Multiresolution HEALPix Maps for Multiwavelength and Multimessenger Astronomy

Abstract

HEALPix—the Hierarchical Equal Area isoLatitude Pixelization—has become a standard in high-energy and gravitational wave astronomy. Originally developed to improve the efficiency of all-sky Fourier analyses, it is now also utilized to share sky localization information. When used for this purpose the need for a homogeneous all-sky grid represents a limitation that hinders a broader community adoption. This work presents mhealpy, a Python library able to create, handle and analyze multiresolution maps, a solution to this problem. It supports efficient pixel querying, arithmetic operations between maps, adaptive mesh refinement, plotting, and serialization into FITS—Flexible Image Transport System—files. This HEALPix extension makes it suitable to represent highly resolved region, resulting in a convenient common format to share spatial information for joint multiwavelength and multimessenger analyses.