DES first-light countdown, 6 months to go

I have promised to provide updates on our progress towards the first light of the Dark Energy Survey’s, or DES. First light is the first official look at the sky after readying the camera and its detection software. If you recall, we were supposed to deliver the Dark Energy Camera, or DECam, imager this summer.

So, without further ado, I am pleased to announce: Here it is!

I have been collecting DES-related pictures and videos for a while and the picture to right by Fermilab photographer Reidar Hahn is by far my favorite shot of the imager (first published in Fermilab Today ). It shows the focal plane completely populated with 74 shiny, blue CCDs, ready to catch some extragalactic photons.

Shipment arrangements and installation schedule are being worked out as I write. Our team has already set foot in Chile to assemble at the Blanco Telescope the various parts that we tested on our Fermilab telescope simulator in February. Installation will start soon.

I am joining them in November in Chile and can hardly wait. But this is when my wave-like abilities, which I mentioned in a previous post, comes to play. My wave function is now quite stretched as I perform a variety of tasks these days. Read on and see it for yourself.

Galaxy clusters are my favorite thing in the universe, and in addition to my work on the DES cluster analysis group I am now building a new catalog based on the Sloan Digital Sky Survey, or SDSS, data. Our group at Fermilab is wrapping up all the parallel threads of work on that data set, and that means that I am doing a lot of writing these days, too. Papers are coming out soon and this is terrific news, which puts my mind at ease with respect to that nightmarish pressure for publications.

I’ve also been volunteered to help in the calibration group by writing a code, which was being referred to as “George” until we found a more appropriate name. But since people now ask me, “How is George doing?” all the time, I am afraid the name has stuck. Right now I am working in the first module, “George I”, to process a series of monochromatic calibration images and create a map of the system response curve at every point of the DECam focal plane. This new task is exciting because it connects the instrument I helped build with the science I want to do (good calibration is an essential requirement for cluster science) and it also gives me the opportunity to learn more about our data management system

The reason for my excitement about this is the fact that a reliable, fast and easy-to-use database is the key for success and productivity in our field. I use the SDSS SkyServer for all my SDSS analyses and it is just great to be able to upload a text file with sky coordinates and visualize, with a single click, all the objects you are interested in. Every time I submit a query to the SDSS database, using the CasJobs web interface or my own little scripts, I wonder what the DES equivalents for that will look like. It feels a little like waiting for the next release of your favorite gadget. And as a heavy user and big fan, I, of course, have my own wish list of improvements.

My number one wish? Support to upload my own little codes, in addition to data tables, and run them directly on the query outputs. This way I could save only the processed tables, use them later in combination with other data, make all my plots and download only the final results. That would make my work so much easier!

Well, but I’d better stop here and go back to work. George is doing well today, but there is still a long way to go. I will be back with more updates soon. Stay tuned.

–Marcelle Soares-Santos

Tags: Cosmic Frontier, Dark Energy Camera, Dark Energy Survey, DECam, DES