Formation of metal-free binaries: Impact of H$_{2}$ line cooling and CIE cooling

Understand

During primordial star formation, the main cooling channel is provided by H$_{2}$ and super-molecules, such as H$_{2}$ or H$_{2}$, at sufficiently high densities.

• When the latter form at $n_{\rm H}$ $\geq$ $10^{14}$~cm$^{-3}$, collision-induced emission (CIE) provides efficient gas cooling.
• We investigate how CIE cooling affects the formation of metal-free binaries comparing simulations with and without this process.
• Irrespective of the cooling mechanism, we find a typical protostellar mass range between 0.01 to 100 M$_{\odot}$.