One H2 molecule per ten million H-atoms reveals sub-pc scale cold overdensities at z~4

P. Noterdaeme, S. Balashev, T. Berg +11

We present the detection and analysis of H2 absorption at z = 4.24 towards the bright quasar J0007-5705, observed with the Very Large Telescope as part of the ESPRESSO QUasar Absor…