Where are all the Baryons? Searching for the Missing Mass in OVI
Christopher Thom (U Chicago)
Observations of the CMB and high-z Deuterium yield a precise measurement of the baryon content of the universe. At z=3, the Lya forest can account for almost all the baryons, but at z=0 a large fraction is unaccounted for. Simulations suggest that up to 50% of the z=0 baryons lie in the Warm-Hot IGM (WHIM). One potential way to detect this mass is absorption lines of high-ionised OVI. I will present the result of a survey for OVI absorption in the HST/STIS archive. Among other results, we have found that a significant fraction of the OVI systems do not trace the WHIM, but are instead at cooler temperatures, and photoionised.
Contact: jrigby
Christopher Thom (U Chicago)
Observations of the CMB and high-z Deuterium yield a precise measurement of the baryon content of the universe. At z=3, the Lya forest can account for almost all the baryons, but at z=0 a large fraction is unaccounted for. Simulations suggest that up to 50% of the z=0 baryons lie in the Warm-Hot IGM (WHIM). One potential way to detect this mass is absorption lines of high-ionised OVI. I will present the result of a survey for OVI absorption in the HST/STIS archive. Among other results, we have found that a significant fraction of the OVI systems do not trace the WHIM, but are instead at cooler temperatures, and photoionised.
Contact: jrigby