The metallicity dependence of inferred Cepheid distances

Astronomy and Astrophysics – Astrophysics

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

73

Cepheid Variables, Distance, Galaxies, Magellanic Clouds, Metallicity, Correlation, Inference, Populations, Stellar Luminosity, Stellar Magnitude

Scientific paper

I investigate the dependence on metallicity of the apparent distance modulus of a galaxy as inferred from Cepheids. I compare data from Cepheids in three fields in M31 with Cepheids in the Large Magellanic Cloud (LMC), taking account of the high degree of correlations among the BV RI magnitude measurements. I find a significant dependence of apparent distance modulus on metallicity over the range -0.5 less than (Fe/H) less than 0.2. Taking all the available data at face value, I estimate that the distance modulus of a galaxy as inferred from Cepheids should be corrected by an amount delta mu = (0.88 +/- 0.16) delta(Fe/H), where delta(Fe/H) is the difference in metallicity between the galaxy and that of the LMC (where the Cepheids are calibrated). The sign is such that the distances to metal-rich galaxies such as M31 and M81 would be underestimated if the effect were not taken into account. However, there are important systematic uncertainties in this determination. In particular, if the R data are ignored, I find delta mu = (0.56 +/- 0.20) delta(Fe/H). I investigate the possible origins of this discrepancy and the further observations which would be required to resolve it. I discuss the implications for the problem of the determining the Hubble parameter and for the problem of measuring large-scale motions.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

The metallicity dependence of inferred Cepheid distances 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 The metallicity dependence of inferred Cepheid distances, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The metallicity dependence of inferred Cepheid distances will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-884984

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.