| Description |
On the extragalactic side, one of the most remarkable results coming
out of Herschel is the discovery of extremely bright (>100 mJy in the
SPIRE bands) gravitationally lensed galaxies. The great sensitivity
and mapping speed of SPIRE have enabled us to find these rare
extraordinary objects. What is truly exciting about these bright
lensed galaxies is that they enable a variety of detailed
multi-wavelength follow-up observations, shedding new light on the
physical properties of these high-redshift sources. In this regard,
our OT1 program, SPIRE Snapshot Survey of Massive Galaxy Clusters
turned out to be a great success. After imaging virgul50 galaxies out of
279 in the program, we have already found two spectacularly bright
lensed galaxies, one of which is at a redshift of 4.69. This type of
cluster-lensed sources are not only bright but also spatially
stretched over a large scale, so ALMA (or NOEMA in the north) is
likely to be able to study them at the level of individual GMCs. Such
studies will open up a new frontier in the study of high-redshift
galaxies.
Here, we propose to extend this highly efficient and effective survey
of gravitationally lensed galaxies to another 353 clusters carefully
chosen from the SPT and CODEX cluster samples. These samples contain
newly discovered high-redshift (z>0.3) massive (>3-4e14 Msun)
clusters, which can be used as powerful gravitational lenses to
magnify sources at high redshift. With the OT1 and OT2 surveys
together, we expect to find virgul20 highly magnified SPIRE sources with
exceptional brightnesses (assuming a discovery rate of virgul1/30). Such a
unique sample of extraordinary objects will enable a variety of
follow-up sciences, and will therefore remain as a great legacy of the
Herschel mission for years to come. |
