JWST and ground data show DQ Tau molecular gas fades after accretion bursts

Astronomers monitored the young eccentric binary DQ Tau with seven instruments from the ground and space over 40 days. The system is a T Tauri binary with pulsed accretion bursts regulated by its roughly 16-day orbital period.

The study uses nine JWST-MIRI and nine IRTF-iSHELL epochs covering three sequential accretion bursts, in which accretion luminosity pulses rose by factors of about 9 to 80. It adds new measurements of line broadening in CO from iSHELL and H2O from MIRI, used to estimate Keplerian radii and their variability alongside line luminosity.

The molecular emission did not react like HI and the 5-micron continuum with each burst. Line luminosity and width of all hot molecular gas tracers decreased over about 30 to 35 days, consistent with an emitting region cooling and losing mass as it recedes to larger radii within the 0.2 to 0.4 au inner cavity perturbed by the binary.

The authors conclude the infrared molecular spectrum is affected more by disk dynamics than by chemical changes triggered by variable accretion. The paper was submitted to arXiv on 5 November.

Sourcearxiv.org