GMRT detection of HI 21 cm - line absorption from the peculiar galaxy in Abell 2125
نویسنده
چکیده
Using the recently completed Giant Meterwave Radio Telescope, we have detected the HI 21 cm-line absorption from the peculiar galaxy C153 in the galaxy cluster Abell 2125. The HI absorption is at a redshift of 0.2533, with a peak optical depth of 0.36. The full width at half minimum of the absorption line is 100 km s. The estimated column density of atomic Hydrogen is 0.7×1022(Ts/100) cm . The HI absorption is redshifted by ∼ 400 km s compared to the [OIII] emission line from this system. We attribute this to an in-falling cold gas, or to an out-flowing ionised gas, or to a combination of both as a consequence of tidal interactions of C153 with either a cluster galaxy or the cluster potential.
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