# Searching For the 380 GHz H2O emission from the High-z lensed QSO MG J0414+0534

## TL;DR

This study reports a tentative detection of 380 GHz water emission from a high-redshift lensed quasar using ALMA, revealing potential spatial displacement of emission regions and flux ratio anomalies.

## Contribution

First detection attempt of 380 GHz H2O line in a high-z lensed QSO, suggesting complex spatial emission structure and flux ratio anomalies.

## Key findings

- Tentative detection of 380 GHz H2O line emission.
- Line emission shows broad velocity width (~290 km/s).
- Flux ratio anomalies imply multiple emission regions.

## Abstract

We report the result of our search for the 380 GHz H2O line emissions from the quadruply lensed QSO MG J0104+0534 at z = 2.639 with the Atacama Large Millimeter/submillimeter Array (ALMA). Our observation shows a tentative detection of the 380 GHz line from the lensed QSO, and line spectrum shows a broad spectral distribution that has a velocity width of ~290 km/s and a peak flux of ~0.8 mJy. The integrated-intensity map of the H2O line show lensed emissions at the A1 and A2 component of the QSO, with the A2 component slightly resolved. The integrated line flux ratio between the A1 and A2 component shows unexpected difference with the continuum flux ratio. Based on our gravitational lens modeling assuming our tentative detection is real, this flux ratio anomaly would suggest that the 380 GHz line emissions come from two or three spatially displaced locations in the QSO, with the dominant one located at the position of the continuum emission from the QSO and the other one(s) displaced from the continuum by ~1.5 kpc on the source plane.