Uncertainties in the interstellar extinction curve and the Cepheid distance to M101

David M. Nataf*

*Corresponding author for this work

    Research output: Contribution to journalArticlepeer-review

    15 Citations (Scopus)

    Abstract

    I revisit the Cepheid-distance determination to the nearby spiral galaxy M101 (Pinwheel Galaxy) of Shappee & Stanek, in light of several recent investigations questioning the shape of the interstellar extinction curve at λ ≈ 8000 Å (i.e. the I band). I find that the relatively steep extinction ratio AI/E(V - I) = 1.1450 from Fitzpatrick & Massa is slightly favoured relative to AI/E(V - I) = 1.2899 from Fitzpatrick and significantly favoured relative the historically canonical value of AI/E(V - I) = 1.4695, from Cardelli et al. The steeper extinction curves, with lower values of AI/E(V - I), yield fits with reduced scatter, metallicity dependences to the dereddened Cepheid luminosities that are closer to values inferred in the Local Group, and that are less sensitive to the choice of reddening cut imposed in the sample selection. The increase in distance modulus to M101 when using the preferred extinction curve is Δμ~0.06 mag, resulting in the estimate of the distance modulus to M101 relative to the LMC is ΔμLMC ≈ 10.72 ± 0.03 (stat). The best-fitting metallicity dependence is dMI /d[O/H] ≈ (-0.38 ± 0.14 (stat)) mag dex-1.

    Original languageEnglish
    Pages (from-to)1171-1176
    Number of pages6
    JournalMonthly Notices of the Royal Astronomical Society
    Volume449
    Issue number2
    DOIs
    Publication statusPublished - 11 May 2015

    Fingerprint

    Dive into the research topics of 'Uncertainties in the interstellar extinction curve and the Cepheid distance to M101'. Together they form a unique fingerprint.

    Cite this