Key points are not available for this paper at this time.
We study the size and structure of globular clusters (GC) systems of 118 early-type galaxies from the NGVS, MATLAS, and ACSVCS surveys. Fitting S\'ersic profiles, we investigate the relationship between effective radii of GC systems (R₄, ₆₂) and galaxy properties. GC systems are 2--4 times more extended than host galaxies across the entire stellar mass range of our sample (10^8. 3 < M_* < 10^11. 6~M_). The relationship between R₄, ₆₂ and galaxy stellar mass exhibits a characteristic "knee" at a stellar mass of Mₚ 10^10. 8, similar to galaxy Rₑ--stellar mass relationship. We present a new characterization of the traditional blue and red GC color sub-populations, describing them with respect to host galaxy (g'-i') color (₆₈): GCs with similar colors to their hosts have a "red" ₆₈, and those significantly bluer GCs have a "blue" ₆₈. The GC populations with red ₆₈, even in dwarf galaxies, are twice as extended as the stars, suggesting that formation or survival mechanisms favor the outer regions. We find a tight correlation between R₄, ₆₂ and the total number of GCs, with intrinsic scatter 0. 1 dex spanning two and three orders of magnitude in size and number, respectively. This holds for both red and blue subpopulations, albeit with different slopes. Assuming that N₆₂, ₓ₎ₓ₀₋ correlates with M₂₀₀, we find that the red GC systems have effective radii of roughly 1-5\% R ₂₀₀, while the blue GC systems in massive galaxies can have sizes as large as 10\% R ₂₀₀. Environmental dependence on R₄, ₆₂ is also found, with lower density environments exhibiting more extended GC systems at fixed mass.
Lim et al. (Thu,) studied this question.