SIMBAD references

Up to now, 10 planetary nebulae have been regarded as halo planetary nebulae (halo PNe). We obtained low- and moderate-dispersion spectra of the spatially resolved halo planetary nebula H4-1 in the wavelength region of 3700-6800 Å with the Cassegrain Spectrograph of the 74 inch telescope. At moderate dispersions, we were able to observe [O III] λλ4959, 5007 and Hα of H4-1 at several position angles (P.A.). We assumed that the widths of these emission-line profiles were due to Doppler broadening and that these emission lines were composed of several Gaussian components. Multiple Gaussian deconvolution analysis of such emission lines indicated H4-1 has broad wing components (∼600 km.s^–1) at P.A. 135° and 180°. We think H4-1 has a ``bipolar flow'' between P.A. 135° and 180°. From low-dispersion spectra, we confirm that H4-1 is a metal-poor PN. In spite of the lack of spatially resolved images at present, we believe that H4-1 has a bipolar flow and that its axis is almost parallel to the line of sight, with a small inclination angle.