A GALAXY MODEL FROM TWO MICRON ALL SKY SURVEY STAR COUNTS IN THE WHOLE SKY, INCLUDING THE PLANE

We use the star count model of Ortiz & Lepine to perform an unprecedented exploration of the most important Galactic parameters comparing the predicted counts with the Two Micron All Sky Survey observed star counts in the J, H, and K sub(s) bands for a grid of positions covering the whole sky. The comparison is made using a grid of lines of sight given by the HEALPix pixelization scheme. The resulting best-fit values for the parameters are; 2120 + or - 200 pc for the radial scale length and 205 + or - 40 pc for the scale height of the thin disk, with a cental hole of 2070 super(+2000) sub(-800) pc for the same disk, 3050 + or - 500 pc for the radial scale length and 640 + or - 70 pc for the scale height of the thick disk, 400 + or - 100 pc for the cental dimension of the spheroid, 0.0082 + or - 0.0030 for the spheroid to disk density ratio, and 0.57 + or - 0.05 for the oblate spheroid parameter.