Warp of the Galactic Disk as seen in Mid Infrared from Midcourse Space Experiment

Abstract

The nature of the warp structure in the distribution of stellar as well as warm interstellar dust (WISD) components in the Galactic disk has been investigated using respective mid infrared emissions. Such a study with high angular resolution has only recently become possible with the advent of Galactic plane survey in four major bands (8, 12, 14 & 21 µm) by the Midcourse Space Experiment (MSX). The MSX Point Source Catalog as well as the panoramic images have been used here. Various measures representing the location of the mid-plane for the stellar and WISD components have been extracted. The resulting mid-plane latitude versus longitude data have been fitted well with a simple sinusoidal function to look for a warp signature(WS). The WS has been clearly detected in all the four bands for both the stellar as well as the WISD components with similar phases but amplitudes ranging from 0.2 degree - 0.5 degree in latitude. Our results have been compared with those from other studies of similar measures of WS.