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Title: THE CARNEGIE HUBBLE PROGRAM: THE INFRARED LEAVITT LAW IN IC 1613

Journal Article · · Astrophysical Journal
; ; ; ; ;  [1];  [2];  [3]
  1. Observatories of the Carnegie Institution for Science, 813 Santa Barbara Street, Pasadena, CA 91101 (United States)
  2. Observational Cosmology Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)
  3. Caltech Optical Observatories, Division of Physics, Mathematics and Astronomy, Mail Stop 301-17, California Institute of Technology, Pasadena, CA 91125 (United States)

We have observed the dwarf galaxy IC 1613, at multiple epochs in the mid-infrared using Spitzer and contemporaneously in the near-infrared using the new FourStar near-infrared camera on Magellan. We have constructed Cepheid period-luminosity relations in the J, H, K{sub s} , [3.6] and [4.5] bands and have used the run of their apparent distance moduli as a function of wavelength to derive the line-of-sight reddening and distance to IC 1613. Using a nine-band fit, we find E(B - V) = 0.05 {+-} 0.01 mag and an extinction-corrected distance modulus of {mu}{sub 0} = 24.29 {+-} 0.03{sub statistical} {+-} 0.03{sub systematic} mag. By comparing our multi-band and [3.6] distance moduli to results from the tip of the red giant branch and red clump distance indicators, we find that metallicity has no measurable effect on Cepheid distances at 3.6 {mu}m in the metallicity range -1.0 {<=} [Fe/H] {<=} 0.2, hence derivations of the Hubble constant at this wavelength require no correction for metallicity.

OSTI ID:
22131008
Journal Information:
Astrophysical Journal, Vol. 773, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
Country of Publication:
United States
Language:
English