DEFPOS H α observations of H ii regions

Abstract

We present H α emission line measurements of northern bright H ii regions selected from the Sharpless (1959) catalog near the Galactic plane ( b ⩽ ± 6°). A total of 10 H ii regions were observed with DEFPOS (Dual Etalon Fabry–Perot Optical Spectrometer) system at the f/48 Coude focus of 150 cm RTT150 telescope located at TUBITAK National Observatory (TUG) in Antalya/Turkey. The intensities, the local standard of rest (LSR) velocities ( V LSR ), and the linewidths (Full Width Half Maximum: FWHM) of the H α emission line from our observations were in the range of 84 to 745 Rayleigh ( R [one Rayleigh ( R) is 10 6/4 π photons cm −2 sr −1 s −1 = 2.4110 −7 erg cm −2 sr −1 s −1 at H α and corresponds to an emission measure ( EM = ∫ n e 2 dl ) of 2.3 pc cm −6 for a gas temperature of 8000 K, where n e is the averaged electron density within an emitting region in the interstellar medium; dl is distance element to the source region ( Haffner et al., 2003; Reynolds et al., 2005), 3 to −43 km s −1 and 30 to 73 km s −1, respectively. The LSR velocities and the linewidths from the data were obtained and compared with early results. We found that our results are in close agreement with them. Moreover, associated stars of some of the H ii regions were updated by analyzing their location, velocities, and brightness.