The Araucaria Project: The distance to the Local Group galaxy WLM from near-infrared photometry of Cepheid variables

Gieren, W.; Pietrzynski G.; Szewczyk O.; Soszynski I.; Bresolin, F; Kudritzki, RP; Urbaneja, MA; Storm, J; Minniti, D

Abstract

We have obtained deep images in the near-infrared J and K filters for several fields in the Local Group galaxy WLM. We report intensity mean magnitudes for 31 Cepheids located in these fields, which we previously discovered in a wide-field optical imaging survey of WLM. The data define tight period-luminosity relations in both near-infrared bands, which we use to derive the total reddening of the Cepheids in WLM and the true distance modulus of the galaxy from a multiwavelength analysis of the reddened distance moduli in the VIJK bands. From this, we obtain. the values E(B -V) = 0.082 ± 0.02 and (m - M)0 = 24.924 ± 0.042 mag, with a systematic uncertainty in the distance of about ±3%. This Cepheid distance agrees extremely well with the distance of WLM determined from the I-band tip of the red giant branch (TRGB) method by ourselves and others. Most of the reddening of the Cepheids in WLM (0.06 mag) is produced inside the galaxy, demonstrating again the need for an accurate determination of the total reddening and/or the use of infrared photometry to derive Cepheid distances which are accurate to 3% or better, even for small irregular galaxies like WLM. © 2008. The American Astronomical Society. All rights reserved.

Más información

Título según WOS: The Araucaria Project: The distance to the Local Group galaxy WLM from near-infrared photometry of Cepheid variables
Título según SCOPUS: The araucaria project: The distance to the local group galaxy WLM from near-infrared photometry of cepheid variables
Título de la Revista: ASTROPHYSICAL JOURNAL
Volumen: 683
Número: 2
Editorial: IOP PUBLISHING LTD
Fecha de publicación: 2008
Página de inicio: 611
Página final: 619
Idioma: English
URL: http://stacks.iop.org/0004-637X/683/i=2/a=611
DOI:

10.1086/589994

Notas: ISI, SCOPUS