The ACS Nearby Galaxy Survey Treasury. III. Cepheids In The Outer Disk Of M81

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Date

2009-06

Authors

McCommas, Les P.
Yoachim, Peter
Williams, Benjamin F.
Dalcanton, Julianne J.
Davis, Matthew R.
Dolphin, Andrew E.

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Volume Title

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Abstract

The ACS Nearby Galaxy Survey Treasury (ANGST) has acquired deep ACS imaging of a field in the outer disk of the large spiral galaxy M81. These data were obtained over a total of 20 Hubble Space Telescope orbits, providing a baseline long enough to reliably identify Cepheid variable stars in the field. Fundamental mode and first overtone types have been distinguished through comparative fits with corresponding Cepheid light curve templates derived from principal component analysis of confirmed Cepheids in the Large Magellanic Cloud (LMC), Small Magellanic Cloud, and Milky Way. A distance modulus of 27.78 +/- 0.05(r) +/- 0.14(s) with a corresponding distance of 3.60 +/- 0.23 Mpc has been calculated from a sample of 11 fundamental mode and two first overtone Cepheids (assuming an LMC distance modulus of mu(LMC) = 18.41 +/- 0.10(r) +/- 0.13(s)).

Department

Astronomy

Description

Keywords

cepheids, galaxies: distances and redshifts, galaxies: individual (m81), gravitational lensing experiment, period-luminosity relations, large-magellanic-cloud, zero-point, classical cepheids, hubble constant, spiral galaxies, color relations, key project, distance, astronomy & astrophysics

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Citation

McCommas, Les P., Peter Yoachim, Benjamin F. Williams, Julianne J. Dalcanton, Matthew R. Davis, and Andrew E. Dolphin. >The ACS Nearby Galaxy Survey Treasury. III. Cepheids in the Outer Disk of M81.> The Astronomical Journal, Vol. 137, No. 6 (Jun., 2009)

URI

http://hdl.handle.net/2152/34338

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