Friday, May 7, 2010

Hennawi Visit Do To List

Joe Hennawi came to visit today and thus we have a huge list of things to do now.

1. I've been setting the threshold incorrectly for testing the likelihoods. I need to do the following. This should actually speed things up a bunch because I'll need to calculate the likelihoods on a lot fewer objects.
-----a) Pick a set of targets (Threshold Set) in a known area from the test objects, say -1.25 < dec < 1.25 and 1 degree in ra spaced across the stripe (-20, -10, 0, 10, 20). The Threshold Set of targets occupies 5*2.5 = 12.5 deg2 of area.
-----b) Calculate the (new) likelihoods on the Threshold Set.
-----c) Determine a threshold (TH) of (X/deg2) by picking the objects with the top Y = X*12.5 likelihoods in the Threshold Set. The threshold will be the min(likelihood_ratio) of these Y objects.
-----d) Calculate the (new) likelihoods on all objects in the 3pc catalog that are on Stripe-82 (Truth Table Set).
-----e) We targeted at 80 targets/deg2 in this region, so we can get the effective area (A) of the Truth Table Set by dividing the # of objects (Z) / 80: A (deg2) of Truth Table Set = Z/(80 targets/deg2)
-----f) Determine the (new) targeted quasars (TQ) by saying that any quasar in the Truth Table Set with likelihood greater than TH.
-----g) The QSOs /deg2 = TQ / A.

2. Joe fixed his luminosity function code, so I can now run it to generate the Hopkins, Richards, Hernquist (2007) luminosity function.

3. Joe thinks we don't need to put a brightness cut on the quasar inputs. Gonna see if that changes things

4. David gave me SDSS DR7 Quasars to use as inputs into the Monte Carlo.

5. I should look at something in the target files called x2_star. This is the chi-squared distance of the objects from the stellar locus, and probably all likelihood targets have a x2_star which is big. We might be able to reduce the likelihood calculations by only calculating likelihoods on objects which pass a certain x2_star threshold.

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