The Milky Way, Local Galaxies, and the Infrared Tully‐Fisher Relation

Abstract

Using the near-infrared fluxes of local galaxies derived from Cosmic Background Explorer (COBE)/ Diffuse Infrared Background Experiment (DIRBE)COBE data sets were devloped by the NASA Goddard Space Flight Center under the guidance of the COBE Science Working Group and were provided by the National Space Science Data Center (NSSDC). J- (1.25 μm) K- (2.2 μm), and L-band (3.5 μm) maps and published Cepheid distances, we construct Tully-Fisher (TF) diagrams for nearby galaxies. The measured dispersions in these luminosity-line width diagrams are remarkably small: σJ = 0.09 mag, σK = 0.13 mag, and σL = 0.20 mag. These dispersions include contributions from the intrinsic TF relation scatter and the errors in estimated galaxy distances, fluxes, inclination angles, extinction corrections, and circular speeds. For the J and K bands, Monte Carlo simulations give a 95% confidence interval upper limit on the true scatter in the TF diagram of σJ ≤ 0.35 and σK ≤ 0.45.