NGC5253-DR2

The blue compact dwarf galaxy NGC 5253 hosts a very young central starburst. The center contains intense radio thermal emission from a massive ultracompact H II region (or supernebula) and two massive and very young super star clusters (SSCs), which are seen at optical and infrared wavelengths. The spatial correspondence between the radio and HST images over an area of < 0".5 is very uncertain because of the limitations of Guide Star Catalog II for HST absolute astrometry. Using the Gaia Data Release 2 catalog, we improve the absolute astrometry of the HST ultraviolet, optical and infrared images by a factor of ~10 and match them to the radio observations with an accuracy of 10-20 mas. We find that the radio and optical sources do not coincide and that there are three young SSCs at the center of NGC 5253.

This High Level Science Product contains the HST images for the center of NGC 5253 re-mapped on to the Gaia DR2 reference frame. Full details of the images are given in Table 2 of Smith et al. 2020. The ACS/WFC F814W image was first mapped to the DR2 astrometry using the DrizzlePac function 'tweakreg' to an accuracy of +/- 10 mas. The smaller field of view ACS/HRC/SBC and NICMOS/NIC2 images were then aligned to the transformed ACS/WFC F814W image to accuracies of +/- 12 mas and +/- 20 mas, respectively.