2026A&A...707A..20L

Aims. We investigated the interplay between dense molecular gas, star formation, and active galactic nucleus (AGN) feedback in the luminous IR galaxy NGC 1068 at sub-kiloparsec scales.
Methods. We present the HCN (4-3) and HCO⁺ (4-3) maps of NGC 1068 obtained with JCMT as part of the Mapping the dense molecular gas in the strongest star-forming galaxies (MALATANG) project, and perform spatially resolved analyses of their correlations with IR luminosity and soft X-ray emission.
Results. The spatially resolved relations between the luminosities of IR dust emission and dense molecular gas tracers (L_IR - L'_dense) are found to be nearly linear, without clear evidence of excess contributions from AGN activity. The spatially resolved X-ray emission ($ L^{\mathrm{gas}}_{0.5{-}2\,\mathrm{keV}} $) displays a radially dependent twofold correlation with the star formation rate (SFR), suggesting distinct gas-heating mechanisms are at play in areas between the galaxy center and the outer regions. A super-linear scaling is obtained in galactic center regions with SFR surface densities (Σ_SFR) > 8.2 × 10^–6M_⊙ yr^–1 kpc^–2: log($ L^{\mathrm{gas}}_{0.5{-}2\,\mathrm{keV}} $/erg s^–1) = 2.2 log(SFR/M_⊙ yr^–1) + 39.1. We further find a statistically significant super-linear correlation (β = 1.34 ± 0.86) between $ L^{\mathrm{gas}}_{0.5{-}2\,\mathrm{keV}} $/SFR and the HCN(4-3)/CO(1-0) intensity ratio, whereas no such trend is seen for HCO⁺(4-3)/CO(1-0) or CO(3-2)/CO(1-0). These findings indicate that AGN feedback does not dominate star formation regulation on sub-kiloparsec scales, and that the excitation of dense gas traced by HCN (4-3) may be more directly influenced by high-energy feedback processes compared to HCO⁺ (4-3) and CO (3-2).