The cepheid period-luminosity relation (the leavitt law) at mid-infrared wavelengths. III. cepheids in NGC 6822

Barry F. Madore, Jane Rigby, Wendy L. Freedman, S. E. Persson, Laura Sturch, Violet Mager

Research output: Contribution to journalArticle

8 Scopus citations

Abstract

We present the first application of mid-infrared period-luminosity relations to the determination of a Cepheid distance beyond the Magellanic Clouds. Using archival IRAC imaging data on NGC 6822 from Spitzer we were able to measure single-epoch magnitudes for 16 long-period (10-100 day) Cepheids at 3.6 μm, 14 at 4.5 μm, 10 at 5.8 μm, and four at 8.0 μm. The measured slopes and the observed scatter both conform to the relations previously measured for the Large Magellanic Cloud Cepheids, and fitting to those relations gives apparent distance moduli of μ3.6 = 23.57 ± 0.06, μ4.5 = 23.55 ± 0.07, μ5.8 = 23.60 ± 0.09, and μ8.0 = 23.51 ± 0.08 mag. A multiwavelength fit to the new IRAC moduli, and previously published BVRIJHK moduli, allows for a final correction for interstellar reddening and gives a true distance modulus of 23.49 ± 0.03 mag with E(B-V) = 0.26 mag, corresponding to a metric distance of 500 ± 8 kpc.

Original languageEnglish (US)
Pages (from-to)936-939
Number of pages4
JournalAstrophysical Journal
Volume693
Issue number1
DOIs
StatePublished - Mar 1 2009

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

Fingerprint Dive into the research topics of 'The cepheid period-luminosity relation (the leavitt law) at mid-infrared wavelengths. III. cepheids in NGC 6822'. Together they form a unique fingerprint.

  • Cite this