GALACTICNUCLEUS: A high-angular-resolution <i>JHK</i>_<i>s</i> imaging survey of the Galactic centre

The extreme extinction ($A_V\sim30$\,mag) and its variation on arc-second scales towards the Galactic centre hamper study of stars. Their analysis is restricted to near infrared (NIR) regime, where curve can be approximated by a broken power law. Therefore, correcting for fundamental analyse structure stellar population central regions our Galaxy. We aim to, (1) discuss different strategies de-redden photometry check usefulness extinction; (2) build maps NIR bands $JHK_s$ make them publicly available; (3) create de-reddened catalogue GALACTICNUCLEUS (GNS) survey, identifying foreground stars; (4) perform preliminary $K_s$ luminosity functions (KLFs). used from GNS survey whole catalogue. took red clump (RC) giant stars similar brightnesses as reference photometry. discussed limitations process analysed non-linear effects de-reddening. obtained high resolution ($\sim3''$) with low uncertainties ($\lesssim5$\,\%) computed average extinctions each covered GNS. checked that effectively correct differential reducing spread RC features factor $\sim2$. assessed validity law approach computing two equivalent $A_H$ using either $JH$ $HK_s$ same compatible within uncertainties. Finally, we KLFs lines sight found belonging NSD contain homogeneous significantly in innermost bulge regions.