Period-luminosity relations of type II Cepheids in the Magellanic Clouds

Дата и время публикации : 2010-12-01T05:40:52Z

Авторы публикации и институты :
Noriyuki Matsunaga (Kiso Observatory, University of Tokyo)
Michael W. Feast (South African Astronomical Observatory, University of Cape Town)
Igor Soszynski (Warsaw University)

Ссылка на журнал-издание: Ссылка на журнал-издание не найдена
Коментарии к cтатье: 12 pages, 10 figures and 6 tables, accepted for publication in MNRAS
Первичная категория: astro-ph.SR

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

Краткий обзор статьи: Period-luminosity relations (PLRs) of type II Cepheids (T2Cs) in the Small Magellanic Cloud are derived based on OGLE-III, IRSF/SIRIUS and other data, and these are compared with results for the Large Magellanic Cloud and Galactic globular clusters. Evidence is found for a change of the PLR slopes from system to system. Treating the longer period T2Cs (W Vir stars) separately gives an SMC-LMC modulus difference of 0.39+-0.05 mag without any metallicity corrections being applied. This agrees well with the difference in moduli based on different distance indicators, in particular the PLRs of classical Cepheids. The shorter period T2Cs (BL Her stars) give a smaller SMC-LMC difference suggesting that their absolute magnitudes might be affected either by metallicity or by age effects. It is shown that the frequency distribution of T2C periods also changes from system to system.

Category: Physics