Measuring Feedback in Damped Lyα Systems
نویسندگان
چکیده
We measure feedback (heating rates) in damped Lyα systems (DLAs) from the cooling rate of the neutral gas. Since cooling occurs through [C II] 158 μm emission, we infer cooling from C II 1335.7 absorption lines detected with HIRES on the Keck I telescope. The inferred heating rates are 30 times lower than for the Galaxy ISM. At z ≈ 2.8 the implied star formation rate per unit area is logψ∗=−2.4±0.3 M⊙ y −1 kpc and the star formation rate per unit comoving volume logdρ∗/dt=−0.8±0.2M⊙ y −1 Mpc. This is the first measurement of star formation rates in objects that typify the protogalactic mass distribution.
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