Emission Line Profiles in the Planetary Nebulae IC 4593 and NGC 6153

Abstract

The Planetary Nebulae IC 4593 and NGC 6153 are two rather compact objects not well studied. The nebula IC 4593 is about 12 arcsec in diameter and has a central star of Type 07 f; while the southern nebula NGC 6153 is about 22 arcsec in diameter and its central star is faint and of unknown spectral type. Using a high-resolution scanning Fabry-Pérot spectrometer we have made profile measurements of emission lines Hα λ6563 A, [O III] λ5007 A, and [N II] λ6584 A in the central regions of these two nebulae. We have found expansion velocities for IC 4593 of 40 km s⁻¹ in [N II] and 16 km s⁻¹ in [O III]. In the case of NGC 6153, we have obtained expansion velocities of 15 km s⁻¹ in [N II] and 13 km s⁻¹ in [O III] line. The profiles in Hα in both the nebulae dis not show a double peaked feature due to the larger thermal broadening. In the case of IC 4593, both [O III] and [N II] profiles showed complex structures. These results and their interpretation will be discussed.