| タイトル | The Carnegie Hubble Program: The Leavitt Law at 3.6 microns and 4.5 microns in the Large Magellanic Cloud |
| 本文（外部サイト） | http://hdl.handle.net/2060/20120002554 |
| 著者（英） | Scowcroft, Victoria; Madore, Barry F.; Persson, S. E.; Freedman, Wendy L.; Seibert, Mark; Monson, Andrew J.; Sturch, Laura; Rigby, Jane R. |
| 著者所属（英） | NASA Goddard Space Flight Center |
| 発行日 | 2011-08-01 |
| 言語 | eng |
| 内容記述 | The Carnegie Hubble Program (CHP) is designed to improve the extragalactic distance scale using data from the post-cryogenic era of Spitzer. The ultimate goal is a determination of the Hubble constant to an accuracy of 2%. This paper is the first in a series on the Cepheid population of the Large Magellanic Cloud, and focuses on the period-luminosity relations (Leavitt laws) that will be used, in conjunction with observations of Milky Way Cepheids, to set the slope and zero-point of the Cepheid distance scale in the mid-infrared. To this end, we have obtained uniformly-sampled light curves for 85 LMC Cepheids, having periods between 6 and 140 days. Period- luminosity and period-color relations are presented in the 3.6 micron and 4.5 micron bands. We demonstrate that the 3.6 micron band is a superb distance indicator. The cyclical variation of the [3.6]-[4.5] color has been measured for the first time. We attribute the amplitude and phase of the color curves to the dissociation and recombination of CO molecules in the Cepheid s atmosphere. The CO affects only the 4.5 micron flux making it a potential metallicity indicator. |
| NASA分類 | Astronomy |
| レポートNO | GSFC.JA.5655.2011 |
| 権利 | Copyright, Distribution as joint owner in the copyright |
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