# ALMA Observations of the HD~110058 debris disk

**Authors:** Antonio S. Hales, SebastiÁn Marino, Patrick D. Sheehan, Silvio Ulloa, SebastiÁn PÉrez, Luca MatrÀ, Quentin Kral, Mark Wyatt, William Dent, John Carpenter  
**arXiv:** [2210.12275](https://arxiv.org/abs/2210.12275)  
**Date:** 2022-10-21  
**Summary page:** https://www.summarizepaper.com/en/arxiv-id/2210.12275v1/

## Key points

- The Atacama Large Millimeter Array (ALMA) observed the young, gas-rich debris disk around HD110058
- This is the smallest debris disk around stars of similar luminosity observed by ALMA
- The disk was detected in the 0.85 and 1.3 mm continuum, as well as in the J=2-1 and J=3-2 transitions of $^{12}$CO and $^{13}$CO
- Radiative transfer modeling was used to constrain the physical properties of dust and gas disks
- Dust density peaks at around 31 AU with a smooth outer edge extending out to approximately 70 AU
- CO gas distribution is more compact than the dust which could be due to a low viscosity and a higher gas release rate at small radii
- HD~110058's CO gas mass and distribution are consistent with a secondary origin scenario according to simulations of the gas evolution taking into account CO photodissociation, shielding, and viscous evolution.
- The debris disk is very close to edge-on with an estimated true full width half maximum of (∆rin + ∆rout)/2 = 15 AU

## Summary

The Atacama Large Millimeter Array (ALMA) has been used to observe the young, gas-rich debris disk around HD110058 at a resolution of 0.3-0.6 arcseconds. The observations have revealed that this is the smallest debris disk around stars of similar luminosity observed by ALMA. The disk has been detected in the 0.85 and 1.3 mm continuum, as well as in the J=2-1 and J=3-2 transitions of $^{12}$CO and $^{13}$CO, with the dust and gas distributions being resolved. Radiative transfer modeling has been used to constrain the physical properties of dust and gas disks, revealing that the dust density peaks at around 31 AU with a smooth outer edge extending out to approximately 70 AU. Interestingly, the dust emission is marginally resolved along the minor axis indicating that it is vertically thick if truly close to edge-on with an aspect ratio between 0.13 and 0.28. The CO gas distribution is more compact than the dust which could be due to a low viscosity and a higher gas release rate at small radii. Using simulations of the gas evolution taking into account CO photodissociation, shielding, and viscous evolution, it has been found that HD~110058's CO gas mass and distribution are consistent with a secondary origin scenario. The ALMA observations confirm that HD110058's debris disk is very close to edge-on as shown previously in scattered light images with an estimated true full width half maximum of (∆rin + ∆rout)/2 = 15 AU .