
Тезисы конференции ФизикА.СПб 2017
The z abs = 2.504 Lyman Limit system (LLS) towards the quasar Q1009+2956 is one of the first absoption systems where the deuterium abundance (D/H ratio) has been measured. Since the last measurement by Burles and Tytler (1998) the quasar has been observed plenty of times with the Keck telescope increasing the signal-to-noise ratio by a factor of a few.