scholarly journals Chemical Abundances and Dust in Planetary Nebulae in the Galactic Bulge

2008 ◽  
Vol 680 (2) ◽  
pp. 1206-1221 ◽  
Author(s):  
S. Gutenkunst ◽  
J. Bernard‐Salas ◽  
S. R. Pottasch ◽  
G. C. Sloan ◽  
J. R. Houck
Keyword(s):  
Planetary Nebulae ◽  
Galactic Bulge ◽  
Chemical Abundances

scholarly journals Chemical Abundances in Galactic Bulge Pn

1993 ◽  
Vol 155 ◽  
pp. 581-581 ◽  
Author(s):  
N.A. Walton ◽  
M.J. Barlow ◽  
R.E.S. Clegg
Keyword(s):  
Galactic Disk ◽  
Planetary Nebulae ◽  
Solar Neighbourhood ◽  
Galactic Bulge ◽  
Low Resolution ◽  
Chemical Abundances ◽  
The Mean ◽  
Optical Spectrophotometry ◽  
High Metallicity

We present abundance determinations, in particular of carbon, and C/O ratios, for 11 Galactic bulge planetary nebulae (PN) based on our low resolution UV data from IUE observations and optical spectrophotometry from the Anglo-Australian Telescope. We compare the observed abundances with those predicted by dredge-up theory for the high metallicity Galactic bulge. The sample abundances are also contrasted with the abundances found for PN in the Galactic disk. The mean C/O ratio for the bulge PN is significantly lower than that found for Galactic disk PN. Further, we present an abundance analysis of the very metal-poor bulge PN M2-29. From an analysis of the differential extinction found from the observed ratios of the He ii 1640,4686Å lines, we find that the ultraviolet reddening law towards the bulge is steeper than in the solar neighbourhood.

scholarly journals The evolution of the Galactic bulge from planetary nebulae

2007 ◽  
Vol 3 (S245) ◽  
pp. 365-366
Author(s):  
Walter J. Maciel ◽  
R. D. D. Costa ◽  
A. V. Escudero
Keyword(s):  
Observational Data ◽  
Chemical Evolution ◽  
Planetary Nebulae ◽  
Observational Constraints ◽  
Galactic Bulge ◽  
Full Understanding ◽  
Chemical Abundances

AbstractWe have used our dataset on the abundances of planetary nebulae (PN) to study the chemical evolution of the Galactic bulge. We have derived several relations involving the chemical abundances and computed three classes of models for the Galactic bulge: (i) one-zone, single-infall models, (ii) one-zone, double-infall models and (iii) multizone, double infall models. We conclude that part of the observational data can be understood in terms of the simpler models, but the full understanding of all observational constraints can only be explained by more complex multizone models.

scholarly journals The population of planetary nebulae near the Galactic Centre: chemical abundances

2016 ◽  
Vol 12 (S323) ◽  
pp. 339-340
Author(s):  
M. Mollá ◽  
O. Cavichia ◽  
R. D. D. Costa ◽  
W. J. Maciel
Keyword(s):  
Luminosity Function ◽  
Planetary Nebulae ◽  
Galactic Centre ◽  
Physical Parameters ◽  
Chemical Compositions ◽  
Galactic Bulge ◽  
Chemical Abundances ◽  
Chemical Enrichment ◽  
History Of ◽  
Low Dispersion

AbstractIn this work, we report physical parameters and abundances derived for a sample of 15 high extinction planetary nebulae located in the inner 2° of the Galactic bulge, based on low dispersion spectroscopy secured at the SOAR telescope using the Goodman spectrograph. The new data allow us to extend our database including older, weaker objects that are at the faint end of the planetary nebulae luminosity function. The data provide chemical compositions for PNe located in this region of the bulge to explore the chemical enrichment history of the central region of the Galactic bulge. The results show that the abundances of our sample are skewed to higher metallicities than previous data in the outer regions of the bulge. This can indicate a faster chemical enrichment taking place at the Galactic centre.

scholarly journals The Sulphur Abundance in Planetary Nebulae

2003 ◽  
Vol 209 ◽  
pp. 385-386
Author(s):  
Mezak A. Ratag
Keyword(s):  
Planetary Nebulae ◽  
Theoretical Models ◽  
Galactic Bulge ◽  
Chemical Abundances

Ratag et al (1997) determined the chemical abundances of He, O, N, Ne, S, Ar, and Cl in ~110 planetary nebulae which are likely to be in the Galactic Bulge. The abundances are derived by employing theoretical nebular models as interpolation devices in establishing the ICFs. The overall agreement between the abundances obtained by employing the model-ICFs and those derived from the theoretical models is reasonably good. Based on this, it is of interest to study the reliability of various ICFs as well as to derive some alternative ICFs. The focus of the present study is sulphur.

scholarly journals Planetary nebulae and the chemical evolution of the galactic bulge: New abundances of older objects

2011 ◽  
Vol 7 (S283) ◽  
pp. 326-327 ◽  
Author(s):  
Oscar Cavichia ◽  
Roberto D. D. Costa ◽  
Mercedes Mollá ◽  
Walter J. Maciel
Keyword(s):  
Chemical Evolution ◽  
Planetary Nebula ◽  
Luminosity Function ◽  
Planetary Nebulae ◽  
Physical Parameters ◽  
Galactic Bulge ◽  
Chemical Abundances ◽  
The Galaxy ◽  
Low Dispersion ◽  
Chemical Evolution Model

AbstractIn view of their nature, planetary nebulae have very short lifetimes, and the chemical abundances derived so far have a natural bias favoring younger objects. In this work, we report physical parameters and abundances for a sample of old PNe located in the galactic bulge, based on low dispersion spectroscopy secured at the SOAR telescope using the Goodman Spectrograph. The new data allow us to extend our database including older, weaker objects that are at the faint end of the planetary nebula luminosity function (PNLF). The results show that the abundances of our sample are lower than those from our previous work. Additionally, the average abundances of the galactic bulge do not follow the observed trend of the radial abundance gradient in the disk. These results are in agreement with a chemical evolution model for the Galaxy recently developed by our group.

scholarly journals Chemical Enrichment and Central Star Properties

1993 ◽  
Vol 155 ◽  
pp. 572-572
Author(s):  
C.Y. Zhang
Keyword(s):  
Planetary Nebulae ◽  
Central Star ◽  
Agb Stars ◽  
Physical Processes ◽  
Chemical Abundances ◽  
Core Mass ◽  
Chemical Enrichment ◽  
The Core ◽  
Stellar Temperature ◽  
Independent Parameters

We have selected a sample of planetary nebulae, for which the core masses are determined using distance-independent parameters (Zhang and Kwok 1992). The chemical abundances of He, N, O, and C are taken from the literature for them. Relationships of the ratios of He/H, N/O, and C/O with various stellar parameters of planetary nebulae (PN), such as the core mass, the mass of the core plus the ionized nebular gas, the stellar age and temperature, are examined. It is found that the N/O increases with increasing mass, while the C/O first increases and then decreases with the core mass. No strong correlation seems to exist between the He/H and the core mass. A correlation of the N/O and He/H with the stellar temperature exists. The current dredge-up theory for the progenitor AGB stars cannot satisfactorily account for these patterns of chemical enrichment in PN. Furthermore, the correlations of the N/O and He/H with the stellar age and temperature indicate that besides the dredge-ups in the RG and AGB stages, physical processes that happen in the planetary nebula stage may also play a role in forming the observed patterns of chemical enrichment in the planetary nebulae.

scholarly journals Analysis of chemical abundances in planetary nebulae with [WC] central stars

2013 ◽  
Vol 558 ◽  
pp. A122 ◽  
Author(s):  
Jorge García-Rojas ◽  
Miriam Peña ◽  
Christophe Morisset ◽  
Gloria Delgado-Inglada ◽  
Adal Mesa-Delgado ◽  
...  
Keyword(s):  
Planetary Nebulae ◽  
Chemical Abundances ◽  
Central Stars
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