## 2. Nonlinear Cepheid modelsThe overall strategy of nonlinear model construction was the same
as that discussed in Aikawa & Antonello (2000; hereinafter
Paper I). The adopted chemical composition was
,
and , and the opacity (s92 364) was
that supplied by the OP project (Seaton et al. 1994), with OPTFIT code
(Seaton 1993) for fitting and smoothing of the opacity tables. We
assumed the Another relation was assumed for comparison purposes: It was obtained simply by shifting the zero point in relation (1)
in the way required by Wood et al. (1997) to explain the light curve
of HV 905 in LMC. The theoretical blue edge was calculated with linear
nonadiabatic LNA analysis using Castor's type code for a given mass
and the corresponding luminosity, and the values of the effective
temperature of the model sequences
were chosen 200 K and 400 K smaller than the corresponding
blue edge. We will call the model sequence obtained with Eqs. (1)
and (2) as sequence (a) and (b), respectively. Fig. 1 shows the
location of the sequences in the
log-log
© European Southern Observatory (ESO) 2000 Online publication: December 11, 2000 |