# MINDS. The detection of $^{13}$CO$_{2}$ with JWST-MIRI indicates abundant CO$_{2}$ in a protoplanetary disk

**Authors:** Sierra L. Grant, Ewine F. van Dishoeck, Benoît Tabone, Danny Gasman, Thomas Henning, Inga Kamp, Manuel Güdel, Pierre-Olivier Lagage, Giulio Bettoni, Giulia Perotti, Valentin Christiaens, Matthias Samland, Aditya M. Arabhavi, Ioannis Argyriou, Alain Abergel, Olivier Absil, David Barrado, Anthony Boccaletti, Jeroen Bouwman, Alessio Caratti o Garatti  
**arXiv:** [2212.08047](https://arxiv.org/abs/2212.08047)  
**Date:** 2022-12-15  
**Summary page:** https://www.summarizepaper.com/en/paper/2212.08047v1/

## Key points

- The MIRI mid-infrared spectrograph (MRS) on board the James Webb Space Telescope (JWST) detected $^{13}$CO$_{2}$ in a protoplanetary disk for the first time.
- The observation was part of the MIRI Mid-Infrared Disk Survey (MINDS) GTO program, which revealed emission from several molecules, including $^{12}$CO$_{2}$, $^{13}$CO$_{2}$, H$_{2}$O, HCN, and C$_{2}$H$_{2}$.
- High spectral resolution and signal-to-noise ratio provided by JWST-MIRI MRS allowed for identification of these species and determination of their column densities and temperatures.
- The $Q$-branches of these molecules are particularly sensitive to temperature and column density, providing insight into the chemical and physical conditions in the inner few au of the GW Lup disk.
- Optically thick $^{12}\rm{CO_2}, found at a temperature of $\sim500\ \rm{K},$ suggests that this molecule is abundant in the disk.
- Optically thinner $^{13}CO_2$, which traces a larger emitting area than $^{12}\rm{CO_2},$ is found deeper into the disk based on its lower temperature of $\sim200\ \rm{K}.$
- The derived ratio of CO${_2}\over{\rm{H_2O}}\ (N_{\rm{CO_2}}/N_{\rm{H_2O}})$ in GW Lup is relatively high compared to other targets determined from Spitzer-IRS data.
- This abundance ratio may be due to an inner cavity in the gas and dust with a radius between the H${_2}\rm{O}\ and\ CO_ { 2 } snowlines and/or a dust trap at this location keeping water-rich icy grains from passing beyond the water snowline.
- These findings demonstrate JWST's unique ability to probe inner disk structures and chemistry through weak molecular features that were previously unseen.
- The MIRI MRS observations provide valuable insights into protoplanetary disks' chemical composition and physical conditions, shedding light on planetary systems' formation and evolution.

## Summary

The MIRI mid-infrared spectrograph (MRS) on board the James Webb Space Telescope (JWST) has enabled the detection of $^{13}$CO$_{2}$ in a protoplanetary disk for the first time. The disk around the low-mass T Tauri star GW Lup was observed as part of the MIRI Mid-Infrared Disk Survey (MINDS) GTO program, revealing emission from $^{12}$CO$_{2}$, $^{13}$CO$_{2}$, H$_{2}$O, HCN, and C$_{2}$H$_{2}$. The high spectral resolution and signal-to-noise ratio provided by JWST-MIRI MRS allowed for identification of these species and determination of their column densities and temperatures. The $Q$-branches of these molecules are particularly sensitive to temperature and column density, providing insight into the chemical and physical conditions in the inner few au of the GW Lup disk. The strong emission from optically thick $^{12}$CO$_{2}$, found at a temperature of $\sim500\ \rm{K}$, suggests that this molecule is abundant in the disk. On the other hand, optically thinner $^{13}CO_2$, which traces a larger emitting area than $^{12}\rm{CO_2}, is found deeper into the disk based on its lower temperature of $\sim200\ \rm{K}. The derived ratio of CO${_2}\over{\rm{H_2O}}\ (N_{\rm{CO_2}}/N_{\rm{H_2O}}) \ in \ GW \ Lup \ is \ relatively \ high \ compared \ to \ other targets determined from Spitzer-IRS data. This abundance ratio may be due to an inner cavity in the gas and dust with a radius between the H${_2}\rm{O}\ and\ CO_ { 2 } snowlines and/or a dust trap at this location keeping water-rich icy grains from passing beyond the water snowline. Overall, these findings demonstrate JWST's unique ability to probe inner disk structures and chemistry through weak molecular features that were previously unseen. The MIRI MRS observations provide valuable insights into protoplanetary disks' chemical composition and physical conditions, shedding light on planetary systems' formation and evolution.