The populations of planetary nebulae in the direction of the Galactic bulge

Górny, S. K.; Stasińska, G.; Escudero, Alfonso; Costa, R. D. D.

doi:10.1051/0004-6361:20047064

Cited by 83 publications

(143 citation statements)

References 37 publications

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Section: Abundancessupporting

confidence: 61%

“…Despite this, the overall O/H ratio in PNG 003.6 + 03.1 agrees well with Górny et al (2004): 4.4 × 10 −4 (this work) compared with 4.0 × 10 −4 . Also, the O + /H + ratio from our work in 354.5 + 03.3 is consistent with that of Górny et al (2004). The elemental abundance of nitrogen and sulphur are also higher in our results than Górny et al (2004) for PNG 003.6 + 03.1 by factors of 2-3.…”

Section: Abundancessupporting

confidence: 61%

See 1 more Smart Citation

Abundances in Galactic bulge planetary nebulae from optical, ultraviolet and infrared observations

Smith

Zijlstra

Gęsicki

et al. 2017

Monthly Notices of the Royal Astronomical Society

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Iron suffers from high levels of depletion in the highly ionized environments of planetary nebulae, making the direct determination of undepleted elemental iron abundances difficult. Zinc, which does not suffer from the same depletion effects as iron, may be used as a surrogate element to measure iron abundances as there is an approximately constant zinc-to-iron ratio across a wide range of metallicities. In this paper, we report zinc abundances of six Galactic Bulge planetary nebulae determined from new observations taken with ISAAC on the Very Large Telescope, Chile, prior to the instrument's decommissioning as well as a further three based upon literature observations. UVES data of the sample planetary nebulae are presented and have been used to derive abundances, temperatures and densities of a variety of elements and ions. The abundances derived from the UVES data agree well with results from the literature. [Zn/H], determined from the ISAAC observations, is found to be generally sub-solar and [O/Zn] is found to be either consistent or enriched with respect to Solar.

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Section: Abundancessupporting

confidence: 61%

Section: Abundancessupporting

confidence: 61%

Abundances in Galactic bulge planetary nebulae from optical, ultraviolet and infrared observations

Smith

Zijlstra

Gęsicki

et al. 2017

Monthly Notices of the Royal Astronomical Society

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“…The model profiles are broadened by a Gaussian with FWHM of 11 km s −1 in order to comply with the spectral resolution of the observations. Crossed symbols mark objects which are known to posses [WC]-type central stars (see Górny et al 2004). and 50% for the slowly expanding objects (filled circles in Fig. 37) and usually less for the faster expanding PNe with doubly peaked profiles.…”

Section: Expansion Propertiesmentioning

confidence: 99%

“…Spectroscopy done by Górny et al (2004) revealed that the sample of bulge PNe used by Richer et al (2009Richer et al ( , 2010a contains several objects with WC central stars, which are marked in Fig. 37 by crossed symbols.…”

Section: Expansion Propertiesmentioning

confidence: 99%

The evolution of planetary nebulae

Schönberner

Jacob

Sandín

et al. 2010

A&A

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Aims. By means of hydrodynamical models we do the first investigations of how the properties of planetary nebulae are affected by their metal content and what can be learned from spatially unresolved spectrograms of planetary nebulae in distant stellar systems. Methods. We computed a new series of 1D radiation-hydrodynamics planetary nebulae model sequences with central stars of 0.595 M surrounded by initial envelope structures that differ only by their metal content. At selected phases along the evolutionary path, the hydrodynamic terms were switched off, allowing the models to relax for fixed radial structure and radiation field into their equilibrium state with respect to energy and ionisation. The analyses of the line spectra emitted from both the dynamical and static models enabled us to systematically study the influence of hydrodynamics as a function of metallicity and evolution. We also recomputed selected sequences already used in previous publications, but now with different metal abundances. These sequences were used to study the expansion properties of planetary nebulae close to the bright cut-off of the planetary nebula luminosity function. Results. Our simulations show that the metal content strongly influences the expansion of planetary nebulae: the lower the metal content, the weaker the pressure of the stellar wind bubble, but the faster the expansion of the outer shell because of the higher electron temperature. This is in variance with the predictions of the interacting-stellar-winds model (or its variants) according to which only the central-star wind is thought to be responsible for driving the expansion of a planetary nebula. Metal-poor objects around slowly evolving central stars become very dilute and are prone to depart from thermal equilibrium because then adiabatic expansion contributes to gas cooling. We find indications that photoheating and line cooling are not fully balanced in the evolved planetary nebulae of the Galactic halo. Expansion rates based on widths of volume-integrated line profiles computed from our radiation-hydrodynamics models compare very well with observations of distant stellar system. Objects close to the bright cut-off of the planetary nebula luminosity function consist of rather massive central stars (>0.6 M ) with optically thick (or nearly thick) nebular shells. The halfwidth-half-maximum velocity during this bright phase is virtually independent of metallicity, as observed, but somewhat depends on the final AGB-wind parameters. Conclusions. The observed expansion properties of planetary nebulae in distant stellar systems with different metallicities are explained very well by our 1D radiation-hydrodynamics models. This result demonstrates convincingly that the formation and acceleration of a planetary nebula occurs mainly because of ionisation and heating of the circumstellar matter by the stellar radiation field, and that the pressure exerted by the shocked stellar wind is less important. Determinations of nebular abundances by means of photoionisa...

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“…Dots represent the sample of Escudero, Costa & Maciel (2004) and crosses other data Additional results can be found investigating a special subsample of bulge PN: those with Wolf-Rayet central stars. Górny et al (2004) investigate 164 PN toward the bulge, merging data from the literature with new observations, finding 18 objects with WR central stars and 24 other central stars with weak emission lines. Investigating these objects they found no difference between oxygen abundances of normal PN and those with WR central stars, which implies that the oxygen abundances in WR are not significantly affected by nucleosynthesis or mixing in these objects.…”

Section: The Galactic Bulgementioning

confidence: 99%

Planetary nebulae as probes for galactic chemical evolution

Costa¹,

Maciel²

2006

IAU

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Abstract. The role of planetary nebulae as probes for the galactic chemical evolution is reviewed. Their abundances throughout the Galaxy are discussed for key elements, in particular oxygen and other alpha elements. The abundance distribution derived from planetary nebulae leads to the establishment of radial abundance gradients in the galactic disk that are important constraints to model the chemical evolution of the Galaxy. The radial gradient, well determined for the solar neighborhood, is examined for distinct regions. For the galactic anticenter in particular, the observational data confirm results from galactic evolution models that point to a decreasing in the gradient slope at large galactocentric distances. The possible time evolution of the radial gradient is also examined comparing samples of planetary nebulae of different ages, and the results indicate that a flattening in the gradient occurred, which is confirmed by some galactic evolution models. The galactic bulge is another important region whose modeling can be constrained by observational results obtained from planetary nebulae. Results derived in the last few years indicate that bulge nebulae have an abundance distribution similar to that of disk objects, however with a larger dispersion.

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The populations of planetary nebulae in the direction of the Galactic bulge

Cited by 83 publications

References 37 publications

Abundances in Galactic bulge planetary nebulae from optical, ultraviolet and infrared observations

Abundances in Galactic bulge planetary nebulae from optical, ultraviolet and infrared observations

The evolution of planetary nebulae

Planetary nebulae as probes for galactic chemical evolution

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