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1989ApJS...71..469Lockman

A Survey of Radio HII Regions in the Northern Sky

Lockman F. J.

Summary

Nearly 500 radio continuum sources near the Galactic plane at declinations >= -37^o were examined for radio recombination line emission to see if they might be HII regions. A total of 462 were detected, about half of these for the first time. The data are presented in an extensive table. Among the newly discovered nebulae are several with recombinations lines so narrow that their electron temperature must be < 4600 K. In one case the line width (in several transitions) is only 11.6 km/s, requiring T_e < 2900 K.

All observations were made using the NRAO 43 m telescope at Green Bank between 1982 and 1986, mainly in recombination line transitions near 3 cm where the telescope has a half-power beamwidth of about 3'. The source list was chosen primary from the 5 GHz inner Galaxy contunuum survey of Altenhoff et al. (1978), supplemented by objects from the surveys of Altenhoff et al. (1970), Reich et al. (1984), KR80, Felli and Churcwell (1972), Haynes+ (1979), Wendker (1984), and Day+ (1972).

	  Ojects not Detected
-----------------------------------------
    l       b     BRMS mK  Notes
-----------------------------------------
  6.490 + 0.084    5.1    W28 SNR
  6.648 + 0.084    4.2    W28 SNR
  8.989 +35.502    3.5    S33 B
 11.531 +36.350    3.1    S36 A
 13.456 + 0.156    3.5    SNR
 16.732 + 0.079    3.5    SNR
 19.961 - 0.175    3.5    SNR
 21.347 - 0.628    3.8    Extragalactic
 25.253 - 0.150    5.7    Extragalactic
 25.520   0.215    5.2
 28.600 - 0.126    4.0    SNR+HII+?
 28.917   0.250    4.0
 29.388   0.099    4.4    Extragalactic
 30.113   1.369    4.2
 33.496   0.196    3.5    Extragalactic
 78.107   1.731    5.2    gamma Cyg SNR
 78.324   2.468    5.7    gamma Cyg SNR
------------------------------------------
Table 1. HII regions detected
glong     glat       RA_DEC_B1950     T_L/mk+-     FWHM/km/s    V_LSR/kms  GMRS BRMS/mK Comments
----+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+
350.129 +0.088  17 16 06.5 -37 06 28   191  8.0    26.5  1.3    -70.3  0.5    14.5 15.5