THE CARNEGIE HUBBLE PROGRAM: THE DISTANCE AND STRUCTURE OF THE SMC AS REVEALED BY MID-INFRARED OBSERVATIONS OF CEPHEIDS

Journal Article · Sun Jan 10 04:00:00 EST 2016 · Astrophysical Journal

DOI:https://doi.org/10.3847/0004-637X/816/2/49· OSTI ID:22862851

Scowcroft, Victoria; Freedman, Wendy L.; Madore, Barry F.; Monson, Andy; Persson, S. E.; Rich, Jeff; Seibert, Mark ^[1]

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

Using Spitzer observations of classical Cepheids we have measured the true average distance modulus of the Small Magellanic Cloud (SMC) to be 18.96±0.01{sub stat}±0.03{sub sys} mag (corresponding to 62±0.3 kpc), which is 0.48 ± 0.01 mag more distant than the LMC. This is in agreement with previous results from Cepheid observations, as well as with measurements from other indicators such as RR Lyrae stars and the tip of the red giant branch. Utilizing the properties of the mid-infrared Leavitt Law we measured precise distances to individual Cepheids in the SMC, and have confirmed that the galaxy is tilted and elongated such that its eastern side is up to 20 kpc closer than its western side. This is in agreement with the results from red clump stars and dynamical simulations of the Magellanic Clouds and Stream.

• OSTI ID: 22862851
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 816; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
CEPHEIDS
COMPUTERIZED SIMULATION
DISTANCE
INTERMEDIATE INFRARED RADIATION
MAGELLANIC CLOUDS
VARIABLE STARS