THE CEPHEID PERIOD-LUMINOSITY RELATION (THE LEAVITT LAW) AT MID-INFRARED WAVELENGTHS. IV. CEPHEIDS IN IC 1613

Journal Article · Mon Apr 20 04:00:00 EDT 2009 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/695/2/996; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA)· OSTI ID:21296249

Freedman, Wendy L; Rigby, Jane; Madore, Barry F; Persson, S E; Sturch, Laura; Mager, Violet ^[1]

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1. Observatories of the Carnegie Institution of Washington, 813 Santa Barbara Street, Pasadena, CA 91101 (United States)

We present mid-infrared period-luminosity relations for Cepheids in the Local Group galaxy IC 1613. Using archival Infrared Array Camera (IRAC) imaging data from Spitzer we were able to measure single-epoch magnitudes for five, 7-50 days, Cepheids at 3.6 and 4.5 {mu}m. When fit to the calibrating relations, measured for the Large Magellanic Cloud Cepheids, the data give apparent distance moduli of 24.29 {+-} 0.07 and 24.28 {+-} 0.07 at 3.6 and 4.5 {mu}m, respectively. A multiwavelength fit to previously published BVRIJHK apparent moduli and the two IRAC moduli gives a true distance modulus of 24.27 {+-} 0.02 mag with E(B - V) = 0.08 mag, and a corresponding metric distance of 715 kpc. Given that these results are based on single-phase observations derived from exposures having total integration times of only 1000 s pixel{sup -1}, we suggest that Cepheids out to about 2 Mpc are accessible to Spitzer with modest integration times during its warm mission. We identify the main limiting factor to this method to be crowding/contamination induced by the ubiquitous population of infrared-bright asymptotic giant branch stars.

• OSTI ID: 21296249
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 695; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

99 GENERAL AND MISCELLANEOUS
ASYMPTOTIC SOLUTIONS
CAMERAS
CEPHEIDS
DISTANCE
LUMINOSITY
MAGELLANIC CLOUDS
METRICS
RED SHIFT
WAVELENGTHS