NICER observation list: Target ID 359901

We propose here a joint study of the mm/X-ray variability of the brightest unobscured AGN in the southern sky, IC 4329A. We will use NICER and ALMA to monitor this source, observing it for 2 ks twice per day over ten consecutive days. The ALMA monitoring has already been approved (priority A). This would be the first time such monitoring is carried out with such a high resolution in the mm band (~20 pc), and the detection of correlated mm/X-ray variability would be crucial proof of the coronal origin of the nuclear radio emission in radio-quiet AGN. These observations would also be fundamental to understand the origin of the X-ray emission, proving, for the first time, that the X-ray corona is magnetically-heated.