H I Kinematics and the E(B-V)/N(H I) ratio
Fuente:
arXiv
Saved in:
| Main Author: | |
|---|---|
| Format: | Preprint |
| Published: |
2024
|
| Subjects: | |
| Online Access: | |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866914939893972992 |
|---|---|
| author | Liszt, Harvey |
| author_facet | Liszt, Harvey |
| contents | The $λ21$cm H I emission that is used to trace the gas to dust ratio at high Galactic latitudes has contributions from material beyond the Milky Way disk, with uncertain and likely sub-Solar metallicity and dust content. These contributions can be isolated kinematically and their presence is clear for sightlines with small mean reddening $<$E(B-V)$>$ $\la$ 0.03 mag, which have mean ratios $<$N(H I)$>$/$<$E(B-V)$>$ that are 20-50\% above the high latitude Galactic average $<$N(H I)$>/<$E(B-V)$>=8.3\times10^{21}$cm$^{-2}$mag$^{-1}$. By mapping N(H I) and E(B-V) across H I High Velocity Cloud complexes and the Magellanic Clouds we show that the reddening of this kinematically-isolated gas is on average five times smaller per H I than the high latitude average. However, the aggregate contribution of this gas is small and $<$N(H I)$>/<$E(B-V)$>=8.3\times10^{21}$cm$^{-2}$mag$^{-1}$ is the appropriate value for Galactic gas seen at high latitude using the H I and reddening measures employed here and in our previous work. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2409_03869 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | H I Kinematics and the E(B-V)/N(H I) ratio Liszt, Harvey Astrophysics of Galaxies The $λ21$cm H I emission that is used to trace the gas to dust ratio at high Galactic latitudes has contributions from material beyond the Milky Way disk, with uncertain and likely sub-Solar metallicity and dust content. These contributions can be isolated kinematically and their presence is clear for sightlines with small mean reddening $<$E(B-V)$>$ $\la$ 0.03 mag, which have mean ratios $<$N(H I)$>$/$<$E(B-V)$>$ that are 20-50\% above the high latitude Galactic average $<$N(H I)$>/<$E(B-V)$>=8.3\times10^{21}$cm$^{-2}$mag$^{-1}$. By mapping N(H I) and E(B-V) across H I High Velocity Cloud complexes and the Magellanic Clouds we show that the reddening of this kinematically-isolated gas is on average five times smaller per H I than the high latitude average. However, the aggregate contribution of this gas is small and $<$N(H I)$>/<$E(B-V)$>=8.3\times10^{21}$cm$^{-2}$mag$^{-1}$ is the appropriate value for Galactic gas seen at high latitude using the H I and reddening measures employed here and in our previous work. |
| title | H I Kinematics and the E(B-V)/N(H I) ratio |
| topic | Astrophysics of Galaxies |
| url | https://arxiv.org/abs/2409.03869 |