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The Kilo Degree Survey (KiDS) is currently the only sky survey providing optical (ugri) plus near-infrared (NIR, ZYHJKS) seeing matched photometry over an area larger than 1000 deg2. This is obtained by incorporating the NIR data from the VISTA Kilo Degree Infrared Galaxy (VIKING) survey, covering the same KiDS footprint. As such, the KiDS multi-wavelength photometry represents a unique dataset to test the ability of stellar population models to return robust photometric stellar mass (M*) and star-formation rate (SFR) estimates. Here we use a spectroscopic sample of galaxies for which we possess ugriZY JHKs“gaussianized” magnitudes from KiDS data release 4. We fit the spectral energy distribution from the 9-band photometry using: (1) three different popular libraries of stellar population templates, (2) single burst, simple and delayed exponential star-formation history models, and (3) a wide range of priors on age and metallicity. As template fitting codes we use two popular softwares: LePhare and CIGALE. We investigate the variance of the stellar masses and the star-formation rates from the different combinations of templates, star formation recipes and codes to assess the stability of these estimates and define some “robust” median quantities to be included in the upcoming KiDS data releases. As a science validation test, we derive the mass function, the star formation rate function, and the SFR-M*relation for a low-redshift (z< 0.5) sample of galaxies, that result in excellent agreement with previous literature data. The final catalog, containing ∼ 290000 galaxies with redshift 0.01 < z< 0.9, is made publicly available.

When a supermassive black hole at the centre of a galaxy accretes matter, it gives rise to a highly energetic phenomenon: an active galactic nucleus. Numerous physical processes have been proposed to account for the funnelling of gas towards the galactic centre to feed the black hole. There are also several physical processes that can remove gas from a galaxy, one of which is ram-pressure stripping by the hot gas that fills the space between galaxies in galaxy clusters. Here we report that six out of a sample of seven ‘jellyfish’ galaxies—galaxies with long ‘tentacles’ of material that extend for dozens of kiloparsecs beyond the galactic disks—host an active nucleus, and two of them also have galactic-scale ionization cones. The high incidence of nuclear activity among heavily stripped jellyfish galaxies may be due to ram pressure causing gas to flow towards the centre and triggering the activity, or to an enhancement of the stripping caused by energy injection from the active nucleus, or both. Our analysis of the galactic position and velocity relative to the cluster strongly supports the first hypothesis, and puts forward ram pressure as another possible mechanism for feeding the central supermassive black hole with gas.