Evolutionary versus dynamical time scales for the evolution of the central stars of planetary nebulae

McCarthy, James K.; Mould, Jeremy; Méndez, R. H.; Kudritzki, Rolf‐Peter; Husfeld, D.; Herrero, A.; Groth, Helen

doi:10.1086/168458

Cited by 40 publications

(25 citation statements)

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“…However, there is some disagreement when this comparison is made. McCarthy et al (1990) found a strong trend for old nebulae to be located at the position of young CSs. When the sample is biased toward low-mass progenitors, the tendency is in the opposite sense (see Gathier 1984 and some low-mass objects in the sample of McCarthy et al 1990), and young nebulae appear to be hosted by old CSs.…”

Section: Kinematical Versus Cs Agesmentioning

confidence: 91%

“…McCarthy et al (1990) found a strong trend for old nebulae to be located at the position of young CSs. When the sample is biased toward low-mass progenitors, the tendency is in the opposite sense (see Gathier 1984 and some low-mass objects in the sample of McCarthy et al 1990), and young nebulae appear to be hosted by old CSs. In order to investigate this observed disagreement between the kinematical and CS timescales, we have computed the kinematical age of the nebula derived from our models, and we plot it in Figure 20 versus the age of the CS.…”

Section: Kinematical Versus Cs Agesmentioning

confidence: 91%

“…At later stages of the evolution, when the sample is biased toward low-mass progenitors, the dynamical ages underestimate the evolutionary status of the CSs. McCarthy et al (1990) found transition times to be the most …”

Section: Kinematical Versus Cs Agesmentioning

confidence: 99%

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The Dynamical Evolution of the Circumstellar Gas around Low‐ and Intermediate‐Mass Stars. II. The Planetary Nebula Formation

Villaver

Manchado

Garcı́a-Segura³

2002

ApJ

121

151

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We have studied the effect of the mass of the central star (CS) on the gas evolution during the planetary nebula (PN) phase. We have performed numerical simulations of PN formation using CS tracks for six stellar core masses corresponding to initial masses from 1 to 5 M . The gas structure resulting from the previous asymptotic giant branch (AGB) evolution is used as the starting configuration. The formation of multiple shells is discussed in the light of our models, and the density, velocity, and H emission brightness profiles are shown for each stellar mass considered. We have computed the evolution of the different shells in terms of radius, expansion velocity, and H peak emissivity. We find that the evolution of the main shell is controlled by the ionization front rather than by the thermal pressure provided by the hot bubble during the early PN stages. This effect explains why the kinematical ages overestimate the age in young CSs. At later stages in the evolution and for low-mass progenitors the kinematical ages severely underestimate the CS age. Large (up to 2.3 pc), low surface brightness shells (less than 2000 times the brightness of the main shell) are formed in all of our models (with the exception of the 5 M model). These PN halos contain most of the ionized mass in PNe, which we find is greatly underestimated by the observations because of the low surface brightness of the halos.

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Section: Kinematical Versus Cs Agesmentioning

confidence: 91%

Section: Kinematical Versus Cs Agesmentioning

confidence: 91%

See 1 more Smart Citation

The Dynamical Evolution of the Circumstellar Gas around Low‐ and Intermediate‐Mass Stars. II. The Planetary Nebula Formation

Villaver

Manchado

Garcı́a-Segura³

2002

ApJ

121

151

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“…Actually, it will be interesting to use our model results in a future analysis to address the discrepancy between the evolutionary and dynamical ages of PNe (see e.g. McCarthy et al 1990). …”

Section: Expansion Velocitiesmentioning

confidence: 99%

Evolution of planetary nebulae

Marigo

Girardi

Groenewegen

et al. 2001

A&A

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Abstract. We present a new synthetic model to follow the evolution of a planetary nebula (PN) and its central star, starting from the onset of AGB phase up to the white dwarf cooling sequence. The model suitably combines various analytical prescriptions to account for different (but inter-related) aspects of planetary nebulae, such as: the dynamical evolution of the primary shell and surrounding ejecta, the photoionisation of H and He by the central star, the nebular emission of a few relevant optical lines (e.g. Hβ; He ii λ4686; [O iii] λ5007). Particular effort has been put into the analytical description of dynamical effects such as the three-winds interaction and the shell thickening due to ionisation (i.e. the thin-shell approximation is relaxed), that are nowadays considered important aspects of the PN evolution. Predictions of the synthetic model are tested by comparison with both findings of hydrodynamical calculations, and observations of Galactic PNe. The sensitiveness of the results to the model parameters (e.g. transition time, mass of the central star, H-/He-burning tracks, etc.) is also discussed. We briefly illustrate the systematic differences that are expected in the luminosities and lifetimes of PNe with either H-or He-burning central stars, which result in different "detection probabilities" across the H-R diagram, in both Hβ and [Oiii] λ5007 lines. Adopting reasonable values of the model parameters, we are able to reproduce, in a satisfactory way, many general properties of PNe, like the ionised mass-nebular radius relationship, the trends of a few main nebular line ratios, and the observed ranges of nebular shell thicknesses, electron densities, and expansion velocities. The models naturally predict also the possible transitions from optically-thick to optically-thin configurations (and vice versa). In this context, our analysis indicates that the condition of optical thinness to the H continuum plays an important role in producing the observed "Zanstra discrepancy" between the temperatures determined from H or He ii lines, as well as it affects the mass-increasing part of the ionised mass-radius relation. These predictions are supported by observational indications by Méndez et al. (1992). Another interesting result is that the change of slope in the electron density-nebular radius relation at Rion ∼ 0.1 pc, pointed out by Phillips (1998), is also displayed by the models and may be interpreted as the result of the progressive convergence of the PNe to the condition of constant ionised mass. Finally we would like to remark that, thanks to its computational agility, our synthetic PN model is particularly suitable to population synthesis studies, and it represents the basic ground from which many future applications will be developed.

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“…It is far from clear that the zero points of stellar evolutionary models correspond to those of the expanding shells ; a problem that has been remarked upon by McCarthy et al (1990), Gathier & Pottasch (1989), and Renzini (1989). Weidemann (1989), on the other hand, notes that such uncertainties are unlikely to a †ect the distribution of masses M CS to any marked degree.…”

Section: Introductionmentioning

confidence: 99%

The Validity of Mass Functions for the Central Stars of Planetary Nebulae

Phillips¹

2000

The Astronomical Journal

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It is commonly assumed that the distribution of masses for the central stars of planetary nebulae is strongly peaked about Such a mass function is similar to that deduced for white dwarfs. M CS + 0.6 M _ . We show in the following, however, that certain of the procedures used to evaluate are seriously N(M CS ) Ñawed and assume a nebular mass that is probably inappropriate. At the very least, the uncer-M NEB tainty in casts doubts upon the utility of these procedures, while the deduced functions M NEB N(M CS ) may be in error.

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Evolutionary versus dynamical time scales for the evolution of the central stars of planetary nebulae

Cited by 40 publications

References 0 publications

The Dynamical Evolution of the Circumstellar Gas around Low‐ and Intermediate‐Mass Stars. II. The Planetary Nebula Formation

The Dynamical Evolution of the Circumstellar Gas around Low‐ and Intermediate‐Mass Stars. II. The Planetary Nebula Formation

Evolution of planetary nebulae

The Validity of Mass Functions for the Central Stars of Planetary Nebulae

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