HST/COS Observations of the Quasar Q0302-003: Probing the He II Reionization Epoch and QSO Proximity Effects

David Syphers, J. Michael Shull

Q0302-003 ($z=3.2860\pm 0.0005$) was the first quasar discovered that showed a He II Gunn-Peterson trough, a sign of incomplete helium reionization at $z>2.9$. We present its HS…