Ultra Steep Spectrum Radio Sources I.

(OCR+proof by H.Andernach 2/97)

NOTE to this electronic version: The published table has two typos for the names of 4C61.19 ("1.19") and 4C28.58 ("4C 8.58"). They were corrected here.

a 4C26.38 is made up of two physically distinct ultra steep spectrum radio sources 4C26.38N and 4C26.38S. Their fluxes are confused in the finding surveys. Those two objects are discussed in detail in Paper II.

NOTE.--The completeness of the sample is discussed in the text. The integrated 178MHz flux densities are from. (5) and (6) and the integrated 1415 and 4995 MHz flux densities are from (7). Positions given are from the cited reference and represent (i) the radio core if detected or (ii)the optical identification. Details are given in Tables 3 & 4, the figures, and the discussion. As discussed in the text, spectroscopy has been attempted on all sources, thus the absence of a redshift indicates no strong emission lines between 5000 - 7500 A. These sources are likely to have 1< z< 1.6. The eight objects with z > 2 are discussed in Paper II.

REFERENCES.

(1) this work;
(2) Paper II, Chambers et al. 1996
(3) Chambers, Miley, van Breugel 1990
(4) Chambers, Miley, van Breugel 1988;

Table 1. Ultra steep spectrum 4C sources                                   a178 a1415 LAS
No. 4Cname  RA_1950    DEC_1950  b/deg  z     R      I   S178 S1485 S4995  1415  4995  " ID ref
----+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+
1  4C46.01  004037.442 +470012.0 -15          22.3        5.00 0.46  0.13 -1.15 -1.00 12 Gal 1
2  4C49.06  012417.900 +493058.0 -13         >24.0  24.0  4.10 0.26  0.05 -1.33 -1.36 17 Gal 1

Table 2. Ultra steep spectrum 3C sources         Flux Density (Jy)  a178 a1485 LAS
No. 3Cname  RA_1950  DEC_1950  b/deg  z    Vmag   S178 S1485 S4995  1485  4995  " ID ref
----+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----
1  3C28    005309.12 +470011.0 -37 0.195  17.6  17.93  1.78  0.47 -1.12 -1.05  30 Gal  1

Table 4. Radio total intensity and polarization data  a1465 a4885
No. Name   obj  RA_B1950   DEC_1950 S1465  S4885 S14695 P1465  P4885 P14695    DP   /4885 14965
----+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+-

a) True fluxes are expected to be higher than quoted for these diffuse sources due to insuflicent UV coverage.

b) Lobe and hotspot combined in aperature.

c) The 2cm map of 4C48.45 was a 4.0" resolution and cannot be compared with the 1.2" data.

REFERENCES.

 1 Riley & Pooley 1978
 2 Jenkins, Pooley, & Riley 1977
 3 Leahy, Muxlow, & Stophens 1989
 4 Fanti et al. 1990, and Akujor & Garrinton 1995
 5 Owen & Puschell 1984
 6 Burns et al. 1984
 7 Bridle et al. 1994
 8 Burns et al. 1984
 9 Pooley & Henbest 1974
10 van Breugel and Spinrad priv. comm.
11 Akujor & Garrinton 1995
12 Swarup, Sinha, & Saikia 1982
13 McCarthy et al. 1990
14 van Breugel & Fomalont 1984
15 Burns, Schwendeman, & White 1983
16 Chambers, Miley, & Joyce 1988
17 Leahy, Muxlow, & Stophens 1989
18 Feigelson, Isobe, & Kembhavi 1984

1996ApJS 106 247Chambers+ Ultra Steep Spectrum Radio Sources II.

(OCR+proof by H.Andernach 2/97)

NOTE: Errors for sp.ind (a1465/4885) for 4C26.38S seem too high... a typo? H.A. 2/97

a) Chambers, Miley, van Breugel 1990;

b) Radio objects 4117D and 4117E are previous1y uncatalogued, see text. Due to radial smearing, the positions of 4117D in particular is likely to be ~1" closer to the map center (north) than these coordinates.

NOTE. Low frequency flux measurements are given in Table 1 and Figure 2.

Table  2. Observational Parameters of Radio Emission                         a178   a1465       a4885      Pol  beam
Object    RA_DEC_B1950         aperture/"  S1465/mJy S_4885/mJy S_14965/mJy  1465   4885  +-     14965      %    "
----+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+--
4C60.07   050825.80 +602718    10.9  2.6  146.  8.    25.3 1.5    4.3  0.5  -1.45  -1.46 0.09  -1.58 0.15        1.2 
A         050825.340+602719.2   3.0  2.6   80.1 4.    18.2 0.9    3.1  0.5         -1.24 0.07  -1.58 0.15   7.7  1.2