Abstract

Aims. We investigate the spatially resolved (interstellar medium) ISM properties of the local (z = 0.048), infrared-luminous (L-IR = 10(11.87) L-circle dot), late-stage galaxy merger IRAS F01364-1042. We combined multiwavelength IFU observations from JWST/MIRI-MRS, ALMA, and Keck/KCWI. The system exhibits excess emission from mid-infrared (MIR) H-2 lines relative to dust, as identified in a previous Spitzer/IRS survey of local IR-luminous galaxies (LIRGs). It has been speculated that the bright H-2 emission could arise from widespread shocks associated with a powerful outflow driven by starburst and/or active galactic nucleus (AGN) activity. Methods. Using our multiwavelength datasets, we assessed and compared the resolved morphology and kinematics of multiphase gas tracers on subkiloparsec (subkpc) scales. We constructed emission line maps of several key tracers of the ionized, warm molecular, and cold molecular gas, such as [Ne II] 12.8 mu m, [O III]lambda 5007, H-2 0-0 S(3), and CO (J = 2-1), respectively. We performed a detailed decomposition of spectra extracted in resolved regions across the areas of emission, with a focus on the central similar to 3 kpc of the system covered by all our datasets. Results. We confirm the presence of a multiphase galactic biconical outflow along the minor axis of a highly inclined rotating disk, based on the multiphase gas morphology and prominent line broadening (FWHM > 500 km s(-1)) in the ionized gas tracers detected out to similar to 5 kpc from the nucleus. The molecular gas tracers are detected out to similar to 2 kpc, exhibiting a distinct X-shaped morphology and different velocity fields compared to the ionized gas, which we attribute to the higher concentration of molecular gas near the disk. We adopted a simple model to interpret the observed multiphase gas kinematics and infer an outflow velocity of similar to 500-600 km s(-1) similar to 350 km s(-1), and similar to 200-300 km s(-1), in the ionized, warm, and cold molecular phases, respectively. The corresponding mass outflow rates are similar to 0.3 - 2.3, similar to 31, and similar to 38 - 240 M-circle dot yr(-1). The cold molecular phase dominates both the total mass outflow rate and the associated kinetic energy (similar to 2 - 8 & times; 10(42) erg s(-1)). Via the JWST/MIRI-MRS detection of the [Ne V] 14.3 mu m line, we identified, for the first time, a dust-obscured AGN in IRAS F01364-1042. The low inferred AGN bolometric luminosity (1.2 - 1.8 & times; 10(43) erg s(-1)) suggests that the nuclear starburst alone, with a star formation rate of similar to 40 - 60 M-circle dot yr(-1), can account for the energy required to drive the outflow, although a more active AGN phase in the recent past might also have played a role. Conclusions. Our work showcases the need for multiwavelength observations in interpreting the gas dynamics in merger-driven dusty starbursts, as well as the capability of JWST/MIRI-MRS in uncovering obscured low-luminosity AGNs that could prove common in these systems.