The HI Distribution Observed toward a Halo Region of the Milky Way

TL;DR

This study maps the distribution of neutral hydrogen in a specific halo region of the Milky Way, revealing the absence of detectable HI emission above certain latitudes, and estimates column densities in the observed regions.

Contribution

First detailed HI distribution map of a Milky Way halo region with spectral sensitivity, providing new insights into the gas extent and density in the Galactic halo.

Findings

No HI emission detected above 2σ at latitudes > 46°

Estimated HI column densities range from 3 to 11×10^{20} cm^{-2}

Map sensitivity of approximately 2 K

Abstract

We use observations of the neutral atomic hydrogen (HI) 21-cm emission line to study the spatial distribution of the HI gas in a 80$\degree\times~$90$\degree$ region of the Galaxy halo. The HI column densities in the range of \mbox{3--11$\times$10$^{20}$ cm$^{-2}$} have been estimated for some of the studied regions. In our map---obtained with a spectral sensitivity of $\sim$2 K---we do not detect any HI 21-cm emission line {above 2$\sigma$} at Galactic latitudes higher than $\sim${46}$\degree$. {This report summarizes our contribution presented at the conference on the origin and evolution of barionic Galaxy halos}.