Imaging the z=0.9 Absorbing Cloud toward 1830-211

Abstract

We present spectroscopic imaging observations of the molecular and HI 21cm absorbing cloud at z = 0.885 toward the `Einstein ring' radio source PKS 1830-211. We derive a cloud size between 10 h^{-1} pc and 600 h^{-1} pc, and M(H_2) > 2.6x10^{4} h^{-2} Msolar. The temperature of the ambient radiation field is 4.5+/-0.9 K, consistent with the microwave background temperature at z = 0.885. The velocity difference for absorption on opposite sides of the ring is -146 km s^{-1}, which is consistent with the galaxian rotation velocity derived from gravitational lens models.

for `Probing the Intergalactic Medium with QSO Absorption Lines,' ed. P. Petitjean (IAP: Paris)