Observations of planetary nebulae in the Galactic Bulge
نویسندگان
چکیده
High quality spectrophotometric observations of 30 Planetary Nebulae in the Galactic Bulge have been made. Accurate reddenings, plasma parameters, and abundances of He, O, N, S, Ar, Cl are derived. We find the abundances of O, S, Ar in the Planetary Nebulae in the Galactic Bulge to be comparable with the abundances of the Planetary Nebulae in the Disk, high abundances being maybe slightly more frequent in the Bulge. The distribution of the N/O ratio does not present in the Galactic Bulge Planetary Nebulae the extension to high values that it presents in the Disk Planetary Nebulae. We interpret this as a signature of the greater age of Bulge Planetary Nebulae. We thus find the Bulge Planetary Nebulae to be an old population, slightly more metal-rich than the Disk Planetary Nebulae. The population of the Bulge Planetary Nebulae shows hence the same characteristics than the Bulge stellar population.
منابع مشابه
Radial velocities of planetary nebulae towards the Galactic bulge
Accurate radial velocities for a sample of 71 planetary nebulae, mostly located in the direction of the Galactic Centre, are presented. Most of the nebulae discussed in this paper are likely members of the Galactic bulge, based on their radial velocity, longitude and derived distance. The data give a large improvement over existing catalogues, doubling the sample of bulge planetary nebulae with...
متن کاملNew abundances of planetary nebulae in the Galactic Bulge⋆
New observations and derived chemical abundances are reported for a sample of 57 bulge planetary nebulae (PN). Together with our previous results, a total of over a hundred objects have been analyzed, which constitute one of the largest samples of bulge nebulae studied under homogeneous conditions, including equipment and reduction procedures. In general, our data show a good agreement with som...
متن کاملRadio observations of new galactic bulge planetary nebulae
We observed 64 newly identified galactic bulge planetary nebulae in the radio continuum at 3 and 6 cm with the Australia Telescope Compact Array. We present their radio images, positions, flux densities, and angular sizes. The survey appears to have detected a larger ratio of more extended planetary nebulae with low surface brightness than in previous surveys. We calculated their distances acco...
متن کاملThe Galactic Bulge: the Stellar and Planetary Nebulae Populations
We compare abundances patterns in the Bulge for elements observed in stars and in planetary nebulae. Some α elements, like Mg and Ti, are overabundant in respect to Fe, and others are not, like He, O, Si, S, Ar, Ca. The first ones favor a quick evolution of the Galactic Bulge, and the seconds a much slower one.
متن کاملPlanetary Nebulae: Abundances and Abundance Gradients
In this work, a review is given of some recent results and problems involved in the determination of chemical abundances of galactic planetary nebulae, particularly regarding disk and bulge objects.
متن کامل