THE CARNEGIE HUBBLE PROGRAM

Journal Article · Thu Dec 15 04:00:00 EST 2011 · Astronomical Journal (New York, N.Y. Online)

DOI:https://doi.org/10.1088/0004-6256/142/6/192· OSTI ID:22034334

Freedman, Wendy L; Madore, Barry F; Scowcroft, Victoria; Monson, Andy; Persson, S E; Seibert, Mark ^[1]; Rigby, Jane R ^[2]; Sturch, Laura ^[3]; Stetson, Peter ^[4]

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1. Observatories of the Carnegie Institution of Washington, 813 Santa Barbara St., Pasadena, CA 91101 (United States)
2. Observational Cosmology Lab, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)
3. Department of Astronomy, Boston University, 725 Commonwealth Avenue, Boston, MA 02215 (United States)
4. Dominion Astrophysical Observatory, National Research Council of Canada, Herzberg Institute of Astrophysics, 5071 West Saanich Road, Victoria, BC V9E 2E7 (Canada)

We present an overview of and preliminary results from an ongoing comprehensive program that has a goal of determining the Hubble constant to a systematic accuracy of {+-}2%. As part of this program, we are currently obtaining 3.6 {mu}m data using the Infrared Array Camera on Spitzer, and the program is designed to include James Webb Space Telescope in the future. We demonstrate that the mid-infrared period-luminosity relation for Cepheids at 3.6 {mu}m is the most accurate means of measuring Cepheid distances to date. At 3.6 {mu}m, it is possible to minimize the known remaining systematic uncertainties in the Cepheid extragalactic distance scale. We discuss the advantages of 3.6 {mu}m observations in minimizing systematic effects in the Cepheid calibration of H{sub 0} including the absolute zero point, extinction corrections, and the effects of metallicity on the colors and magnitudes of Cepheids. We undertake three independent tests of the sensitivity of the mid-IR Cepheid Leavitt Law to metallicity, which when combined will allow a robust constraint on the effect. Finally, we provide a new mid-IR Tully-Fisher relation for spiral galaxies.

• OSTI ID: 22034334
• Journal Information: Astronomical Journal (New York, N.Y. Online), Journal Name: Astronomical Journal (New York, N.Y. Online) Journal Issue: 6 Vol. 142; ISSN 1538-3881
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ACCURACY
ASTRONOMY
ASTROPHYSICS
CALIBRATION
CAMERAS
CEPHEIDS
CORRECTIONS
DISTANCE
GALAXIES
INTERMEDIATE INFRARED RADIATION
LUMINOSITY
RED SHIFT
SENSITIVITY
TELESCOPES