LaSilla/QUEST Survey Strategy

Details from Charlie Baltay and Peter Nugent (8/8/11) :

  • Annual search Period : main work on the supernova will be from Sept 1 through May 30. Survey also has access to 270 of photometric screening/follow-up on the Swope 1-m at Carnegie during this time. It is also, save for May, the best weather-wise though shortest months of the year. We will be finding them at other points in the year. The survey though won't stop.
  • Cadence : We are planning on a 2 or 3 day cadence with two 60 sec exposures each night to eliminate asteroids and other stuff. To start, we will be every 3-days. We might wish to shorten this to 2 days, but it is dependent on the number of chips we can finally use during the survey.
  • Depth : 20th in full moon, 21st in new moon.
  • Status and start date : We are shooting for regularly generating targets and running this September. Jan 1 is when we get access to the Swope. The detector and telescope have now been running producing science quality data since Sept 2009. We have been mostly searching for RRLyrae stars and Trans Neptunian Objects until now and generating reference scans for the supernova search in the region of declinations between +25 and -25 degrees, skipping the galaxy.
  • Length of survey and long term status: We have a signed MOU with ESO to have full time of the telescope (i.e 90% with 10% to Chileans) till Sept 2014, but this can be extended if there is a good reason.

Suggested SDSS DR7 footprint overlap

(added by Dave Young)

For transient searches contextual information about any object is key to understanding the nature of the source, especially just after discovery when we'll often only have one or two epochs of observations. At QUB we've developed a transient classifier that cross-matches the coordinates of newly discovered transients again historical catalogues - much like the OARICAL classifier currently being used by LSQ. At QUB we've found that the SDSS catalogues often provide the most valuable of all contextual data - it makes life a lot easier for us to tag a transient with an accurate initial classification if it's discovered in the SDSS footprint. To this end, it would be very useful if LSQ could prioritise targeting fields within the SDSS footprint. 

SDSS-DR7-Footprint.png--Here's the imaging footprint for SDSS DR7, which includes SDSS-I and SDSS-II (Legacy and SEGUE). There are two strips for each location since the CCDs have gaps between them, requiring a second offset strip for complete coverage. For more details see here:
LSQ survey coverage.png--And here's the imaging footprint for LSQ to date (lifted from Charlie's talk from the Feb 2012 meeting:
LSQ-SDSS-footprint-overlap.png--And finally here's a mashup of the two footprints. The shaded blue area is SDSS mapped to the LSQ footprint and the shaded red area is the currently proposed +25 and -25 degree LSQ supernova search area (from Sept-May).