Re: mags

From: Rachel G. (gibbo@panisse.lbl.gov)
Date: Mon Mar 01 2004 - 14:27:14 PST

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    Ariel,

            Using Rob's templates :

    Type Ia at -7 (rest) has :

             F850LP F775W
    z z'_AB z'_vega i'_AB i'_vega
    ---- ----- ------- ----- -------
    1.50 25.2 24.6 26.0 25.6
    1.20 24.5 23.9 25.0 24.6
    0.85 23.8 23.2 24.0 23.6

            Limiting magnitudes for the search images should be
    approximately as follows :

                         F850LP F775W
                     z'_AB z'_vega i'_AB i'_vega
                     ----- ------- ----- -------
     3 sigma limit : 26.7 26.1 26.8 26.4
    10 sigma limit : 25.3 24.7 25.4 25.0

    N.b.,

    assumed are average background conditions, and exposure
    times of 4x400s in z' and 1x400s in i'.

    also,
    z'_AB - z'_vega = 0.550
    i'_AB - i'_vega = 0.413

    On Wed, 25 Feb 2004, Ariel Goobar wrote:

    > Thanks. One quick thing though. I suppose that your
    > Vega -> AB conversions were just a quick approximation, right?
    > I do find somewhat different answers for the 2 filters.
    > Cheers,
    > Ariel
    >
    >
    > On Wed, 25 Feb 2004, Rachel G. wrote:
    >
    > >
    > > Hi Ariel,
    > >
    > > Yup, it's 775. I think what I've attached has *not*
    > > been normalized to one, so is the true throughput.
    > >
    > > This was the easy digging. The other numbers will
    > > come later today. Rob and I are dug in over here getting
    > > the subtractions going.
    > >
    > > More soon!
    > >
    > > Rachel
    > >
    > > PS I've sent some information Vallery requested as well,
    > > please let him know, while things are pretty intense over
    > > here at Vandy this week, I'll find time here and there to
    > > answer questions. I'm hoping by end of next week Valelry
    > > and I will be able to independently put to rest questions
    > > regarding Riess' z=1.3 spectrum (well, at least it'll take
    > > me a week as I won't get back to it before I return to LBL).
    > >
    > > On Wed, 25 Feb 2004, Ariel Goobar wrote:
    > >
    > > > Hi Rachel,
    > > >
    > > > looking forward to your longer e-mail. In the mean time,
    > > > are you sure that it is the 775 filter we are using, i.e.
    > > > not the 814? If so, could you please send me the
    > > > response function. I have been unsuccesful in finding
    > > > this info in the HST pages. Probably just me looking
    > > > at the wrong place...
    > > >
    > > > Cheers,
    > > > Ariel

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