Multi-wavelength probes of distant lensed galaxies

TL;DR

This paper reviews recent multi-wavelength observations of distant lensed galaxies, highlighting discoveries enabled by gravitational lensing and discussing the challenges in accurately estimating galaxy properties due to differential magnification.

Contribution

It provides a comprehensive overview of multi-wavelength studies of lensed galaxies, emphasizing new techniques and the impact of gravitational lensing on observations.

Findings

Submm surveys efficiently select strong gravitational lenses.

Blind mm-wave redshifts are feasible with gravitational magnification.

Emission line diagnostics are less affected by differential magnification.

Abstract

I summarise recent results on multi-wavelength properties of distant lensed galaxies, with a particular focus on Herschel. Submm surveys have already resulted in a breakthrough discovery of an extremely efficient selection technique for strong gravitational lenses. Benefitting from the gravitational magnification boost, blind mm-wave redshifts have been demonstrated on IRAM, SMA and GBT, and follow-up emission line detections have been made of water, [OIII], [CII] and other species, revealing the PDR/XDR/CRDR conditions. I also discuss HST imaging of submm lenses, lensed galaxy reconstruction, the prospects for ALMA and e-Merlin and the effects of differential magnification. Many emission line diagnostics are relatively unaffected by differential magnification, but SED-based estimates of bolometric fractions in lensed infrared galaxies are so unreliable as to be useless, unless a lens mass model is available to correct for differential amplification.