u − g color and age of our blue regions as a function of their distance from the center of the UDG. Black triangles represent the knots and filaments from Fumagalli et al. (2011). The black dotted and dashed lines indicate the age gradients we measured for a 9.4 kpc stream following Eq. (2) of Kenney et al. (2014), for two different ICM densities with ρ_ICM = 10⁻⁴ and 10⁻³ cm⁻³, respectively, as discussed in Sect. 4.2. The blue open circles and green open squares mark our u-band and UV-selected regions, respectively. The red crosses identify the Hα detected regions.