MINDS. JWST-MIRI reveals a peculiar CO$_2$-rich chemistry in the drift-dominated disk CX Tau

Marissa Vlasblom; Milou Temmink; Sierra L. Grant; Nicolas Kurtovic; Andrew D. Sellek; Ewine F. van Dishoeck; Manuel GÃ¼del; Thomas Henning; Pierre-Olivier Lagage; David Barrado; Alessio Caratti o Garatti; Adrian M. Glauser; Inga Kamp; Fred Lahuis; GÃ¶ran Olofsson; Aditya M. Arabhavi; Valentin Christiaens; Danny Gasman; Hyerin Jang; Maria Morales-CalderÃ³n; Giulia Perotti; Kamber Schwarz; BenoÃ®t Tabone

doi:10.1051/0004-6361/202450863

paper

MINDS. JWST-MIRI reveals a peculiar CO $_{2}$ -rich chemistry in the drift-dominated disk CX Tau

arXiv:2412.12715 · doi:10.1051/0004-6361/202450863

Abstract

Radial drift of icy pebbles can have a large impact on the chemistry of the inner regions of protoplanetary disks. Compact dust disks ( $≲$ 50 au) are suggested to have a higher (cold) H $_{2}$ O flux than more extended disks, likely due to efficient radial drift bringing H $_{2}$ O-rich material to the inner disk, where it can be observed with JWST. We present JWST MIRI/MRS observations of the disk CX Tau taken as a part of the Mid-INfrared Disk Survey (MINDS) GTO program, a prime example of a drift-dominated disk. This compact disk seems peculiar: the source possesses a bright CO $_{2}$ feature instead of the bright H $_{2}$ O expected based on its efficient radial drift. We aim to provide an explanation for this finding. We detect molecular emission from H $_{2}$ O, $^{12}$ CO $_{2}$ , $^{13}$ CO $_{2}$ , C $_{2}$ H $_{2}$ , HCN, and OH in this disk, and even demonstrate a potential detection of CO $^{18}$ O. Analysis of the $^{12}$ CO $_{2}$ and $^{13}$ CO $_{2}$ emission shows the former to be tracing a temperature of $\sim$ 450 K, whereas the $^{13}$ CO $_{2}$ traces a significantly colder temperature ( $\sim$ 200 K). H $_{2}$ O is also securely detected both at shorter and longer wavelengths, tracing a similar temperature of $\sim$ 500-600 K as the CO $_{2}$ emission. We also find evidence for a colder, $\sim$ 200 K H $_{2}$ O component at longer wavelengths, which is in line with this disk having strong radial drift. The cold $^{13}$ CO $_{2}$ and H $_{2}$ O emission indicate that radial drift of ices likely plays an important role in setting the chemistry of the inner disk of CX Tau. Potentially, the H $_{2}$ O-rich gas has already advected onto the central star, which is now followed by an enhancement of comparatively CO $_{2}$ -rich gas reaching the inner disk, explaining the enhancement of CO $_{2}$ emission in CX Tau. The comparatively weaker H $_{2}$ O emission can be explained by the source's low accretion luminosity. (abridged)

23 pages, 17 figures, accepted for publication in Astronomy & Astrophysics

MINDS. JWST-MIRI reveals a peculiar CO2​-rich chemistry in the drift-dominated disk CX Tau

Abstract

MINDS. JWST-MIRI reveals a peculiar CO $_{2}$ -rich chemistry in the drift-dominated disk CX Tau