Linking the small scale relativistic winds and the large scale molecular outflows in the z = 1.51 lensed quasar HS 0810+2554

TL;DR

This study uses ALMA observations of a gravitationally lensed quasar at z=1.51 to analyze the kinematics and morphology of molecular gas, revealing rotating gas structures and high-velocity outflows, linking small-scale winds to large-scale molecular outflows.

Contribution

First detailed ALMA analysis linking small-scale relativistic winds with large-scale molecular outflows in a high-redshift lensed quasar.

Findings

Detection of rotating molecular gas with triple-peak CO line structure.

Possible high-velocity CO emission clumps up to 1702 km/s.

Large-scale molecular wind momentum below energy-conserving outflow predictions.

Abstract

We present Atacama Large Millimeter/submillimeter Array (ALMA) observations of the quadruply lensed z=1.51 quasar HS 0810+2554 which provide useful insight on the kinematics and morphology of the CO molecular gas and the ~2 mm continuum emission in the quasar host galaxy. Lens modeling of the mm-continuum and the spectrally integrated CO(3-2) images indicates that the source of the mm-continuum has an eccentricity of e~0.9 with a size of ~1.6 kpc and the source of line emission has an eccentricity of e~0.7 with a size of ~1 kpc. The spatially integrated emission of the CO(2-1) and CO(3-2) lines shows a triple peak structure with the outer peaks separated by Dv_21 = 220 +\- 19 km s^-1 and Dv_32 = 245 +/- 28 km s^-1, respectively, suggesting the presence of rotating molecular CO line emitting gas. Lensing inversion of the high spatial resolution images confirms the presence of rotation of the line emitting gas. Assuming a conversion factor of alpha_CO = 0.8 M_solar (K km s^-1 pc^2)^-1 we find the molecular gas mass of HS 0810+2554 to be M _ Mol = [(5.2 +/- 1.5)/mu_32] x10^10 M_solar, where mu_32 is the magnification of the CO(3-2) emission. We report the possible detection, at the 3.0 - 4.7 sigma confidence level, of shifted CO(3-2) emission lines of high-velocity clumps of CO emission with velocities up to 1702 km s^-1. We find that the momentum boost of the large scale molecular wind is below the value predicted for an energy-conserving outflow given the momentum flux observed in the small scale ultrafast outflow.