The 19-year-old pianist and composer performed his most recent work all over Europe, Asia, and North America last year, winning prestigious awards in both London and Tokyo for his achievement at such a young age, and he hopes to continue composing now that he has returned to Chicago.
请教各位NN，这个正确句子中now that是什么成分？
（此非考点，但我看不懂）作者: 幻北 时间: 2017-1-31 19:17
now that做从属连词，是固定用法，表示“既然”