First detection of HCO⁺ absorption in the magellanic system

We present the first detection of HCO⁺ absorption in the Magellanic System. Using the ATCA, we observed nine extragalactic radio continuum sources behind the Magellanic System and detected HCO⁺ absorption toward one source located behind the leading edge of the Magellanic Bridge. The detection is located at an LSR velocity of , with an FWHM of , and an optical depth of . Although there is abundant neutral hydrogen (H i) surrounding the sight line in position-velocity space, at the exact location of the absorber the H i column density is low, , and there is little evidence for dust or CO emission from Planck observations. While the origin and survival of molecules in such a diffuse environment remain unclear, dynamical events such as H i flows and cloud collisions in this interacting system likely play an important role.