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Planetary nebulae in M 32 and the bulge of M 31: Line intensities and oxygen abundances

We present spectroscopy of planetary nebulae in M 32 and in the bulge of M 31 that we obtained with the MOS spectrograph at the Canada-France-Hawaii Telescope. Our sample includes 30 planetary nebulae in M 31 and 9 planetary nebulae in M 32. We also observed one HII region in the disk of M 31. We detected [OIII]λ4363 in 18 of the planetary nebulae, 4 in M 32 and 14 in the bulge...

Optical line profiles of the Helix planetary nebula (NGC 7293) to large radii

New, very long (25 arcmin), cuts of spatially resolved profiles of the Hα and [N ii] optical emission lines have been obtained over the face of the Helix planetary nebula, NGC 7293. These directions were chosen to supplement previous similar, though shorter, cuts as well as crossing interesting phenomena in this nebular envelope. In particular, one new cut crosses the extremes of...

The emission and kinematic structures of the bipolar planetary nebula M 1-8

We have undertaken echelle spectroscopy and narrow-band line imaging of the bipolar planetary nebula M 1-8. This has permitted us to map the outflow in [N ii]λλ 6548+6583 Å, Hα, and in thev= 1–0 S(1) transition of H2 at λ 2.122 μm. It has also permitted us to acquire high-resolution spectra for [N ii]λ 6583 Å, Hα and He iiλ 6560 Å. Our observations support the results of a...

Distance to NGC 253 based on the planetary nebula luminosity function

We identify a sample of 14 planetary nebulae in the nearby starburst disc galaxy NGC 253, using broad- and narrow-band imaging. A simple model of the stellar and dust layers in the galaxy shows that planetary nebula magnitudes are not statistically affected much by extinction. The luminosity function of the planetary nebulae is fitted with models accounting for dust, which leads...

The kinematics of the large western knot in the halo of the young planetary nebula NGC 6543

A detailed analysis of the dominant ionized knot in the halo of the planetary nebula NGC 6543 is presented. Observations were made at high spectral and spatial resolution of the [O iii]λ5007-Å line using the Manchester echelle spectrometer combined with the 2.1-m San Pedro Martir Telescope. A 20-element multislit was stepped across the field to give almost complete spatial...

The kinematics of the most oxygen-poor planetary nebula PN G 135.9+55.9

PN G 135.9+55.9 is a compact, high excitation nebula that has been identified recently as the most oxygen-poor halo planetary nebula. Given its very peculiar characteristics and potential implications in the realms of stellar and Galactic evolution, additional data are needed to firmly establish its true nature and evolutionary history. Here we present the first long-slit, high...

Theoretical models of the planetary nebula populations in galaxies: The ISM oxygen abundance when star formation stops

Using theoretical models of the planetary nebula populations in galaxies, we investigate whether the current oxygen abundances in bright planetary nebulae can be used to predict the oxygen abundance in the interstellar medium when star formation stopped. These models successfully reproduce a constant planetary nebula luminosity function (PNLF) peak luminosity, the PNLF shape in...

The enigma of the oldest ‘nova’: the central star and nebula of CK Vul

CK Vul is classified as, amongst others, the slowest known nova, a hibernating nova or a very late thermal pulse object. Following its eruption in ad 1670, the star remained visible for 2 yr. A 15-arcsec nebula was discovered in the 1980s, but the star itself has not been detected since the eruption. We here present radio images which reveal a 0.1-arcsec radio source with a flux...

IC 10: More evidence that it is a blue compact dwarf

2 Send o print requests to: M. G. Richer 3 Observatorio Astronomico Nacional, Instituto de Astronom a , UNAM, PO Box 439027, San Diego, CA 92143-9027 , USA 4 Department of Astronomy and Isaac Newton