COBE Diffuse Infrared Background Experiment Observations of Galactic Reddening and Stellar Populations

April 1994 • 1994ApJ...425L..85A

Authors • Arendt, R. G. • Berriman, G. B. • Boggess, N. • Dwek, E. • Hauser, M. G. • Kelsall, T. • Moseley, S. H. • Murdock, T. L. • Odegard, N. • Silverberg, R. F. • Sodroski, T. J. • Weiland, J. L.

Abstract • This Letter describes the results of an initial study of Galactic extinction and the colors of Galactic stellar populations in the near-IR using the Diffuse Infrared Background Experiment (DIRBE) aboard the Cosmic Background Explorer (COBE) spacecraft. The near-IR reddening observed by DIRBE is consistent with the extinction law tabulated by Rieke & Lebofsky (1985). The distribution of dust and stars in most of the first and fourth quadrants of the Galactic plane (0 deg less than l less than 90 deg, and 270 deg less than l less than 360 deg, respectively) can be modeled as a stellar background source seen through up to approximately 4 mag of extinction at 1.25 micrometers. The unreddened near-IR colors of the Galactic disk are similar to those of late-K and M giants. The Galactic bulge exhibits slightly bluer colors in the 2.2-3.5 micrometers range, as noted by Terndrup et al. (1991). Star-forming regions exhibit colors that indicate the presence of a approximately 900 K continuum produced by hot dust or polycyclic aromatic hydrocarbons (PAHs) contributing at wavelengths as short as 3.5 micrometers.


IPAC Authors


Bruce Berriman

Senior Scientist