Yup, that is ash. Those rings look great to me! Little earlywood and a lot of latewood, which indicates high specific gravity (SG). This is a good thing with ring porous woods such as ash; the higher the SG, the better! Ash can be really variable in SG, with some pieces exceptionally good and others dramatically low. If this bow turns out good, you might want to harvest more ash from that specific patch of trees...
