Saved in:
Bibliographic Details
Main Authors: Zhang, Chunyi, Wang, Junfeng, Cao, Tian-Wen
Format: Preprint
Published: 2025
Subjects:
Online Access:https://arxiv.org/abs/2501.01613
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866917883221639168
author Zhang, Chunyi
Wang, Junfeng
Cao, Tian-Wen
author_facet Zhang, Chunyi
Wang, Junfeng
Cao, Tian-Wen
contents The cold and hot interstellar medium (ISM) in star forming galaxies resembles the reservoir for star formation and associated heating by stellar winds and explosions during stellar evolution, respectively. We utilize data from deep $Chandra$ observations and archival millimeter surveys to study the interconnection between these two phases and the relation to star formation activities in M51 on kiloparsec scales. A sharp radial decrease is present in the hot gas surface brightness profile within the inner 2 kpc of M51. The ratio between the total infrared luminosity ($L_{\rm IR}$) and the hot gas luminosity ($L_{\rm 0.5 - 2\,keV}^{\rm gas}$) shows a positive correlation with the galactic radius in the central region. For the entire galaxy, a twofold correlation is revealed in the $L_{\rm 0.5 - 2\,keV}^{\rm gas}$${-}$$L_{\rm IR}$ diagram, where $L_{\rm 0.5 - 2\,keV}^{\rm gas}$ sharply increases with $L_{\rm IR}$ in the center but varies more slowly in the disk. The best fit gives a steep relation of ${\rm log}(L_{\rm 0.5-2\,keV}^{\rm gas} /{\rm erg\,s^{-1}})=1.82\,{\rm log}(L_{\rm IR} /{L_{\rm \odot}})+22.26$ for the center of M51. The similar twofold correlations are also found in the $L_{\rm 0.5 - 2\,keV}^{\rm gas}$${-}$molecular line luminosity ($L^\prime_{\rm gas}$) relations for the four molecular emission lines CO(1-0), CO(2-1), HCN(1-0), and HCO$^+$(1-0). We demonstrate that the core-collapse supernovae (SNe) are the primary source of energy for heating gas in the galactic center of M51, leading to the observed steep $L_{\rm 0.5 - 2\,keV}^{\rm gas}$${-}$$L_{\rm IR}$ and $L_{\rm 0.5 - 2\,keV}^{\rm gas}$${-}$$L^\prime_{\rm gas}$ relations, as their X-ray radiation efficiencies ($η$ $\equiv$ $L_{\rm 0.5 - 2\,keV}^{\rm gas}$/$\dot{E}_\mathrm{SN}$) increase with the star formation rate surface densities, where $\dot{E}_\mathrm{SN}$ is the SN mechanical energy input rate.
format Preprint
id arxiv_https___arxiv_org_abs_2501_01613
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Fire and Ice in the Whirlpool: Spatially Resolved Scaling Relations between X-ray Emitting Hot Gas and Cold Molecular Gas in M51
Zhang, Chunyi
Wang, Junfeng
Cao, Tian-Wen
Astrophysics of Galaxies
The cold and hot interstellar medium (ISM) in star forming galaxies resembles the reservoir for star formation and associated heating by stellar winds and explosions during stellar evolution, respectively. We utilize data from deep $Chandra$ observations and archival millimeter surveys to study the interconnection between these two phases and the relation to star formation activities in M51 on kiloparsec scales. A sharp radial decrease is present in the hot gas surface brightness profile within the inner 2 kpc of M51. The ratio between the total infrared luminosity ($L_{\rm IR}$) and the hot gas luminosity ($L_{\rm 0.5 - 2\,keV}^{\rm gas}$) shows a positive correlation with the galactic radius in the central region. For the entire galaxy, a twofold correlation is revealed in the $L_{\rm 0.5 - 2\,keV}^{\rm gas}$${-}$$L_{\rm IR}$ diagram, where $L_{\rm 0.5 - 2\,keV}^{\rm gas}$ sharply increases with $L_{\rm IR}$ in the center but varies more slowly in the disk. The best fit gives a steep relation of ${\rm log}(L_{\rm 0.5-2\,keV}^{\rm gas} /{\rm erg\,s^{-1}})=1.82\,{\rm log}(L_{\rm IR} /{L_{\rm \odot}})+22.26$ for the center of M51. The similar twofold correlations are also found in the $L_{\rm 0.5 - 2\,keV}^{\rm gas}$${-}$molecular line luminosity ($L^\prime_{\rm gas}$) relations for the four molecular emission lines CO(1-0), CO(2-1), HCN(1-0), and HCO$^+$(1-0). We demonstrate that the core-collapse supernovae (SNe) are the primary source of energy for heating gas in the galactic center of M51, leading to the observed steep $L_{\rm 0.5 - 2\,keV}^{\rm gas}$${-}$$L_{\rm IR}$ and $L_{\rm 0.5 - 2\,keV}^{\rm gas}$${-}$$L^\prime_{\rm gas}$ relations, as their X-ray radiation efficiencies ($η$ $\equiv$ $L_{\rm 0.5 - 2\,keV}^{\rm gas}$/$\dot{E}_\mathrm{SN}$) increase with the star formation rate surface densities, where $\dot{E}_\mathrm{SN}$ is the SN mechanical energy input rate.
title Fire and Ice in the Whirlpool: Spatially Resolved Scaling Relations between X-ray Emitting Hot Gas and Cold Molecular Gas in M51
topic Astrophysics of Galaxies
url https://arxiv.org/abs/2501.01613