9270 . THE ASTRONOMICAL JOURNAL VOLUME 90, NUMBER 6 JUNE 1985 90 VLA OBSERVATIONS OF 57 SOURCES IN CLUSTERS OF GALAXIES Christopher P. O’Dea National Radio Astronomy Observatory,a) Charlottesville, Virginia 22903 1985AJ Frazer N. Owen National Radio Astronomy Observatory, Socorro, New Mexico 87801 Received 20 September 1984; revised 10 January 1985 ABSTRACT VLA observations of 57 radio sources in the directions of clusters of galaxies are presented. The data include observations of 41 narrow-angle-tail (NAT) sources, nine wide-angle-tail (WAT) sources and seven sources with complex morphology. Twin-jet structure is found in ~75% of the NATs. These observations increase the number of NATs for which there are high-sensitivity (root-mean-square noise —0.1 mJy beam-1), high-resolution ( — T') maps by about a factor of 10. Contour plots of the sources are presented. Optical finding charts for 25 previously unidentified sources are given. Brief comments on the properties of the individual radio sources are made. Finally, the general characteristics and interesting features of the different subgroups of sources are summarized. I. INTRODUCTION searched for radio emission with flux densities >0.1 Jy at 1.4 The interaction of cluster radio sources with the intraclus- GHz located within 0.5 corrected Abell cluster radii of an ter medium may determine many of the observed properties Abell cluster center (Owen et al. 1982). A total of 485 radio of these sources (e.g., De Young 1976; Burns 1979; Miley sources in the directions of 442 Abell clusters were found. 1980). Radio sources with bent or otherwise distorted struc- The single-dish survey has been followed by VLA snapshot ture are preferentially found in clusters of galaxies (e.g., observations of the detected sources (Owen et al. 1984) and Ekers et al. 1981). The most extreme example of this interac- has resulted in the discovery of many tailed sources. Poten- tion is the class of narrow-angle-tail sources (Ryle and Win- tial or known NAT sources were chosen from the literature dram 1968; Hill and Longair 1971; Rudnick and Owen and from the VLA snapshot survey of radio sources in Abell 1976). The NAT morphology is attributed predominantly to clusters (Owen et al. 1984). The sources were observed pri- the interaction of beams or clouds of radio luminous plasma marily in the A and B configurations of the VLA at 20 cm ejected by a moving galaxy with the intracluster medium (Thompson et al. 1980). The flux-density scale of Baars et al. (e.g., Miley et al. 1972; Wellington et al. 1973; Jaffe and (1977) was used. Perola 1973; Pacholczyk and Scott 1976; Begelman, Rees, The parameters of the observations are given in Table I. and Blandford 1979; Jones and Owen 1979; Christiansen, The source name is given in column 1. The Abell cluster Pacholczyk, and Scott 1981). The bending of the radio jets in number (Abell 1958) is given in column 2. Zw denotes a NATs provides important constraints on the physics of the Zwicky cluster (see Zwicky et al. 1961). The date of the ob- jets not available in straight jets. In principle, the study of servations is given in column 3. An asterisk marks observa- NATs can improve our understanding of the physical condi- tions taken from the Abell cluster survey (Owen et al. 1984). tions within the radio jets, as well as within the immediate The VLA configuration is given in column 4. The observing environment in the galaxy and in the intracluster medium. frequency and bandwidth in megahertz are given in columns However, the interpretation of the observations of the struc- 5 and 6, respectively. The integration time (in minutes) is ture of NATs is strongly affected by projection effects (Reyn- given in column 7. The angular resolutions are given in the olds 1980), as well as by the available sensitivity and resolu- captions to Fig. 1 and in the text. The linear/angular scale in tion. kiloparsecs/arcsecond is given in column 8. The distances were obtained from the redshifts in Table III, assuming a The purpose of this paper is to provide high-resolution, -1 -1 high-sensitivity maps of a large enough number of NATs so Hubble constant of = 75 km s Mpc and a decelera- that a representative sample can be constructed for statisti- tion parameter of q0 = 0.1. cal, as well as detailed, studies of their properties. The global The data were edited, calibrated, mapped, and CLEANed and statistical properties of a sample of 51 NATs in Abell as described by O’Dea (1984). In most cases, it was possible clusters are discussed by O’Dea and Owen (1985a, hereafter to add together data sets obtained in different VLA configu- referred to as paper II). Constraints on the properties of bent rations. This was desirable since it improved the (w, u) cover- radio jets are discussed by O’Dea (1984). Multifrequency ob- age considerably and permitted a map to be made of the servations of the prototypical NAT NGC 1265 are presented relatively large-scale structure with high resolution. A cor- by O’Dea and Owen (1985b, hereafter referred to as paper rection for attenuation by the primary beam was applied to III). all maps where the source was larger than —2' in size. The final noise level in the maps was typically —0.15 mJy- -1 -1 II. OBSERVATIONS AND DATA REDUCTION beam for the 1-hr observations and — 1 mJy beam for the snapshots (—10 min observations). The much larger The details of the source selection are given in paper II. noise in the snapshot maps is due mainly to the poorer («, u) Using the NRAO 300-ft. telescope, 1478 Abell clusters were coverage, which makes it more difficult to remove confusing sources properly. a) National Radio Astronomy Observatory is operated by Associated Uni- The positions of the optical identifications were measured versities, Inc., under contract with the National Science Foundation. on the PSS E prints to an accuracy of — 1" using the NRAO 927 Astron. J. 90 (6), June 1985 0004-6256/85/060927-27$00.90 © 1985 Am. Astron. Soc. 927 © American Astronomical Society • Provided by the NASA Astrophysics Data System 9270 . 928 C. P. O’DEA AND F. N. OWEN: RADIO SOURCES IN CLUSTERS OF GALAXIES 928 90 Table I. The parameters of the observations. Frequency Bandwidth Time Scale Source Cluster Array (MHz) (MHz) (Min) (kpc/”) 1985AJ 0039+211 0084 03-19-82 1452 50 2.1 0039-095 0085 05-08-81* 1413 25 10 1.0 03-19-82 1452 25 50 0039-097 0085 05-08-81* 1413 25 10 1.0 12-26-81* 1452 25 10 08-26-82 1452 25 50 0053-016 0119 12-26-81* 1452 25 10 0.86 08-26-82 1452 25 50 0053-015 0119 12-26-81* 1452 25 10 0.86 08-26-82 1452 25 50 0123-016 0194 12-26-81* 1452 25 10 0.36 08-26-82 1411 12.5 50 0154+319 0278 01-23-82 4885 50 50 1.8 05-30-82 4885 50 50 0256+132 0401 05- 1413 25 10 1.5 08-81* 01-23-82 C 1452 25 50 06- A 1452 25 50 25-82 0258+356 0407 05- B 1413 25 10 0.93 08-81* 12-26-81* C 1452 25 10 06- A 1452 25 50 25-82 0304-123 0415 12-26-81* B 1452 25 10 1.8 01-23-82 C 1452 25 10 03-19-82 A 1452 25 50 0309+411 0426 05-28-82 1452 25 50 0.35 0327+246 0439 03-19-82 1452 25 50 2.2 01-23-82 1452 25 10 0335+096 Zw 01-23-82 1452 25 10 0.70 03-19-82 1452 25 50 0431-134 0496 01-23-82 4885 50 50 0.62 0457+054 0526 09-20-80* 1465 25 10 1.1 05-08-81* 1413 25 10 08-26-82 1452 25 50 0647+693 0562 01-23-82 4885 50 50 2.2 0658+330 0567 09-25-82* 1452 25 10 2.6 0704+351 0568 05-08-81* 1413 25 10 1.6 12-26-81* 1452 25 10 03-19-82 1452 25 20 05-28-82 1452 25 50 0905-098 0754 09-25-82* 1452 25 10 1.0 08-26-82 1452 25 20 0907-091 0754 12-26-81* 1452 25 10 1.0 08-26-82 1452 25 10 1055+570 1132 03-19-82 1452 25 50 2.8 1108+411 1190 09-25-82* 1452 25 10 1.5 03-25-82 1452 25 50 1132+492 1314 08-06-82 1452 25 50 0.67 1244+699 1614 08-06-82 1452 25 50 3.3 1250-150 1631 05- 1413 25 10 1.1 08-81* 12-26-81* 1452 25 10 06- 1446 12.5 50 14-82 1256+282 1656 03-19-82 1452 25 50 1257+282 " 4 0.46 1330+507 1758 03-19-82 1452 25 50 6.1 09-25-82 1452 25 10 © American Astronomical Society • Provided by the NASA Astrophysics Data System 9270 . 929 C. P. O’DEA AND F. N. OWEN: RADIO SOURCES IN CLUSTERS OF GALAXIES 929 90 Table I. (continued) Frequency Bandwidth Time Scale Source Cluster Array (MHz) (MHz) (Min) (kpc/") 1985AJ 1339+266 1775 05- 81* 1413 25 10 1.4 08- 03-19- 82 1452 25 50 06- 82 4885 50 50 14- 1519+488 2064 03- 82 1452 25 50 2.2 19- 1556+274 2142 08-06- 82 1452 25 50 1.8 1615+351 Zw 04- 82 1452 25 50 0.60 05- 1615+425 2172 03-19- ■82 1452 25 50 2.8 1619+428 2183 01-23- ■82 1452 25 50 2.7 03-19- ■82 1452 25 50 1621+380 Zw 05- •82 1452 25 50 0.63 10- 1624+406 2197 08-06- ■82 1452 25 50 0.60 1658+326 2241 01-23- 82 1452 25 10 2.1 03-19- 82 1452 25 50 1709+397 2250 05-10- 82 1452 25 50 1.3 08-06- 82 1452 25 50 1712+638 2255 08-06-82 1452 25 1.7 1705+786 2256 06-14- 82 1446 12.5 50 1.2 1706+786 09-25- 82* 1452 25 10 1706+787 1707+787 1753+580 2289 03-19-82 1452 25 3.3 1850+702 2311 05-01-82 1452 25 10 1.6 08-06-82 1452 25 15 08-07-82 1452 25 50 1918+439 2319 08-07-82 1452 25 1.1 2316+184 2572 05-08-81* 1413 25 10 0.78 05-30-82 1452 25 50 08-07-82 1452 25 50 2322+143 2593 01-23-82 C 1452 25 10 0.87 03-19-82 A 1452 25 50 Observations taken from the VLA snapshot survey of Abell clusters by Owen et al.