The Carnegie Hubble Program: The Infrared Leavitt Law in IC 1613

Дата и время публикации : 2013-06-24T22:53:00Z

Авторы публикации и институты :
Victoria Scowcroft
Wendy L. Freedman
Barry F. Madore
Andrew J. Monson
S. E. Persson
Mark Seibert
Jane R. Rigby
Jason Melbourne

Ссылка на журнал-издание: Ссылка на журнал-издание не найдена
Коментарии к cтатье: 33 pages, 8 figures. Accepted for publication in ApJ
Первичная категория: astro-ph.CO

Все категории : astro-ph.CO, astro-ph.GA

Краткий обзор статьи: 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-IR camera on Magellan. We have constructed Cepheid period–luminosity relations in the J, H, K_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 IC1613. Using a nine–band fit, we find E(B-V) = 0.05 +- 0.01 mag and an extinction–corrected distance modulus of mu_{0} = 24.29 +- 0.03_{statistical} +- 0.03_{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 microns in the metallicity range -1.0 < [Fe/H] < 0.2, hence derivations of the Hubble constant at this wavelength require no correction for metallicity.

Category: Physics