# The ISM scaling relations using inner HI and an application of estimating dust mass

**Authors:** Fujia Li, Jing Wang, Fengwei Xu, Xu Kong, Xinkai Chen, Zesen Lin, Shun Wang  
**arXiv:** [2304.04465](https://arxiv.org/abs/2304.04465)  
**Date:** 2023-04-10  
**Summary page:** https://www.summarizepaper.com/en/paper/2304.04465v1/

## Key points

- The study focuses on disk-like galaxies with observations of HI, H2, and dust from the Herschel Reference Survey (HRS).
- Inner gas-to-dust ratio is almost independent of gas-phase metallicity.
- Inner gas mass (HI+H2) shows a tighter relationship with dust mass and monochromatic 500 μm luminosity than the integral gas mass.
- Dust is more closely associated with co-spatial cold gas than overall cold gas.
- Newly calibrated relationship between inner gas mass and dust mass predicts dust masses for disk-dominated galaxies from the xCOLD GASS sample.
- Galactic WISE W3 luminosities show significant dependence on both [NII] luminosity and stellar mass surface density when relating to a given dust mass and star formation rate (SFR).
- Potential limitations in using W3 luminosity as an integral SFR indicator are highlighted.
- The study provides valuable insights into ISM scaling relations using inner HI data and offers new predictions for estimating dust masses in disk-dominated galaxies.

## Summary

In this study, the authors focus on a sample of disk-like galaxies with observations of HI, H2, and dust from the Herschel Reference Survey (HRS). They derive inner HI masses within the optical radius and find that the inner gas-to-dust ratio is almost independent of gas-phase metallicity. They also confirm that the inner gas mass (HI+H2) shows a tighter relationship with dust mass and monochromatic 500 μm luminosity than the integral gas mass. This supports the idea that dust is more closely associated with co-spatial cold gas than overall cold gas. Based on their newly calibrated relationship between inner gas mass and dust mass, they predict dust masses for disk-dominated galaxies from the xCOLD GASS sample. The predicted dust masses show scaling relations consistent with fiducial ones in literature, indicating their robustness. Additionally, they investigate how galactic WISE W3 luminosities relate to a given dust mass and star formation rate (SFR). Their findings suggest significant dependence on both [NII] luminosity and stellar mass surface density; this highlights potential limitations in using W3 luminosity as an integral SFR indicator which is consistent with results from studies targeting star-forming regions in nearby galaxies accurately deriving dust masses based on mapping-mode spectroscopy. Overall, this study provides valuable insights into ISM scaling relations using inner HI data and offers new predictions for estimating dust masses in disk-dominated galaxies. It also emphasizes potential drawbacks when using certain indicators to measure SFRs in galactic systems.