Extragalactic Strong Lensing : From Discovery to Exploitation
The Herschel Bright Sources catalogue: Finding lenses in a shallow and wide Herschel survey
Tom Bakx
S. Eales (Cardiff University)
Cardiff University
The H-ATLAS survey is one of the great legacies from the Herschel Space Observatory, detecting 300.000 galaxies over 590 sqr. deg. in five far-infrared wavebands. Our Herschel Bright Sources (HerBS) sample contains the 208 brightest, high-redshift (z_phot less than 2) sources from the H-ATLAS survey, consisting purely of unlensed HyLIRGs and lensed ULIRGs. The unlensed HyLIRGs are among the brightest sources in the universe; galaxies experiencing bursts of star-formation in different regions, simultaneously. The lensed sources allow for detailed and deep follow-up observations, and large unbiased samples of lenses can constrain cosmological models which can be constructed from the HerBS sample.

However, discerning between lensed and unlensed sources requires a more detailed understanding of the HerBS sample. 850µm observations of the HerBS sources with SCUBA-2 provide a new modified black-body template, from which we have calculated redshifts and luminosities with this template. We compared these to cosmological models, and find an overdensity of lensed sources in the equatorial fields. Preliminary analysis of VIKING NIR observations of our sample show that between 70 and 90% of our HerBS sources have probable lensing galaxies. In our talk, we will detail how the HerBS sample will help towards constructing large samples of lenses, interesting follow-up opportunities, and what the sample’s selection effects are.


09:00 - 10:30
EX - LT2 (200)