Re: NOTE -- wrong magnitudes on individual images

From: Vitaliy Fadeyev (VAFadeyev@lbl.gov)
Date: Mon Apr 05 2004 - 11:20:44 PDT

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    No there were not a whole lot of those, just a couple of cases
    with 1 CR and 3 clean images with small signals. Then the sum was
    brighter. I chalked them up to the CR neighbouring pixels summing up
    with the fluctuations. Usually a look at the flux significance was
    good enough.

    vitaliy

    "Rachel G." wrote:

    > In cases where there are two CRs, and no host, one
    > couldn't be confident it was a real event anyway. In cases
    > where there were 3 good, consistent, and clean regions, but
    > CRs in the 4th image, CRs should have been efficiently
    > flagged prior to the sum.
    >
    > The point is that if there were a lot of cases with 3
    > consistent images going into the sum, but a summed magnitude
    > which was much *brighter* than those 3 individual images,
    > then one should get concerned and say something.
    >
    > On Mon, 5 Apr 2004, Vitaliy Fadeyev wrote:
    >
    > >
    > >
    > > Sorry for confusion. I meant only cases where there is 1 or more CR clearly
    > > present in individual images.
    > >
    > > vitaliy
    > >
    > >
    > > "Robert A. Knop Jr." wrote:
    > >
    > > > On Mon, Apr 05, 2004 at 10:02:48AM -0700, Vitaliy Fadeyev wrote:
    > > > >
    > > > >
    > > > > That's not so great. The individual magnitudes may have entered in
    > > > > my decision-making in some cases. Granted those cases were doubtful
    > > > > to start with.
    > > >
    > > > In any event, you should not have thrown out a candidate because all the
    > > > individual magnitudes were consistent with each other and different from
    > > > the subtraction magnitude. If you saw a case where that happens, and
    > > > the individual magnitudes were *dimmer*, it indicates that something is
    > > > wrong, not that it's a bad candidate. (That's how Rachel and I found
    > > > the bug in the first place.)
    > > >
    > > > The only thing about those magnitudes that should affect whether or not
    > > > a candidate is a good one is if the individual images are *consistent*
    > > > with each other. Which this bug does not affect, anyway.
    > > >
    > > > -Rob
    > > >
    > > > --
    > > > --Prof. Robert Knop
    > > > Department of Physics & Astronomy, Vanderbilt University
    > > > robert.a.knop@vanderbilt.edu
    > >

    --
    -------------------------------------------------
     Vitaliy Fadeyev
     SCP group at LBNL
     phone:  510-486-4169
     web:    http://www-physics.lbl.gov/~fadeyev/
    -------------------------------------------------
    


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