Re: cluster obs requirements

From: marek kowalski (mpkowalski@lbl.gov)
Date: Fri Jan 27 2006 - 11:54:31 PST

  • Next message: Marc Postman: "Re: cluster obs requirements"

    Hello Marc,

    I just want to make sure we phrase it consistently. In the SNe
    observing requirement section we say 515 seconds exposure in I and 340
    seconds in the four z-band exposures. That makes a ratio of 1:2.64.
    The waek lensing section says 25% to 75% which is close enough to this
    ratio but different from 4:1.

    Cheers,

    Marek
    On Jan 27, 2006, at 11:43 AM, Marc Postman wrote:

    > Here are our expected photometric errors in i775 and z850 - as Henk
    > knew, the 4:1 exposure ratio for z850:i775 yields comparable errors at
    > each AB mag interval. these are based on scaling our Lynx (z=1.27)
    > mosaic exposures to the exptimes we will have in our co-added data. I
    > am modifying the cluster obs reqs section accordingly and making the
    > CMR slope/scatter measurements the main drivers.
    >
    > <SNeHST_photerr_vs_mag.eps>
    > On Jan 27, 2006, at 2:07 PM, Saul Perlmutter wrote:
    >
    >> ...and of course, show that our new F775 exposures (515 sec times ~7
    >> or 8 orbits co-added) is exactly what we need!
    >>
    > -----------------------------------------------------------------
    > Marc Postman Email: postman@stsci.edu
    > STScI - CMO Phone: +1-410-338-4340
    > 3700 San Martin Drive Fax: +1-410-338-4424
    > Baltimore, MD 21218 U.S.A. http://www.stsci.edu/~postman
    >
    >

    --------------------------------------------------------------
    Marek Kowalski Lawrence Berkeley National Laboratory
    mpkowalski@lbl.gov 1 Cyclotron Road, MS 50R5008
    (510) 486 4652 Berkeley, CA 94720-8160
    --------------------------------------------------------------

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