A COBE Model of the Galactic Bar and Disk
Abstract
A model of the bar and old stellar disk of the Galaxy has been derived from the survey of the Diffuse Infrared Background Experiment (DIRBE) of the Cosmic Background Explorer at wavelengths of 1.25, 2.2, 3.5, and 4.9 μm. It agrees very well with the data, except in directions in which the near-infrared optical depth is high. Among the conclusions drawn from the model is that the Sun is located approximately 16.5 pc above the midpoint of the Galactic plane. The disk has an outer edge 4 kpc from the Sun and is warped like the H I layer. It has a central hole roughly the diameter of the inner edge of the 3 kpc molecular cloud ring, and within that hole lies a bright, strong, ``early-type'' bar, tilted approximately 14° from the Sun-Galactic center line. The model has 47 free parameters. The model is discussed in detail, and contour plots and images of the residuals are presented.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- January 1998
- DOI:
- 10.1086/305065
- arXiv:
- arXiv:astro-ph/9707340
- Bibcode:
- 1998ApJ...492..495F
- Keywords:
-
- COSMOLOGY: DIFFUSE RADIATION;
- GALAXY: FUNDAMENTAL PARAMETERS;
- GALAXIES: PHOTOMETRY;
- GALAXY: STRUCTURE;
- INFRARED: GALAXIES;
- Cosmology: Diffuse Radiation;
- Galaxies: Photometry;
- Galaxy: Fundamental Parameters;
- Galaxy: Structure;
- Infrared: Galaxies;
- Astrophysics
- E-Print:
- 30 pages, LaTeX, with 15 figures, 3 JPG and 12 GIF. Accepted by ApJ. Corrected a factor-of-2 error in total luminosity and replaced 2 corrupted JPEG files. Relevant images of the Galactic J-K and K-L colors can be found at http://www.gsfc.nasa.gov/astro/cobe/dirbe_image.html
