Dating individual quasars with the He II proximity effect
Evidence for short ~ 1 Myr lifetimes from the He II proximity zones of z ~ 4 quasars
The Evolution of the He II-ionizing Background at Redshifts 2.3 < z < 3.8 Inferred from a Statistical Sample of 24 HST/COS He II Lya Absorption Spectra
The first measurement of the quasar lifetime distribution
Instrument
COS, COS/FUV, COS/NUV
Temporal Coverage
2015-08-28T02:05:40Z/2015-11-11T01:32:23Z
Version
1.0
Mission Description
Launched in 1990, the NASA/ESA Hubble Space Telescope remains the premier UV and visible light telescope in orbit. With well over 1.6 million observations from 10 different scientific instruments, the ESA Hubble Science Archive is a treasure trove of astronomical data to be exploited.
European Space Agency, Worseck et al., 2016, 'A Potential Paradigm Shift in our Understanding of Helium Reionization', 1.0, European Space Agency, https://doi.org/10.5270/esa-wf4h9z3