On the Steel Breeze (Poseidon's Children #2) by Alastair Reynolds

The award-winning author of the Revelation Space series continues his Poseidon's Children saga as the next generation of the Akinya family crosses interstellar space seeking humanity’s future...

Chiku Akinya, great granddaughter of the legendary space explorer Eunice Akinyaand heir to the family empire, is just one among millions on a long one way journey towards a planet they hope to call their new home. For Chiku, the journey is a personal one, undertaken to ensure that the Akinya family achieves its destiny among the stars.

The passengers travel in huge self-contained artificial worlds—holoships—putting their faith in a physics they barely understand. Chiku’s ship is called Zanzibar—and over time, she will discover it contains an awesome secret—one which will lead her to question almost every certainty about her voyage, and its ultimate destiny...