The Cepheid Period-Luminosity Relation at Mid-Infrared Wavelengths: II. Second-Epoch LMC Data
| Autor: | Madore, Barry F., Freedman, Wendy L., Rigby, Jane, Persson, S. E., Sturch, Laura, Major, Violet |
|---|---|
| Rok vydání: | 2008 |
| Předmět: | |
| Zdroj: | Astrophys.J.695:988-995,2009 |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1088/0004-637X/695/2/988 |
| Popis: | We present revised and improved mid-infrared Period-Luminosity (PL) relations for Large Magellanic Cloud (LMC) Cepheids based on double-epoch data of 70 Cepheids observed by Spitzer at 3.6, 4.5, 5.8 and 8.0um. The observed scatter at all wavelengths is found to decrease from +/-0.17 mag to +/-0.14 mag, which is fully consistent with the prediction that the total scatter is made up of roughly equal contributions from random sampling of the light curve and nearly-uniform samplings of stars across the instability strip. It is calculated that the Cepheids in this sample have a full amplitude of about 0.4 mag and that their fully-sampled, time-averaged magnitudes should eventually reveal mid-infrared PL relations that each have intrinsic scatter at most at the +/-0.12 mag level, and as low as +/-0.08 mag after correcting for the tilt of the LMC. Comment: 7 pages, 6 figures, 1 data table |
| Databáze: | arXiv |
| Externí odkaz: |
|