NOAO < 2020DECADAL < Topics

The future of the Blanco + DECam post-DES

The DES survey is due to end next year (assuming there is an extension), nevertheless DECam will remain available on the Blanco for community use, and demand is always high. To quote Lori Allen’s proposed topic for Mayall+DESI in the same, but later, circumstances: "One can envision a future that makes use of this powerful capability for a small number of coordinated surveys, for instance."

Proposed by Tim Abbott (CTIO/NOAO)

Comments (1):

Blanco + DECam is the only prime-focus + large-FOV telescope in the southern hemisphere before LSST's operation. To enlarge the science output of DES and future LSST, I'd suggest DECam to start multi-narrowband imaging in the post-DES era. The multi narrowband imaging with specially selected multi narrowband filters would help to increase the accuracy of photo-z, to effectively select thousands to millions of emission line galaxies such as Ha, [OIII], [OII], Lya emitters, and to hunt the diffuse nebular emissions of distant objects, e.g., Lya nebulae, Ha nebulae, [OIII] nebulae, etc. All these are hard to be selected with broadband imaging such as DES and LSST. Currently, we have successfully taken the first DECam narrowband survey to probe the Cosmic Reionization. The first results are quite successful and listed as the 2017 NOAO science highlights. Soon, there will be a second narrowband filter, a Ha filter, for DECam. The Ultra-Deep Ha imaging with DECam will help us to measure the HI gas of our Galaxy, and select distant emission line galaxies such as Lya at z~4.5 and [OIII] at z~0.3. In summary, Blanco + DECam is unique to take multi narrowband imaging for the southern sky, which can effectively boost the science output of DES and LSST.

Comment by Zhenya Zheng (Shanghai Astronomical Observatory)