# A near/mid infrared search for ultra-bright submillimetre galaxies: Searching for Cosmic Eyelash Analogues

## TL;DR

This study identifies potential ultra-bright high-redshift lensed submillimetre galaxy candidates by cross-matching near/mid-infrared data, revealing seven promising sources and their possible gravitational lensing environments.

## Contribution

The paper introduces a novel IR-based method to find bright, high-redshift, lensed submillimetre galaxy candidates over a large sky area.

## Key findings

- Seven candidate galaxies identified with IR colours similar to known high-redshift SMGs.
- Six of these candidates are near galaxy clusters/groups, suggesting potential lensing.
- Photometric redshifts of candidates range from 1.6 to 3.2.

## Abstract

We present results from a near/mid IR search for submillimetre galaxies over a region of 6230 sq deg. of the southern sky. We used a cross-correlation of the VISTA Hemispheric Survey (VHS) and the WISE database to identify bright galaxies (K_s <= 18.2) with near/mid IR colours similar to those of the high redshift lensed sub-mm galaxy SMM J2135-0102. We find 7 galaxies which fulfill all five adopted near/mid IR colour (NMIRQC) criteria and resemble the SED of the reference galaxy at these wavelengths. For these galaxies, which are broadly distributed in the sky, we determined photometric redshifts in the range z=1.6-3.2. We searched the VHS for clusters of galaxies, which may be acting as gravitational lenses, and found that 6 out of the 7 galaxies are located within 3.5 arcmin of a cluster/group of galaxies. Using the J-K_s vs J sequences we determine photometric redshifts for these clusters/groups in the range z=0.2-0.9. We propose the newly identified sources are ultra-bright high redshift lensed SMG candidates. Follow-up observations in the sub-mm and mm are key to determine the ultimate nature of these objects.