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

• Published in: The Astrophysical journal Vol. 816; no. 2; pp. 1 - 10
• Main Authors: Scowcroft, Victoria, Freedman, Wendy L., Madore, Barry F., Monson, Andy, Persson, S. E., Rich, Jeff, Seibert, Mark, Rigby, Jane R.
• Format: Journal Article
• Language: English
• Published: Goddard Space Flight Center The American Astronomical Society 10-01-2016; The Astrophysical Journal; IOP Publishing
• Subjects: Astrophysics; ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; Cepheid variables; CEPHEIDS; Clumps; COMPUTERIZED SIMULATION; DISTANCE; Elongation; Galaxies; galaxies: individual (SMC); Indicators; INTERMEDIATE INFRARED RADIATION; MAGELLANIC CLOUDS; Simulation; stars: variables: Cepheids; Streams; VARIABLE STARS
• ISSN: 0004-637X; 1538-4357
• DOI: 10.3847/0004-637X/816/2/49

ABSTRACT Using Spitzer observations of classical Cepheids we have measured the true average distance modulus of the Small Magellanic Cloud (SMC) to be mag (corresponding to 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.