Emission-Line Profiles in Planetary Nebulae

1966 ◽  
Vol 145 ◽  
pp. 697 ◽  
Author(s):  
D. E. Osterbrock ◽  
J. S. Miller ◽  
D. W. Weedman
1968 ◽  
Vol 34 ◽  
pp. 267-269
Author(s):  
Donald E. Osterbrock

This research was undertaken with the idea of measuring as accurately as possible the internal-velocity distribution in planetary nebulae, in order to compare the observational measurements with hydrodynamical models of expanding nebulae. Much of the work was done in collaboration with J. S. Miller and D.W. Weedman. All the observational data were obtained photographically with the Coudé spectrograph of the 100-inch telescope at Mt. Wilson, using an image rotator, a 900 line/mm grating, and an F/5-2 camera, giving a dispersion of about 4 Å/mm in the blue and about 6 Å/mm in the red. The measured velocity resolution is approximately 5–6 km/sec. The data for five nebulae have been published (Osterbrock et al., 1966) while data for three more, NGC 2392, NGC 3242, and IC 418 are discussed here for the first time.


2003 ◽  
Vol 209 ◽  
pp. 321-322
Author(s):  
J. R. Walsh ◽  
L. Walsh

There is a wealth of evidence for the presence of dust in PN from continuum and line emission in the IR, spatially varying extinction and ERE emission in the optical and strength of resonance lines in the UV. The dust emits strongly in the IR but in the UV-optical absorbs and scatters the radiation from the central star and the gaseous emission envelope. Linear polarization of PN light is thus an expected consequence of the presence of dust both within and outside the ionized region. Intrinsic scattering haloes of PN can be confused with local (telescope + atmospheric) scattering; polarimetry however allows the morphology of a dusty halo to be studied. Spectropolarimetry of emission line profiles allows the kinematics of the dust relative to the gaseous emission to be uniquely studied. Polarization contributes to understanding the scattering properties of the grains in PN and how they relate to those of the general ISM to which they will subsequently contribute.


2006 ◽  
Vol 2 (S234) ◽  
pp. 465 ◽  
Author(s):  
Christophe Morisset ◽  
Grazyna Stasinska

1989 ◽  
Vol 131 ◽  
pp. 189-189
Author(s):  
D.P.K. Banerjee ◽  
B. G. Anandarao

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.


1989 ◽  
Vol 131 ◽  
pp. 191-191
Author(s):  
S. Cristiani ◽  
F. Sabbadin ◽  
S. Ortolani

High (CES spectrograph + RETICON at the CAT telescope) and low (B&C spectrograph + CCD at the 2.2-m telescope) resolution spectra of selected, southern planetary nebulae allowed to obtain the Hα and [NII] emission line profiles and the nebular emission line intensities in the spectral range λλ3650-9400 A. The Hα and [N II] emission line parameters were derived following the procedure used by Sabbadin (Monthly Not. Roy. Astron. Soc., 209, 889, 1984) and Ortolani and Sabbadin (Astron. Astrophys. Suppl. Series, 62, 17, 1985). Table 1 contains the relevant data for eight nebulae of the sample.


1994 ◽  
Vol 144 ◽  
pp. 421-426
Author(s):  
N. F. Tyagun

AbstractThe interrelationship of half-widths and intensities for the red, green and yellow lines is considered. This is a direct relationship for the green and yellow line and an inverse one for the red line. The difference in the relationships of half-widths and intensities for different lines appears to be due to substantially dissimilar structuring and to a set of line-of-sight motions in ”hot“ and ”cold“ corona regions.When diagnosing the coronal plasma, one cannot neglect the filling factor - each line has such a factor of its own.


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