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Date and Time of the Query: 2019-06-19 T06:53:56 PDT
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For refcode 1993A&A...275..534M:
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Copyright by European Southern Observatory (ESO). Reproduced by permission
1993A&A...275..534M The bright end of the planetary nebula luminosity function Mendez, R. H.; Kudritzki, R. P.; Ciardullo, R.; Jacoby, G. H. Abstract. We describe a procedure for the numerical simulation of the planetary nebula luminosity function (PNLF). First of all we collect information about selected PNs in our Galaxy, construct the local cumulative PNLF, and show that optically thin PNs must be predominant at the bright end of the PNLF in our Galaxy and in the Magellanic Clouds. Then we model the PNLF in such a way that sample size, population age and partial absorption of stellar ionizing photons can be systematically studied. Our procedure avoids nebular models, but it is constrained as much as possible by observational evidence. We use a broader central star mass distribution than adopted by Jacoby (1989); this broader distribution is in better agreement with the observed white dwarf mass distribution in our Galaxy. As a by-product of our approach we present an improved correlation between stellar T_eff_ and nebular relative intensity [O III] AS 007 I Hp, calibrated using stellar effective temperatures that were determined from NLTE model atmosphere studies. With our simulated PNLFs we confirm previous suggestions that the observed cutoff at the bright end of the PNLF depends on sample size and population age; and we show how the cutoff is affected by the predominance of optically thin PNs in the sample. We obtain satisfactory fits to the observed PNLFs of the LMC and M 31, which gives us confidence in the reliability of our approach. The combination of the three effects (sample size, population age, partial absorption of stellar ionizing photons), operating on a broader central star mass distribution, produces distances which are very similar to those determined using the earlier formulation of the PNLF method. In particular, we obtain a distance modulus of 30.9+/-0.4 mags. for the Virgo cluster. We confirm low values for the specific PN formation rate xi, and also confirm the existence of a correlation between xi and the luminosities and intrinsic colors of galaxies. Possible interpretations of this correlation are discussed. In general, our models of the PNLF indicate its potential value not only for extragalactic distance determinations but also for studies of the initial-to-final mass relation and related mass loss processes in stars of early-type galaxies. Key words: planetary nebulae: general, post-AGB stars, galaxies: distances and redshifts, stars: mass function
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