A study of the massive star forming region M8 using Spitzer IRAC images
  Spitzer IRAC images (3.6, 4.5, 5.8 and 8.0$\mu$m) and photometry of the star
forming region M8 are presented. IRAC photometry reveals ongoing star formation
in the M8 complex, with 64 Class 0/I and 168 Class II sources identified in
several locations in the vicinity of sub-mm gas cores/clumps. Nearly 60% of
these YSOs occur in about 7 small clusters. The spatial surface density of the
clustered YSOs is determined to be about 10-20 YSOs/pc$^{2}$. Fresh star
formation by the process of "collect and collapse" might have been triggered by
the expanding HII regions and winds from massive stars. IRAC ratio images are
generated and studied in order to identify possible diagnostic emission regions
in M8. The image of 4.5$\mu$m/8.0$\mu$m reveals Br$\alpha$ counterpart of the
optical Hourglass HII region, while the ratio 8.0$\mu$m/4.5$\mu$m indicates PAH
emission in a cavity-like structure to the east of the Hourglass. The ratio
maps of 3.6$\mu$m/4.5$\mu$m, 5.8$\mu$m/4.5$\mu$m and 8.0$\mu$m/4.5$\mu$m seem
to identify PAH emission regions in the sharp ridges and filamentary structures
seen East to West and NE to SW in M8 complex.
