Internal Motions of Faint PN Halos

You-Hua Chu, George H. Jacoby
1989 Symposium - International astronomical union  
We have obtained long-slit echelle observations of faint halos for 10 PNe - NGC 2022, 2438, 6210, 6309, 6543, 6720, 6751, 6826, 6891, and 7662. Only NGC 2022 and 6720 have linesplits indicative of a hollow expanding-shell structure. The others have observed FWHM ranging from 13 to 47 km/s in the [O III]λ5007 line, with an instrumental FWHM of 9–10 km/s. We have subtracted the instrumental and thermal widths and made geometric corrections to derive the expansion velocities.
doi:10.1017/s0074180900138082 fatcat:255hnwbl6jbubpcykrhz74vpry