Re: our supernova, acs04-076

From: Lifan Wang (lifan@panisse.lbl.gov)
Date: Fri Apr 23 2004 - 12:49:10 PDT

  • Next message: Rachel A. Gibbons: "April IAUC as sent to Dan Green."

    Hi, Vallery,

            Can you make the raw stamp images together with the x,y offset
    applied for the drizzle available ?

            Cheers,

            Lifan

    On Thu, 22 Apr 2004, Vallery Stanishev wrote:

    > Hi,
    >
    > I started working on the grism data. On the bottom of the Twikki page
    > some figures can be seen. The SN is visible but the signal is very low
    > and in addition the spectrum is heavily contaminated by the close bright
    > galaxy. Have to find a way to get rid of it before any extraction of the
    > spectrum is attempted.
    >
    > Another problem is that the direct image is too shalow and the position
    > of the SN could not be accurately determined. This will affect the
    > accuracy of the wavelength solution. I put some rough wavelength marks
    > on one of the 2D images.
    >
    > On the third image (not directly visible from the page) are shown the
    > output of Multidrizzle and simpe shift & add. They seem to be almost
    > identical. The shifts for the "shift & add" image were determined from
    > the 0th orders of 4 bright compact sourses on CCD2. The images were
    > shifted by IRAF's IMSHIFT with frac. pixel shifts and interpolation type
    > 'drizzle[0.5]'. For the multidrizzle image shifts were not supplied and
    > the info comes from the headers (for the moment). PIXFRAC and SCALE 1
    > were used.
    >
    >
    > Vallery
    >
    >
    >
    > Rachel A. Gibbons wrote:
    > > Hi,
    > >
    > > Tony noticed that in my previous e-mail the days past discovery should
    > > read
    > >
    > > 1) 9 days (~3.5 rest frame days)
    > >
    > > 2) 13 days (~5 rest frame days).
    > >
    > > However, my conclusions are based on the correct scaling. Also, to be
    > > precise, the data are consistent with discovery at rest B max. Sorry for
    > > any confusion.
    > >
    > > Rachel
    > >
    > > On Mon, 19 Apr 2004, Rachel A. Gibbons wrote:
    > >
    > >
    > >>Hi everyone,
    > >>
    > >> It would appear our data are completely consistent with a supernova at
    > >>z=1.6 which was discovered at rest-frame optical maximum.
    > >>
    > >> Here's an update from the first round of follow-up ACS and NICMOS
    > >>photometry :
    > >>
    > >> 1) The discovery z' magnitude was z'=25.1 and 12 days later z'=25.5.
    > >>
    > >> 2) 16 days after discovery, the new J and H magnitudes are 24.37 and
    > >>24.03.
    > >>
    > >> All mags quoted here are Vega.
    > >>
    > >> The remainder of the follow-up observations for this candidate will be
    > >>in J & H and will extend through 23 May (yes, that's during the next
    > >>search run).
    > >>
    > >> It's unfortunate we're following it on the decline, but it's looking
    > >>good! Hooray!
    > >>
    > >>Rachel
    > >>
    > >>PS Sorry, no news yet to report on the grism data, except that we have it
    > >> and they pointed HST at the right part of the sky.
    > >>
    > >
    > >
    > >
    >
    >
    >

    -- 
    Lifan Wang           (510) 495 2733 (o)   (510) 704 0119 (h)
    


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