The First Detection of Neutral Hydrogen in Emission in a Strong Spiral Lens

TL;DR

This paper reports the first detection of neutral hydrogen emission in a strongly lensing spiral galaxy, providing insights into its mass and properties, and demonstrating the feasibility of such observations.

Contribution

It presents the first HI emission detection in a strong spiral lens galaxy, expanding methods for studying galaxy mass and structure through radio observations.

Findings

Detected HI in one spiral lens galaxy with a mass of ~1.77x10^9 solar masses.

Placed strong constraints on HI masses of non-detected sources.

Demonstrated challenges due to radio frequency interference in observations.

Abstract

We report HI observations of eight spiral galaxies that are strongly lensing background sources. Our targets were selected from the Sloan WFC (Wide Field Camera) Edge-on Late-type Lens Survey (SWELLS) using the Arecibo, Karl G. Jansky Very Large Array, and Green Bank telescopes. We securely detect J1703+2451 at z=0.063 with a signal-to-noise of 6.7 and W50=79+/-13 km/s, obtaining the first detection of HI emission in a strong spiral lens. We measure a mass of M(HI)= 1.77+/-0.06(+0.35/-0.75) x 10^9 M_(sol) for this source. We find that this lens is a normal spiral, with observable properties that are fairly typical of spiral galaxies. For three other sources we did not secure a detection; however, we are able to place strong constraints on the HI masses of those galaxies. The observations for four of our sources were rendered unusable due to strong radio frequency interference.