Spectral and angular differential imaging with SPHERE/IFS

Angular differential imaging (ADI) and spectral (SDI) are commonly used for direct detection characterisation of young, Jovian exoplanets in datasets obtained with the SPHERE/IFS instrument. We compare performance ADI, SDI, three combinations ADI SDI to find which technique achieves highest signal-to-noise ratio (S/N), we analyse their as functions integration time, field rotation, wavelength range. observations known exoplanets, namely Beta Pictoris b, 51 Eridani HR 8799 e, five techniques. split into subsets vary each parameter before data processed technique. The techniques applied using principal component analysis (PCA). tests show that a combination consistently better results than alone, simultaneously (combined imaging; CODI) achieved best results. time test shows targets separation larger 0.24 arcsec observed an more 10$^3$s were photon-noise limited. Field rotation strong correlation S/N rotations up 1 full width at half maximum (FWHM), after no significant increase is observed. Wavelength range variation general broader ranges, but clear seen. Spectral information essential boost compared regular ADI. Our suggest CODI should be preferred processing search new SPHERE/IFS. To optimise direct-imaging observations, exceed FWHM detect small separations.