Theoretical Models for Classical Cepheids: VII. Metallicity effects on the Cepheid distance scale

Details Theoretical Models for Classical Cepheids: VII. Metallicity effects on the Cepheid distance scale Theoretical Models for Classical Cepheids: VII. Metallicity effects on the Cepheid distance scale

2000-06-16

arxiv.org/abs/astro-ph/0006228v1

Astron.Astrophys.359:1059-1067,2000

Astronomy and Astrophysics

Astrophysics

22 pages, 6 postscript figures, accepted for publication on Astronomy and Astrophysics

Scientific paper

We use theoretical Period-Luminosity and Period-Luminosity-Color relations in the VI passbands, as based on nonlinear, nonlocal and time-dependent convective pulsating models, to predict the reddening and true distance modulus of distant Cepheids observed with the Hubble Space Telescope. By relying on the pulsating models with metal content Z=0.008, we find that the theoretical predictions agree to the values obtained by the Extragalactic Distance Scale Key Project on the basis of empirical Period-Luminosity relations referenced to LMC variables. In the meantime, from the theoretical relations with Z=0.004 and 0.02 we find that the predicted E(B-V) and mu_0 decrease as the adopted metal content increases. This suggests a metallicity correction to LMC-based distances as given by about -0.27 mag/dex. Such a theoretical correction appears supported by an existing, although weak, correlation between the Cepheid distance and the [O/H] metallicity of galaxies within a given group or cluster, as well as by a similar correlation between the H_0 estimate and the [O/H] metallicity of the galaxies which calibrate the SNIa luminosity. On the contrary, the metallicity correction earlier suggested on empirical grounds seem to be excluded. Eventually we suggest that the average value ~ 67 km/s/Mpc provided by the Key Project team should increase at least up to ~ 69 km/s/Mpc.

Affiliated with

Also associated with

No associations

Rating

Theoretical Models for Classical Cepheids: VII. Metallicity effects on the Cepheid distance scale does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Theoretical Models for Classical Cepheids: VII. Metallicity effects on the Cepheid distance scale, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Theoretical Models for Classical Cepheids: VII. Metallicity effects on the Cepheid distance scale will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-655729