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We present the first flexion-focused gravitational lensing analysis of thefirst of the strong-lensing "cosmic telescope" galaxy clusters, observed aspart of the Hubble Frontier Fields initiative. Using HST observations of Abell2744 (z = 0.308), we apply a modified Analytic Image Model (AIM) technique tomeasure source galaxy flexion and shear values at a final number density of 82arcmin$^{-2}$. By using flexion data alone we are able to identify the primarymass structure aligned along the heart of the cluster in addition to a majorsubstructure peak offset 1.43' from the cluster core. We generate two types ofnonparametric reconstructions: a flexion aperture mass map, which identifiesthe central potential and substructure peak with mass signal-to-noise of3.5$\sigma$ and 2.3$\sigma$ respectively; and a convergence map deriveddirectly from the smoothed flexion field. For the primary peak we find a massof $1.93\times10^{14}\,h^{-1}\,M_{\odot}$ within a 45" (145h$^{-1}$ kpc)aperture, and for the western substructure we find a mass of$7.12\times10^{13}\,h^{-1}\,M_{\odot}$ within a 25" (80h$^{-1}$ kpc) aperture.The associated peak velocity dispersions were determined to be $\sigma_v$ =1630 km/s and $\sigma_v$ = 766 km/s, respectively, by fitting nonsingularisothermal sphere profiles to the flexion data. Additionally, we usesimultaneous shear measurements to independently reconstruct the broadercluster mass structure, and find that it is unable to reproduce the small-scalestructure associated with the flexion reconstructions. Finally, we perform thesame analysis on the Abell 2744 parallel sky field, and find no strong phantomsignals in the noise reconstructions.

Flexion in Abell 2744