Compact dust emission in a gravitationally lensed massive quiescent galaxy at z = 2.15 revealed in ~130 pc-resolution observations by ALMA

Understand

We present new observations of MRG-M2129, a quiescent galaxy at z = 2.15 with the Atacama Large Millimeter/submillimeter Array (ALMA).

• With the combination of the gravitational lensing effect by the foreground cluster and the angular resolution provided by ALMA, our data reveal 1.2 mm continuum emission at $\sim130$ pc angular resolution.
• Compact dust continuum is detected at 7.9 $\sigma$ in the target but displaced from its stellar peak position by $62 \pm 38$ mas, or $\sim169 \pm 105$ pc in the source plane.
• We find considerably high dust-to-stellar mass ratio, $4 \times 10^{-4}$.