the 6-m optical ° telescope (4000­9000 A) and RATAN-600 radio telescope (0.97­21.7 GHz) of the Special Astrophysical Observatory. Twelve objects with redshifts from 0.573 to 2.694 have been classified as quasars, and two objects with featureless spectra as BL Lac objects. Four objects are emission-line radio galaxies with redshifts from 0.204 to 0.311 (one also displaying absorption lines), and one object is an absorption-line galaxy with a redshift of 0.214. Radio flux densities have been obtained at six frequencies for all the sources except for two extended objects. The radio spectra of five of the sources can be separated into extended and compact components. Three objects display substantial rapid (on time scales from several days to several weeks) and long-term variability of their flux densities. c 2005 Pleiades Publishing, Inc.

1. INTRODUCTION We present optical and radio spectra for nineteen radio sources from a complete sample in flux density having declinations 10 -12 30 (J2000), right ascensions 0­24h , and |b| > 15 . The sample was selected from the GB6 catalog [1] and contains 153 sources with flux densities above 200 mJy at 4.85 GHz [2]. We have identifications with optical objects down to 21m for 86% of the sources with flat spectra, (3.9-7.7) > -0.5 (S ), and 60% of the sources with steep spectra (3.9-7.7) < -0.5. It is necessary to obtain the redshifts of the sample sources in preparation for constructing the corresponding quasar luminosity function. Including our new results presented here, 88% of all identified sample sources have now been classified. A substantial number of the objects had been classified earlier [3]; our own previous classifications are presented in [4, 5]. The sample has been monitored in the radio since 2000. 2. RADIO AND OPTICAL OBSERVATIONS Optical spectra of all the objects were obtained with the 6-m telescope of the Special Astrophysical Observatory (SAO) of the Russian Academy of Sciences in 2001­2002. We used the multipurpose SCORPIO spectrograph [6] in its long-slit mode

with a TK1024 CCD detector (1024â1024 pixels, readout noise 3 el.). The spectral range of the spec° trograph is 3800 to 9200 A, with the dispersion being ° approximately 6 A/pixel. The effective instrumental ° resolution was roughly 20 A. The spectra were processed in the standard way using software developed in the Laboratory for Spectroscopy and Photometry of the SAO. The radio observations were carried out with the RATAN-600 telescope. Seven sources were observed as part of a monitoring program to study fluxdensity variability on time scales of several days to several weeks. These sources were observed daily using the North sector of the RATAN-600 during September 6­November 26, 2000 (82 days), June 5­September 10, 2001 (98 days), and June 19­ September 23, 2002 (97 days). The radio flux densities of the other sources were obtained during May 31­June 4, 2001, October 31­ November 19, 2001, and June 6­10, 2002 on the North sector and during October 31­November 19, 2003 on the South sector, using the flat reflector. The 2000 and 2001 observations were carried out at 0.97, 2.3, 3.9, 7.7, 11.1, and 21.7 GHz, while 0.97 GHz was excluded from the 2002 and 2003 observations. The parameters of the detectors and beams are given in [7]. A beam-modulation regime was employed at 7.7, 11.1, and 21.7 GHz.

1063-7729/05/4905-0374$26.00 c 2005 Pleiades Publishing, Inc.


SPECTRAL STUDIES WITH THE SAO 6 M AND RATAN-600 TELESCOPES Table 1. Coordinates of the objects Radio coordinates (J2000) RA 01h 43m 31.093 02 42 29.171 03 15 21.039 04 44 12.467 04 48 50.413 04 49 07.672 05 09 27.457 05 16 46.646 07 49 27.385 07 58 07.658 09 14 19.360 13 27 54.707 14 53 44.241 15 22 12.151 16 27 37.032 17 22 44.582 17 28 07.051 23 12 10.467 23 15 34.250
s

375

Optical­radio RA -0.013 -0.006 0.081 0.010 -0.001 -0.029 -0.001 -0.016 0.002 0.072 0.166 -0.010 0.003 0.085 -0.003 -0.005 0.007 -0.031 0.095
s

R 19.75 19.55 18.69 18.50 19.08 18.38 18.53 17.96 18.87 15.95 18.65 19.44 19.49 18.01 18.89

B 20.55 19.89 19.00 20.01 20.46 19.18 19.13 19.59 16.29 20.88 19.78 20.78 19.04 20.94 20.88

DEC 12 15 42.95 11 01 00.72 10 12 43.12 10 42 47.29 11 27 54.39 11 21 28.63 10 11 44.59 10 57 54.77 10 57 33.12 11 36 46.05 10 06 38.28 12 23 08.71 10 25 57.57 10 41 30.35 12 16 07.11 10 13 35.77 12 15 39.48 12 24 03.46 10 27 18.57

DEC 0.07 0.57 0.09 -0.03 0.21 0.14 0.08 0.23 0.16 1.80 2.45 1.09 -0.40 -0.35 0.07 0.26 0.55 -0.64 0.05 18.90 16.92

Reference to survey JVAS JVAS NVSS JVAS JVAS JVAS JVAS JVAS JVAS JVAS NVSS NVSS JVAS NVSS JVAS JVAS JVAS NVSS TEXAS

19.10 19.27

The processing of the radio data is described in [2, 8]. The calibration was carried out using observations of J1347+1217, whose angular size is substantially smaller than the horizontal crosssection of the beams at all the frequencies observed. We adopted flux densities of 6.15, 4.12, 3.23, 2.36, 1.99, and 1.46 Jy at 0.97, 2.3, 3.9, 7.7, 11.1, and 21.7 GHz, respectively, for this source. 3. RADIO AND OPTICAL COORDINATES Columns 1 and 2 of Table 1 present the J2000 coordinates of the studied objects taken from the Jodrell Bank­VLA Astrometric Survey (JVAS) catalog at 8.4 GHz [9] or the NRAO VLA Sky Survey (NVSS) catalog at 1.4 GHz [10]. The rms errors of the JVAS coordinates are 0.014 , while the rms errors for the NVSS coordinates are typically 0.5 . The object J2315+1027 is a double source in the NVSS; the optical object is situated at the position corresponding to the weighted average of the coordinates of the two
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radio sources, close to the coordinates given in the Texas Survey at 0.365 GHz [11]. Columns 3 and 4 contain the differences between the optical coordinates from the USNO astrometric survey [12] and the radio coordinates. Columns 5 and 6 present the USNO R and B magnitudes, and column 7 gives references for the coordinates. The object J0914+1006 is a double or triple source with a total extent of no less than 30 , and the difference between its optical and NVSS coordinates is substantial. 4. RESULTS Figures 1­4 present the optical spectra of the objects, Figs. 5, 6 the radio spectra, and Table 2 data from the optical observations. The columns present (1) the name of the object, (2) the spectral lines observed, (3) their wavelengths in the rest frame of the source and as observed, (4) the redshift, (5) the spectral class, (6) the date of the observations, and (7) the exposure time in minutes. Lines marked with


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AFANAS'EV et al.

2.0 1.5 1.0 0.5 0 ­ 0.5 ­ 1.0 4 2 0 ­2 ­4 Flux, 10­16 erg/cm2 s å 0.6 0.4 [OII] 0.2 [OIII] 4000 5000 Ly CIV 4000 5000 6000 MgII

()

x 0143 + 1215 z = 1.180

7000 (b) CIII]

8000

9000

0242 + 1101 z = 2.694 6000 7000 (c) 8000 H 9000 [SII] 10 000

x 0 ­ 0.2 4 3 2 1 0 ­1 ­2 0.4 CIII] 0.3 0.2 0.1 0 4000 5000 0448 + 1127 z = 1.375 x 6000 7000 Wavelength, å 8000 9000 4000 5000 SiIV 0444 + 1042 z = 2.403 6000 7000 (e) MgII 8000 9000 Ly CIV CIII] 4000 5000 0315 + 1012 z = 0.222 6000 7000 (d) 8000 9000

Fig. 1. Optical spectra of the radio sources J0143+1215, J0242+1101, J0315+1012, J0444+1042, and J0448+1127 obtained using the SAO 6 m telescope.

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1.0 0.8 0.6 0.4 0.2 0 ­0.2 2 1 0 ­1 ­2 ­3 Flux, 10­16 erg/cm2 s å 0.4 0.3 0.2 0.1 0 ­ 0.1 1.2 1.0 0.8 0.6 0.4 0.2 0 1.0 0.8 0.6 0.4 0.2 0 4000 5000 6000 7000 Wavelength, å 8000 9000 10 000 H H MgII (e) 0758 + 1136 z = 0.573 0749 + 1057 z = 0.214 4000 5000 6000 7000 ÊaI MgI (d) x H x 0516 + 1057 z = 1.580 4000 5000 6000 7000 8000 9000 x CIV ÊIII] HeII 0509 + 1011 4000 5000 6000 7000 (c) 8000 9000 (b) 4000 5000 6000 7000 8000 9000 x 0449 + 1121 ()

8000

9000

10 000

Fig. 2. Same as Fig. 1 for J0449+1121, J0509+1011, J0516+1057, J0749+1057, and J0758+1136.

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0.8 0.6 0.4 0.2 0 3.0 2.5 2.0 1.5 1.0 0.5 0 Flux, 10­16 erg/cm2 s å 0.5 0.4 0.3 0.2 0.1 0 0.8 0.6 0.4 0.2 0 0.6 CIII] 0.4 0.2 0 ­ 0.2 1627 + 1216 z = 1.216 4000 5000 6000 7000 Wavelength, å 8000 9000 10 000 MgII (e) [NeV] [OII] 4000 5000 6000 7000 1522 + 1041 z = 0.204 [OII] [OIII] (d) x 4000 5000 6000 7000 8000 H [SII] H MgI NaI x 8000 9000 10 000 9000 10 000 CIV 1453 + 1025 z = 1.770 CIII] (c) 4000 1327 + 1223 z = 0.950 5000 6000 7000 J x 8000 9000 10 000 [NeIV] MgII 4000 [OII] x 5000 6000 7000 (b) [OII] [NeV] 8000 9000 [OIII] 10 000 0914 + 1006 z = 0.311 [OIII] () H

MgII

Fig. 3. Same as Fig. 1 for J0914+1006, J1327+1223, J1453+1025, J1522+1041, and J1627+1216.

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0.4 0.3 0.2 0.1 MgII [NeV]

()

1722 + 1013 z = 0.732

x 0 2.0 1.5 1.0 Flux, 10­16 erg/cm2 s å 0.5 x 0 0.4 0.2 0 2312 + 1224 z = 1.285 4000 5000 6000 [OIII] H x 4000 5000 6000 7000 Wavelength, å 8000 9000 10 000 7000 (d) H [SII] 8000 9000 10 000 ÊIII] 4000 5000 6000 7000 MgII (c) 8000 9000 10 000 MgII (b) H 1728 + 1215 z = 0.589 [OIII] 4000 5000 6000 7000 8000 9000 10 000

­ 0.2 ­ 0.4 ­ 0.6 1.0 0.8 0.6 0.4 0.2 0 ­ 0.2 [OII] 2315 + 1027 z = 0.255

Fig. 4. Same as Fig. 1 for J1722+1013, J1728+1215, J2312+1224, and J2315+1027.

asterisks were observed in absorption, and the remaining lines in emission. Table 3 contains the radio flux densities of the sources averaged over the observations, and presents the name of the object, the flux densities at 0.97, 2.3, 3.9, 7.7, 11.1, and 21.7 GHz in mJy and their rms errors, and the dates to which the flux densities correspond. Observational data for variable sources are presented for multiple epochs. Below, we discuss the optical spectrum and object
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classification of each object, together with the parameters of the radio spectrum. When a non-power-law spectrum was observed, we attempted to separate it into an extended component with a power-law spectrum, S = So , and a compact component whose spectrum could be represented by a logarithmic parabola, log S = So + B log + C log2 . The method used to separate the two components in the spectra is described in detail in [2]. This procedure also took into account the 365 MHz (Texas Survey) and 1400 MHz (NVSS) flux densities.


380
1000 100 10 1 10 000 ()

AFANAS'EV et al.
2000 1000 (b)

300 0143 + 1215 100 1000 (c) 0315 + 1012 400 (d) 0242 + 1101

1000

0444 + 1042 100 1000 Flux density, mJy (e) 100 10 000 (f )

100 0448 + 1127 10

1000 0449 + 1121 100 (g) 10 000 (h) 0516 + 1057

1000

400

1000 0509 + 1011

100 1000 100 (i)

100 1000 (j)

100 10 0749 + 1057 1 1 10 3 Frequency, GHz 30 10 0758 + 1136 1 10 3 Frequency, GHz 30

Fig. 5. Radio spectra of J0143+1215, J0242+1101, J0315+1012, J0444+1042, J0448+1127, J0449+1121, J0509+1011, J0516+1057, J0749+1057, and J0758+1136.

If the flux density of a radio source varied either from one set of observations to another or within a single set of observations, we present the parameters of the variations. For some of the sources, the relative variability amplitude is given, V = (Smax - Smin )/(Smax + Smin ). For sources with variability time scales shorter than a month, we present the modulation index m, which is defined as the ratio of the

standard deviation of the variable component and the average flux density in percent.

4.1. J0143+1215
A single broad emission line is seen in the optical ° spectrum (Fig. 1a), interpreted as MgII 2798 A at a redshift of z = 1.18. We classify this object as a
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1000 () 1000 (b)

381

100

100

1327 + 1223 10 1000 10 (c) 1000

1453 + 1025

(d)

400 100

1522 + 1041 Flux density, mJy 10 1000 100 2000 1000 400 400 1722 + 1013 100 1000 100 (g)

1627 + 1216

(e)

(f )

1728 + 1215 1 3 10 Frequency, GHz 30

100

2312 + 1224 10 1 3 10 Frequency, GHz 30

Fig. 6. Same as Fig. 5 for J1327+1223, J1453+1025, J1522+1041, J1627+1216, J1722+1013, J1728+1215, and J2312+1224.

quasar. Quasars with redshifts z 1 usually display ° strong CIII] 1909 A emission; here, however, this line is located in a noisy part of the spectrum and is not visible. We obtained radio observations of this source in 2000, 2001, and 2002. The flux densities at all frequencies remained constant within 3 . The spectrum falls off with frequency, flattening at high frequencies. We were able to fit two components in the spectrum. The extended component is best fitby the power
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law S = 350 -0.65 starting from 0.365 GHz. The compact component is best fit by the logarithmic parabola log S = 1.069 + 0.982 log - 0.322 log 2 . The compact component is optically thick in our frequency range; the maximum flux density (Smax = 65 mJy) is near 35 GHz. The extended component dominates the radiation at 0.97­7.7 GHz, the flux densities of the extended and compact components are comparable at 13 GHz, and the radiation of the compact component begins to dominate at higher frequencies. The observed spectrum is indicated by the


382 Table 2. Optical data Object J0143+1215 J0242+1101 Spectral lines MgII Ly CIV CIII] J0315+1012 [OII] H [SII] J0444+1042 Ly SiIV CIV CIII] J0448+1127 J0449+1121 J0509+1011 J0516+1057 CIV HeII CIII] J0749+1057 CaI* MgI* H* J0758+1136 MgII H H J0914+1006 [OII] [OIII] H J1327+1223 [NeIV] MgII [NeV] [NeV] [OII] [OIII] [OIII] J1453+1025 CIV CIII] MgII 1549/4000 1640/4215 1909/4920 4227/5130 5175/6280 6563/7970 2798/4400 4102/6435 4340/6825 3727/4890 5007/6560 6563/8605 2424/4725 2798/5460 3346/6525 3426/6680 3727/7270 4958/9670 5007/9760 1549/4295 1909/5290 2798/7760 CIII] MgII

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° Wavelength, A 2798/6100 1216/4490 1549/5720 1909/7055 3727/4550 6563/8020 6717/8210 1216/4140 1403/4760 1549/5265 1909/6500 1909/4530 2798/6650

z 1.180 2.694

Spectral type QSO QSO

Date 16.09.01 18.10.01

Exposure time, min 20 10

0.222

Em. G

16.09.01

20

2.403

QSO

16.09.01

16.7

1.375

QSO Lac Lac

15.10.01 21.09.01 18.10.01 15.10.01

20 10 10 10

1.580

QSO

0.214

Abs.G

15.10.01

20

0.569

QSO

06.02.02

6

0.311

Em.G

06.02.02

10

0.950

QSO

12.05.02

10

1.773

QSO

08.02.02

20

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SPECTRAL STUDIES WITH THE SAO 6 M AND RATAN-600 TELESCOPES Table 2. (Contd.) Object J1522+1041 Spectral lines [OII] H * [OIII] [OIII] MgI* NaI* H [SII] J1627+1216 CIII] MgII [NeV] [OII] J1722+1013 J1728+1215 MgII [NeV] MgII H [OIII] J2312+1224 J2315+1027 CIII] MgII [OII] H [OIII] [OIII] H [SII] ° Wavelength, A 3727/4485 4861/5850 4958/5970 5007/6030 5175/6230 5893 /7095 6563/7903 6724/8095 1909/4228 2798/6200 3426/7592 3727/8260 2798/4845 3426/5935 2798/4446 4861/7725 5006/7955 1909/4360 2798/6400 3727/4680 4861/6100 4958/6220 5007/6285 6563/8240 6717/8430 0.255 Em.G 20.09.01 20 1.285 QSO 18.10.01 10 0.589 QSO 04.06.02 20 0.732 QSO 11.05.02 10 1.216 QSO 11.05.02 10 z 0.204 Spectral type Em.G Date 12.05.02

383

Exposure time, min 10

filled circles in Fig. 5a, with the sizes corresponding to the observational errors. The spectra of the extended and compact components are marked by the solid and dashed curves, respectively.

4.2. J0242+1101
We were able to identify three emission lines in the ° ° optical spectrum (Fig. 1b): Ly 1216 A, CIV 1549 A, ° and CIII] 1909 A. The redshift derived from these lines is 2.694. The object is a quasar. The Ly line is usually stronger in radio quasars; the object may be a broad-absorption-line (BAL) quasar, with absorption in the vicinity of the nucleus partially weakening the
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line emission. This is also suggested by the asymmetry of the Ly and CIV lines. Radio observations were obtained four times in 2000­2003. All of the spectra display a minimum in the range from 3 GHz (2002) to 7.5 GHz (2000). The largest flux-density variation was detected at 21.7 GHz, from 1157 ± 15 in October 2000 to 1735 ± 20 in August 2002. We were able to fit two components in the observed spectra. The strong extended component is best fit by the power law S = 1930 -0.89 at 2.3­21.7 GHz; the parameters of this spectrum remained essentially constant at all observing epochs. The spectrum becomes self-absorbed at lower frequencies, with the


384 Table 3. Radio data Object 0.97 GHz J0143+1215 J0242+1101 348 1737 1660 10 35 28 2.3 GHz 220 1383 1340 1380 1372 J0315+1012 J0444+1042 J0448+1127 J0449+1121 2180 820 92 430 687 25 32 15 30 18 1120 596 178 1070 1285 1603 6871 J0509+1011 676 682 394 J0516+1057 J0749+1057 J0758+1136 J0914+1006 J1327+1223 J1453+1025 J1522+1041 J1627+1216 J1722+1013 348 360 360 J1728+1215 30 30 25 22 19 18 11 52 20 25 30 30 30 15 695 558 205 982 1330 940 1007 219 557 420 560 180 393 260 420 399 383 359 353 320 294 384 378 339 257 250 394 403 316 210 J2312+1224 700 25 370 06 17 08 10 40 20 18 15 15 10 11 38 16 10 20 26 12 30 15 20 23 15 45 07 07 14 13 12 18 30 16 07 24 29 15

AFANAS'EV et al.

Flux density with its error, mJy 3.9 GHz 175 1202 1170 1301 1201 725 500 230 1324 1739 2035 1898 662 464 418 650 820 877 182 346 03 07 04 04 10 08 13 11 19 99 19 13 08 04 14 05 05 07 04 05 09 15 04 03 10 07 07 07 06 04 06 06 15 11 370 374 716 613 517 470 152 06 06 09 07 10 13 05 1461 2671 2463 1595 598 437 467 401 652 578 169 298 97 20 18 13 05 05 17 08 04 06 09 07 10 10 04 03 06 11 7.7 GHz 136 1082 1167 1380 1106 491 377 04 09 06 07 09 09 05 11.1 GHz 128 1144 1265 1507 1185 427 340 280 1654 3236 2807 2324 597 488 697 980 587 481 165 294 02 06 05 10 10 14 08 11 78 25 72 13 01 01 08 08 04 12 11 07 08 14 03 03 17 07 07 12 07 14 10 20 14 07 220 730 351 435 960 793 571 584 67 20 48 34 32 22 20 45 40 09 21.7 GHz 110 1157 1378 1735 1270 350 250 260 1788 4429 3130 2782 547 661 560 646 490 370 126 250 10 15 22 20 50 45 30 20 08 34 30 61 15 21 35 08 12 35 15 20 20 40 13 14

Epoch 23.07.2001 16.10.2000 23.07.2001 06.08.2002 12.09.2003 15.11.2001 15.11.2001 04.11.2001 16.10.8000 03.07.2001 16.08.7001 12.09.2073 16.10.2000 23.02.2001 15.11.2001 12.09.2003 23.07.2001 12.09.2003 04.11.2001 04.11.2001 02.06.2001 02.06.2001 06.09.2003 23.07.2001 06.08.2002 08.06.2002 15.11.2001 02.06.2001 04.11.2001 12.09.2003 16.10.2000 23.07.2001 08.06.2002 12.09.2003 04.11.2001

411 254 293 321 205 275 385 374 340 537 524 429 350 265

405 285 194 230 112 259

409 314 160 198 85 252 567 369 395 849 737 578 565 115

415 403 116 184

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turnover frequency being near 0.7 GHz and the flux density at the turnover being Smax 1600 mJy. The extended component is plotted by the solid curve in Fig. 5b. The filled circles mark the spectrum obtained in July 2001. In each of the four sets of observations, the spectrum of the compact component is best fit by the logarithmic parabola derived from the data averaged over the entire period of observations for this source. These spectra are plotted by the dashed and dash­ dotted curves in Fig. 5b. The spectrum of the compact component rises toward higher frequencies, with its maximum being above 40 GHz. This component is optically thick at the frequencies of our observations. The 21.7 GHz flux density reached a minimum in 2000, increased in 2001­2002, and then decreased again in 2003 to nearly its level in 2000. These flux-density variations cannot be explained as the development of a single isolated outburst. In the standard model for the variability [13, 14], the flux density at a certain frequency should decrease only due to the transition to the optically thin part of the spectrum, which does not occur in this case. It may be that we are observing multiple outbursts whose evolution time scales are shorter than the duration of our observations. The observed evolution of the compact component is then the result of a kind of stroboscopic effect, due to our undersampling of the variations. The flux density also varied within each set of observations. The largest variations were observed during the 97 nightly observations in 2002: the 11.1 GHz flux density increased from 1370 mJy at the beginning of this series to 1600 mJy at the end, while the 21.7 GHz flux density varied from 1400 to 1820 mJy. On June 30, 2002, the spectrum of the compact component was best fit by the parabola log S = 2.300 + 1.104 log - 0.360 log 2 , which has its maximum at max 35 GHz. Twenty days later, this spectrum was best fit by the parabola log S = 2.382 + 0.938 log - 0.247 log 2 , whose maximum is at 80 GHz. Such spectral behavior provides evidence that we are observing the evolution of two outbursts. The first was observed on June 30, 2000, while the second was observed 20 days later, at an earlier stage in its evolution. Both outbursts are well fit by logarithmic parabolas, which suggests that only one of the outbursts dominates at each these epochs. Thus, the first outburst evolved sufficiently over 20 days that its contribution to the spectrum had become negligible by the later epoch. The object displays a high radio luminosity, close to the maximum observed for all the sources in the complete sample: L =11.1 GHz = 13 â 1034 erg/s Hz.
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This luminosity is calculated for a homogeneous isotropic cosmological model with zero cosmological constant, deceleration parameter q = 0.5, and H = 65 km s-1 Mpc-1 .

4.3. J0315+1012 We identified four weak emission lines with redshift z = 0.222 in the optical spectrum (Fig. 1c): [OII] ° ° ° 3727 A, the [OIII] 4958, 5006 A doublet, H 6563 A, ° . The object has been classified as an and [SII] 6717 A emission-line galaxy. The spectrum is a power law, S = 2055 -0.723 mJy, at 0.178­3.9 GHz. Above 3.9 GHz, the spectrum flattens due to the appearance of a compact component (Fig. 5c), however, we were not able to obtain a good two-component fit to the spectrum. 4.4. J0444+1042 Four emission lines are observed in the optical spectrum (Fig. 1d), which we identified as Ly ° ° ° 1216 A, CIV 1549 A, and weak SiIV 1403 A and ° at a redshift of z = 2.403. The object CIII] 1909 A has been classified as a quasar. As for J0242+1101, the Ly line is weaker than is typical for radio quasars, however, the line maximum may be distorted by noise. The spectrum for November 2001 can be fitby the power law S = 815 -0.372 mJy at 0.97­21.7 GHz (Fig. 5d). The spectrum is flat ( > -0.5); no flux variability is observed. 4.5. J0448+1127 ° ° We identified CIII] 1909 A and MgII 2798 A in the optical spectrum (Fig. 1e). The full width at half ° maximum (FWHM) of both lines is 45 A in the rest frame of the source. The redshift indicated by these lines is z = 1.375; the object is a quasar. We obtained radio observations in 2001 and 2002. No flux-density variations were seen within the errors. The extended component is absent or too weak to be detected. The spectrum of the compact component averaged over the two sets of observations is best fit by the logarithmic parabola log S = 1.979 + 0.902 log - 0.432 log 2 , which has its maximum near 10 GHz and a peak flux density of 280 mJy (Fig. 5e). We were not able to measure the flux density at 7.7 GHz, because the angular distance to the adjacent strong source J0449+1121 and the distance between the feed horns of the system are very similar (the detecting equipment operates in a beammodulation regime at this frequency). The approximate flux density at 7.7 GHz is 274 mJy.


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4.6. J0449+1121 No lines are visible in the optical spectrum, and we accordingly classified this source as a BL Lac (Fig. 2a). We obtained radio observations in 2000­2003. Figure 5f presents the spectra obtained (the spectrum for October 2000 is shown by the dash­dotted curve, for July 2001 by the dashed curve, and for July 2002 by the solid curve). Note the strong long-term variability of the flux density (Table 3), which is accompanied by spectral variations. The spectral maximum was at 25 GHz in October 2000, but at frequencies above the observed interval at the other epochs. The minimum flux density was observed in October 2000 at all frequencies; the maximum flux density at 7.7­21.7 GHz was observed in July 2002 and the maximum at 2.3 GHz in September 2003. The relative variability amplitudes are V = 0.43, 0.33, 0.29, 0.22, and 0.28 at 21.7, 11.1, 7.7, 3.9, and 2.3 GHz, respectively. These figures represent lower limits for the relative variability amplitudes, since the observations may be subject to a "stroboscopic effect" due to the presence of long gaps in the observations. In addition to its long-term variability, the source displays strong variability on time scales shorter than a month. Analysis of the corresponding structure functions [15, 16] indicates that the characteristic time scale for variations increases with decreasing frequency. The variability time scale is four days at 11.1 GHz, with the modulation index averaged over all epochs being m = 3.5%. The characteristic time scale at 7.7 GHz is different at different epochs, and was four days (m = 2.5%), five days (m = 4.2%), and eight days (m = 4.3%) in 2000, 2001, and 2002, respectively. The characteristic time scale was substantially longer at 3.9 GHz: 22 days (m = 2.9) in 2000, 10 days (m = 4.8) in 2001, and 16 days (m = 5.0) in 2002. Flux-density variations were detected at 2.3 GHz only in 2001, when they displayed a characteristic time scale of 14 days (m = 5.0); there are appreciable gaps in the measurements at each of the other epochs due to high levels of industrial and environmental noise. We believe that this variability is due to scintillation in the interstellar medium; in this case, the frequency dependence of the characteristic time scale results from the frequency dependence for the angular size. The variations of the modulation index may be determined by variations in the degree of compactness of the source. The influence of the adjacent source J0448+1127, which lies in one of the 7.7 GHz horns of the system, is significantly smaller, since its flux density is roughly afactor of five lower.

4.7. J0509+1011 The optical spectrum does not contain any lines, leading us to classify it as a BL Lac object (Fig. 2b). Figure 5g presents the radio spectra obtained in October 2000 (solid curve) and November 2001 (dash­dotted curve) averaged over the total time spanned by the observations, together with the spectrum obtained at the end of a long series of observations in 2001, averaged over 10 days (dashed curve). The spectrum varied during June 5­September 10, 2001, and there is no single parabolic fit that is suitable for the entire averaged dataset. Like J0449+1121, this source displays strong long-term variability of its flux density (Table 3). The shape of the spectrum also varies markedly. For example, in 2000, the spectrum could be fit well by a parabola with its maximum near 1 GHz, while the July 2001 spectrum has a minimum at 5 GHz, and the November 2001 spectrum a minimum below 1 GHz. The flux-density variations are particularly large at 0.97, 2.3, and 3.9 GHz, where the relative amplitudes of the variability are V = 0.27 (October 2000, November 2001), 0.29 (October 2000, September 2003), and 0.22 (October 2000, November 2001). The dates in parentheses indicate the epochs of maximum and minimum flux density. Since no 0.97 GHz data are available after November 2001, the real relative variability amplitude at this frequency may be even higher. It is likely that we are undersampling the variability, and that the real variability time scale does not exceed several months. This hypothesis is supported by the 21.7 GHz flux-density variations in 2001. The flux density was initially 512 ± 15 mJy, but had increased to 700 ± 20 mJy 98 days later. The source also displays short-timescale variability. The structure functions derived from the 2000 and 2001 observations yield a characteristic time scale of three to four days. In 2000, the modulation index was m = 4.3, 7.4, and 10.0%,respectively, at7.7,3.9,and 2.3 GHz; no variability was detected at 7.7 GHz in 2001, while the modulation index was 4.5% at both 3.9 and 2.3 GHz. 4.8. J0516+1057 We were able to identify three weak emission lines with redshift z = 1.580 in the optical spectrum ° ° ° (Fig. 2c): CIV 1549 A, HeII 1640 A and CIII] 1909 A. ° A line badly distorted by noise is visible at 7220 A, which, at this redshift, can be identified with MgII ° 2798 A. The object is classified as a quasar. We obtained radio observations in 2001 and 2003; no significant flux-density variations were detected. The 0.97­21.7 GHz radio spectrum is best fit with the power law S = 1270 -0.322 mJy (Fig. 5h).
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4.9. J0749+1042 We identified three absorption lines in the optical ° ° spectrum (Fig. 2d): CaI 4227 A, MgI 5175 A, and ° H 6563 A. The redshift derived from these lines is z = 0.214. The object is an absorption galaxy. The source was observed in the radio in June 2001 and November 2001. Its flux density did not vary during this interval. We were able to fit an extended component with a power-law spectrum starting from 0.365 GHz in the combined spectrum (Fig. 5i, filled circles): S = 167 -0.92 mJy (solid curve). The spectrum of the compact component is best fit by the parabola log S = 1.761 + 0.940 log -0.532 log 2 , which has its maximum flux density (150 mJy) at 7.6 GHz (dashed curve). The extended component contributes 75% of the total flux density at 0.97 GHz. 4.10. J0758+1136 Two objects are blended in the optical spectrum. After separating their spectra, one appears to be a star. Figure 2e presents the other spectrum, in which ° ° we have identified strong MgII 2798 A, H 4102 A, ° and H 4340 A at a redshift of z = 0.569. The oxy° gen absorption line at 7650 A is probably partially canceled out by an emission line, which may be H ° 4861 A, given the redshift of the object. The MgII line ° FWHM is 40 A in the rest frame of the source. We classified this object as a quasar. The source was observed in the radio in September 2000, June 2001, and November 2001. During this interval, the flux density remained constant within the errors. The radio spectrum falls off with frequency, flattening toward high frequencies (Fig. 5j). The spectrum (filled circles) can be divided into a power-law extended component, S = 440 -0.80 mJy (solid curve in Fig. 5j), and a compact component, log S = 2.019 + 0.646 log - 0.312 log 2 ,whichhas its maximum flux density (225 mJy) at 10 GHz (dashed curve). 4.11. J0914+1006 We have identified three lines in the optical spec° ° trum with [OII] 3727 A, [OIII] 5007 A, and H ° 6563 A (Fig. 3a). The object is classified as an emission-line galaxy with a redshift of z = 0.311. The source is resolved in right-ascension by the RATAN-600 beam at frequencies above 3 GHz, and flux densities were obtained only at 0.97 and 2.3 GHz (Table 3). According to our measured flux densities and published data for the flux densities at 0.365, 1.4, and 4.85 GHz, the spectrum is described by the power law S = 420 -0.525 mJy in the interval 0.365­ 4.85 GHz.
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4.12. J1327+1223 Seven emission lines were identified in the optical ° ° spectrum (Fig. 3b): [NeIV] 2424 A, MgII 2798 A, ° ° ° [NeV] 3346 A and [NeV] 3426 A, [OII] 3727 A, weak ° ° ° [OIII] 4958 A, strong [OIII] 5007 A, and MgI 5175 A. The object is a quasar with redshift z = 0.950. We obtained radio observations in 2001 and 2003. The source displays flux-density variability and a complex spectrum. Figure 6a presents the spectrum for 2001 (filled circles). An extended component with a power-law spectrum, S = 510 -0.70 mJy, has been fit. The extended component contributes 90% of the total flux density at 0.97 GHz. At epoch June 2, 2001, the spectrum of the compact component can be described by the parabola log S = 1.835 + 1.075 log - 0.409 log 2 , which has its maximum flux density (350 mJy) at 20 GHz (Fig. 6a, dashed curve). At epoch September 6, 2003, the spectrum of the compact component can be approximated by part of a parabola that rises toward high frequencies, with the peak being located above the studied frequency interval. It is likely that the initial phase of a new outburst was observed in 2003. 4.13. J1453+1025 Three weak lines with a redshift of z = 1.773 were identified in the optical spectrum (Fig. 3c): CIV ° ° ° 1549 A, CIII] 1909 A, and MgII 2798 A. The object is classified as a quasar. We obtained radio observations in 2001 and 2002. Figure 6b presents the radio spectra for July 2001 and August 2002. Taking into account the data at 0.365 GHz, both the spectra are consistent with a two-component model: one component had its maximum at 1 GHz and remained essentially constant over the year, while the other was variable, and can be fit with parabolas with maxima near 25 GHz in July 2001 and well above the studied interval in July 2002. 4.14. J1522+0400 Both emission and absorption lines are visible in the optical spectrum (Fig. 3d). We have identified the ° ° emission lines as [OII] 3727 A, the [OII] 4958 A, ° ° ° 5007 A doublet, H 6563 A, and [SII] 6724 A. These lines yield a redshift of z = 0.204. Based on this redshift, three weak absorption lines can be identified ° ° ° with H 4861 A, MgI 5175 A, and NaI 5893 A. The object is an emission-line galaxy. The source's radio flux density is constant. Its spectrum can be described by the power law S = 640 -0.832 mJy at 0.365­11.1 GHz (Fig. 6c).


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4.15. J1627+1216
Four emission lines were identified in the optical ° ° spectrum (Fig. 3e): CIII] 1909 A, MgII 2798 A, [NeV] ° ° 3426 A, and [OII] 3727 A lines. These lines indicate a redshift of z = 1.216. The object is a quasar. We obtained radio observations on June 2001 and November 2001; the flux density remained essentially constant at all frequencies during this time. The 0.97­21.7 GHz radio spectrum can be approximated with the power law S = 333 -0.125 mJy (Fig. 6d), but the presence of large discrepancies with the fitindicates that the spectrum is complex. We were unable to separate the spectrum into components.

4.18. J2312+1224 Two weak emission lines are observed in the optical spectrum (Fig. 4c), which we identified with CIII] ° ° 1909 A and MgII 2798 A at a redshift of z = 1.285. The object is a quasar. The source displays a power-law spectrum, S = 695 -0.745 mJy, and constant flux densities at 0.97­ 21.7 GHz (Fig. 6g). The spectrum can be described with the same power-law index in the broader interval 0.178­21.7 GHz. 4.19. J2315+1027 The strongest lines in the optical spectrum (Fig. 4d) can be identified with the [OIII] 4958, ° ° 5007 A doublet and H 6563 A. In addition, [OII] ° ° ° 3727 A, [SII] 6717 A, and weak H 4861 A are visible. The redshift derived from all these lines is z = 0.255. The object is classified as an emission-line galaxy. Since the radio source is known to be double and is not resolved by the RATAN-600, we were not able to obtain its radio parameters.
5. CONCLUSION We have classified the twelve radio sources J0143+1215 (z = 1.18), J0242+1101 (z = 2.694), J0444+1042 (z = 2.403), J0448+1127 (z = 1.375), J0516+1057 (z = 1.580), J0758+1136 (z = 0.569), J1327+1223 (z = 0.950), J1453+1025 (z = 1.773), J1627+1216 (z = 1.216), J1722+1013 (z = 0.732), J1728+1215 (z = 0.589), and J2312+1224 (z = 1.285) as quasars. Their optical spectra display the standard set of lines typical for quasars at the given ° ° ° redshifts: Ly 1216 A, CIV 1549 A, CIII] 1909 A, and ° MgII 2798 A. Weaker lines are also visible in several ° ° of the spectra: SiIV 1403 A, [NeV] 3346, 3426 A, H ° ° 4861 A and the [OIII] 4958, 5007 A doublet. We observed power-law spectra (S ) in only these twelve quasars; two of them--J0444+1042 and J0516+1057--display flat spectra, with = -0.372 and = -0.322, respectively. The source J2312+1224 displays a steep spectrum with = -0.745. The flux densities of these quasars did not vary over the course of our observations. The spectra of the other nine quasars cannot be approximated by power laws. Five of these objects display long-term variability of their flux density, while the flux densities of four objects remained constant during the interval spanned by our observations. We were able to obtain two-component fits with an extended component, log S = So + log , and a compact component, log S = So + B log +
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4.16. J1722+1013
° A strong line with a width of about 50 A is observed in the optical spectrum (Fig. 4a), which we ° identified with MgII 2798 A at a redshift of z = 0.732; ° with the same redshift is also detected. [NeV] 3426 A ° A weak line is visible at 8670 A, which corresponds ° at the given redshift. The object is to [OIII] 5007 A classified as a quasar. We obtained radio observations at three epochs in 2001 and 2003. The spectrum was flat in November 2001 (Fig. 6e, dashed curve), and increased toward high frequencies at the other epochs (Fig. 6e, June 2003; the spectrum is plotted by the solid curve). A decrease in the flux density at 21.7 GHz over five months was detected--from 730 ± 48 Jy in June 2001 to 351 ± 34 Jy in November 2001. The relative amplitude of the variability is V = 0.35.

4.17. J1728+1215
Three strong lines are observed in the optical spec° trum (Fig. 4b), which we identified with MgII 2798 A, ° and the [OIII] 4958, 5007 A doublet at a ° H 4861 A, redshift of z = 0.589. The object is a quasar. We obtained four sets of radio observations in 2000­2003. The structure functions indicate substantial variability of the flux density on a time scale of 12 days at 3.9, 7.7, and 11.1 GHz. Figure 6f presents the spectra for October 2000 and September 2003. In the first spectrum (solid curve), the maximum lies substantially above the studied interval (max 110 GHz); in the second (dashed curve), the maximum is at max 20 GHz. The spectra obtained in 2001 and 2002 are between these two. It appears that we observed the development of a single outburst, with the flux-density maximum being shifted toward low frequencies with time.


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C log2 , for the spectra of the four quasars J0143+1215, J0242+1101, J0758+1136, and J1327+1223. No lines are visible in the spectra of J0449+1121 and J0509+1011, leading us to classify them as BL Lac objects. Both display substantial long-term variability with relative variability amplitudes V = 0.2­0.4. In addition, both sources display appreciable variability on shorter time scales of 3­4 days for J0509+1011 and 4­20 days for J0449+1121. In the latter source, the variability time scale depends on the frequency and observing epoch. The four objects J0315+1012 (z = 0.222), J0914+1006 (z = 0.311), J1522+1041 (z = 0.204), and J2315+1027 (z = 0.255) are emission-line ° ° galaxies. The [OII] 3727 A, [OIII] 4958, 5007 A, and ° H 4861 A lines typical of emission-line galaxies are visible in all their spectra. In J1522+1041, three absorption lines with the same redshift are also seen. The radio spectra of three of these objects are power laws; the spectrum of J0315+1012 is also a power law at 0.178­3.9 GHz, but flattens at lower frequencies, possibly reflecting the presence of weak compact components. The source J0749+1057 was identified with an absorption-line galaxy at a redshift of z = 0.214. The spectrum can be separated into an extended and compact component, with the radiation of the compact component dominating at 2.3­21.7 GHz. We have identified a number of other radio sources with absorption-line galaxies earlier; for example, J1306+1113 [5] and J2330+1218 [4]. ACKNOWLEDGMENTS This work was supported by the Federal Science and Technology Program "Astronomy," the Russian Foundation for Basic Research (project

no. 02-07-90247), and the Federal Science and Technology Project "Universities of Russia" (project no. UR 02.03.029). REFERENCES
1. P. C. Gregory, W. K. Scott, K. Douglas, and J. J. Condon, Astrophys. J., Suppl. Ser. 103, 427 (1996). 2. A. G. Gorshkov, V. K. Konnikova, and M. G. Mingaliev, Astron. Zh. 80, 978 (2003) [Astron. Rep. 47, 903 (2003)]. 3. M. P. Veron-Cetty and P. Veron, Astron. Astrophys. 374, 92 (2001). 4. V. Chavushyan, R. Mujica, J. R. Valdez, et al., Astron. Zh. 79, 771 (2002) [Astron. Rep. 46, 697 (2002)]. 5. V. L. Afanas'ev, S. N. Dodonov, A. V. Moiseev, et al., Pis'ma Astron. Zh. 29, 626 (2003) [Astron. Lett. 29, 579 (2003)]. 6. http://www.sao.ru/moisav/scorpio/scorpio.html. 7. A. M. Botashev, A. G. Gorshkov, V. K. Konnikova, and M. G. Mingaliev, Astron. Zh. 76, 723 (1999) [Astron. Rep. 43, 631 (1999)]. 8. A. G. Gorshkov and O. I. Khromov, Astrofiz. Issled., Izv. Spets. Astrofiz. Obs. 14, 15 (1981). 9. I. W. A. Browne, Mon. Not. R. Astron. Soc. 293, 257 (1998). 10. J. J. Condon, W. D. Cotton, E. W. Greisen, et al., Astron. J. 115, 1693 (1998). 11. J. N. Douglas, Astron. J. 111, 1945 (1996). 12. D. Monet, A. Bird, B. Canzian, et al.,USNO-SA1.0 (US Naval Observatory, Washington DC, 1996). 13. A. P. Marscher and W. K. Gear, Astrophys. J. 298, 114 (1985). 14. E. Valtaoja, H. Terasranta, S. Urpo, et al., Astron. Astrophys. 254, 71 (1992). 15. J. H. Simmonetti, J. M. Cordes, and D. S. Heeschen, Astrophys. J. 296, 46 (1985). 16. P. A. Hughes, H. D. Aller, and V. F. Aller, Astrophys. J. 396, 469 (1992).

Translated by K. Maslennikov

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