Abstract

Study of light extinction in the direction of LN45 was carried out using 2MASS data and the behavior of interstellar matter in this direction was unraveled. A case study on a field in the direction l = 315⁰ and b = -0.76 is presented here. Based on the fitting of "red clump" locus, we find that the extinction per kpc cj = 0.16 mag/kpc makes a good fit up-to the distance of 3 kpc whereas beyond this distance its value increases continuously to a value 0.32 at a distance of 7 kpc. As far as the distribution of material is concerned, this finding indicates that the interstellar (IS) density is higher between 3 to 7 kpc (a region occupied by Scutum-Crux spiral arm) compared to the local region.