Re: IAUC draft ver.6

From: Andy Howell (DAHowell@lbl.gov)
Date: Tue Mar 25 2003 - 14:49:48 PST

  • Next message: clidman: "Re: IAUC draft ver.6"

    Mamoru,
    That looks fine to me. The only think I would change is, "have not
    spectral confirmation"
    should be "do not have spectral confirmation."

    -Andy

    Mamoru Doi wrote:

    > Dear Andy and colleagues,
    >
    > Sorry for my slow response. I have been busy for a biannual
    > assembly of the astronomical society of Japan (Mar.23-26),
    > since I am in charge of the program.
    >
    > Let me write down responses to Andy's comments/questions first.
    >
    >> -SuF02-026 was not on the circular. Why is that? Spectra were
    >> indeterminate,
    >> but it has a light curve that looks like a SN. The LC says z=1.46 --
    >> where
    >> did that come from? I have not put it back on the list, but Mamoru may
    >> want to.
    >
    > I put this into not a possible AGN category.
    > We observed this object twice. There are two comments on this according to
    > my note.
    > The photometric redshift is estimated to be z=0.80.
    > 11/6 Keck weak SN signal
    > 11/9 VLT AGN? 1.46[OII]
    > Chris, do you think we should put this to a posible SNe?
    >
    >> -Update on SuF-065: Peter says Gerson's fit is only good because it can
    >> choose the date of max. His data has an additional constraining point.
    >> Plus he has ACS data. However, I believe there is something wrong
    >> with the
    >> photometry, because the spectrum looks like a Ia or Ib/c to both of us.
    >> II doesn't fit at any z. Chris says it is possible that the redshift is
    >
    > >from the big nearby galaxy. In the face of all of this uncertainty,
    >
    >> it remains a "SN".
    >
    > The last ACS photometry is crucial. Other results can be interpreted
    > as a Ia with large stretch factor.
    >
    >> -I still haven't heard back on the Keck spectra for 61, 21, 77, so I am
    >> going to pretend we don't have them and move forward.
    >
    > We won't include these unless we can get new information.
    >
    >> -The "light curves" of the candidates in the second category are not
    >> great.
    >> Since there could be host galaxy light, and I don't believe the limits,
    >> You can see them on a plot that Naoki gave me here:
    >> http://panisse.lbl.gov/collab/observing/schedule2002/2002B/lightcurves/fewpo
    >> ints.ps
    >> I have ordered these SNe in what I believe to be the rough order of
    >> believability that they are SNe (almost every one is a gray area). I left
    >> a break where I believe we should cut the list. This would mean
    >> throwing out:
    >> 61, 83, 21, 34, 81, 51, 05, 59
    >> I don't think we could defend these to Dan Green. I don't even know if
    >> we could defend some of the ones higher up on the list.
    >
    > O.K. These are the ones which don't have enough epochs for follow up
    > (< 4). If spectral information is poor, we should remove these 8.
    >
    > I attached the revised version, though this version still includes
    > comments in the table.
    >
    > Regards,
    >
    > -Mamoru
    >
    >
    > Ver.6
    > -------------------------------------------------------------
    >
    > M. Doi, Univ. of Tokyo, on behalf of the Supernova Cosmology
    > Project(cf. IAUC 7971, plus V. Fadeyev, B. Lee, V. Stanishev,
    > and R. Vogel) and the Subaru high-redshift supernova search
    > group (N. Yasuda, N. Kashikawa, K. Motohara, T. Morokuma,
    > K.Sekiguchi, G. Kosugi, H. Furusawa, Y. Komiyama, T. Takata,
    > M. Ouchi, Y. Ohyama, and Subaru Observatory SXDS Project members),
    > reports the discovery of 13 spectroscopically confirmed supernovae
    > and 9 probable supernovae found with Subaru telescope + Suprime-Cam
    > in SDSS i' band. Reference images were taken on Sep. 30 and Oct.1,
    > 2002. The limiting magnitude of reference images was about 26.6mag
    > (S/N=5 for 2arcsec aperture). All supernovae listed below were
    > discovered on search images from Nov. 3.3 (UT). The magnitudes
    > of the SNe after subtraction from reference images are given in
    > the table below (photometric accuracy 0.1-0.2mag).
    >
    > The supernova spectra were obtained with GMOS on Gemini-N on
    > Nov. 6, 8, and 9; with ESI on KeckII on Nov. 6, 7, 9,
    > and 10; with FORS2 on Yepun (VLT-UT4) on Nov. 7 - 11; and
    > with FOCAS on Subaru on Nov. 12. Redshifts were obtained for 13
    > SNe using either the host galaxy spectrum (denoted with *)
    > or with template spectrum fitting of a SN. SuF02-060 has
    > as spectrum consistent with a Type Ia SN, and it is in
    > an elliptical host galaxy.
    >
    > SCPname R.A. (J2000) Decl. i' z type offset Comments
    > SuF02-060 02:17:34.51 -04:53:46.6 24.5 1.063* Ia 0.0" LC ok. 7
    > points. s=0.80. Spectrum plausible, not convincing. Peter says E galaxy
    > -> Ia. Grism spectra exist.
    > SuF02-017 02:16:45.71 -05:09:51.2 25.0 1.03 Ia no host Feature
    > could be Si 4000 if smoothed, but maybe too broad. LC poor, but declining.
    > s=0.65.
    > SuF02-025 02:16:23.93 -04:49:29.4 24.5 0.606* Ia 0.2" W Si.
    > Confirmed Ia. Excellent LC. s=0.83, including rise.
    > SuF02-001 02:17:00.05 -04:58:19.6 23.4 0.57 Ia 0.5" W aka
    > SuF02-027. Certainly Ia. LC 7 points. Several sigma off, but
    > reasonable s=0.83
    > SuF02-065 02:17:34.53 -05:00:15.4 25.2 1.181* SN 1.3" SSE Peter
    > says LC is like Type II. SN minuit says Ia could fit s=1.07. Big errors,
    > residuals.
    > SuF02-071 02:17:08.63 -05:02:06.4 23.8 0.928* SN 1.4" E At that
    > redshift, Ia features do not seem to match. LC good fit, 7pts, falling,
    > s=0.86.
    > SuF02-037 02:17:43.30 -04:30:56.7 24.6 0.926* SN 0.4" E One bump
    > in the spectrum. Ok LC, rises, falls. 4 points, s=0.77
    > SuF02-000 02:17:42.54 -05:06:34.0 24.8 0.92* SN 0.5" NE Almost
    > all galaxy light in spectrum, but LC good -- rises, falls. s=0.73
    > SuF02-002 02:17:12.24 -04:55:08.7 24.4 0.823* SN 0.3" NW Chris
    > (prelim) says: Wiggles don't seem to match a Ia at this redshift. Now
    > says: Possible SN. Good LC fit, s=0.75
    > SuF02-055 02:18:53.20 -04:32:59.2 23.7 0.66: SN 0.6" N One bump
    > in the spectrum. Well fit LC, but only 4 points. s=1.08
    > SuF02-082 02:18:40.73 -05:03:44.3 25.3 0.623* SN 1.1" NNW
    > Essentially a featureless spectrum. LC not great, but rises, falls, 7
    > points, s=1.01 +/- 0.07
    > SuF02-077 02:18:35.15 -04:26:38.9 25.1 0.59: SN 0.6" NW I don't
    > have the spectrum. LC 4 points, rising, falling, s=0.73
    > SuF02-019 02:17:38.08 -05:08:46.8 24.5 0.505* SN 0.3" NW
    > Featureless, mainly galaxy light. LC poor, but declining.
    >
    > We also report 9 probable SNe. Follow-up photometry was
    > carried out with Suprime-Cam, and we confirmed SN signals
    > on at least 3 epochs among 7 (Nov.3,6,10,28,30,Dec.7,8)
    > for all objects below. They are all either hostless or
    > offset from the host galaxy center, and have light curves
    > consistent with SNe, but have not spectral confirmation.
    >
    > Chris: I don't think we can report a redshift for either of these
    > candidatesin the IAU Circular.
    > SuF02-012 02:18:51.59 -04:47:24.8 25.1 ? SN 0.2" N Many
    > minima in z space. Grism spectra exist. LC poor, but declining @ z=1.3
    > Lifan z=1.03
    > SuF02-007 02:18:52.36 -05:01:13.2 24.8 1.18: SN no host Chris
    > says z=1.54, but that would make it too bright. z uncertain -> type
    > uncertain. LC ok, s=0.99 @ z=1.18
    >
    >
    > SCPname R.A. (J2000) Decl. i' host info.
    > SuF02-028 02:16:56.37 -05:00:57.4 24.9 0.347:* SN 1.5" SE LC rises,
    > falls. Could be a SN. Chris: No evidence for a SN. Another weird one.
    > The spectrum falls off after H-alpha.
    > SuF02-004 02:18:09.01 -04:54:17.9 25.1 0.6" SE LC slow
    > decline, strange last point -- could be a SN.
    > SuF02-086 02:17:16.18 -05:06:02.7 26.2 no host LC 3
    > points + limits. Limits imply falling. Indeterminate. Could be a SN.
    > Lifan z=0.89??? any
    > SuF02-076 02:16:26.37 -05:04:32.5 26.1 no host LC 5
    > points, 3 clustered together, two lower. Probably declining.
    > SuF02-056 02:20:00.03 -04:44:20.2 24.3 0.5" SE LC 3
    > points, 1 limit. Falling.
    > SuF02-057 02:20:13.92 -05:07:36.0 25.6 no host LC Flat.
    > SuF02-J01 02:17:45.97 -04:36:46.2 25.2 0.2" W LC Flat.
    >
    > ----------------------------------------------------------------
    > We probably do not include the following 8.
    > ----------------------------------------------------------------
    > SuF02-061 02:17:22.73 -05:16:56.1 24.7 1.08: ? 0.0" I  don't
    > have the spectrum. 3 points on LC falling. Could be a SN. Could  be AGN
    > -- zero offset.
    > SuF02-083 02:18:06.22 -05:00:38.1 26.0 1.272* ? 0.4" S Flat
    > spectrum. LC not monotonic, 3 points. Limits imply falling.
    > SuF02-021 02:18:10.56 -04:40:20.6 24.6 0.69 ? 2.9" SSW Two LC
    > points. Drops like a rock. I don't have the spectrum, but Saul's notes
    > don't mention a match to a Ia.
    > SuF02-034 02:18:31.21 -05:01:24.4 25.6 0.2" N LC
    > strange. Very slow rise.
    > SuF02-081 02:20:07.55 -05:08:27.2 25.1 1.478* ? 0.0" Spectrum
    > misses big feature for Ia if z is correct. LC terrible at  z=1.48, 3
    > points. Could be AGN -- zero offset.
    > SuF02-051 02:17:27.48 -04:40:45.2 25.4 no host LC 3
    > points, 1 limit. Doesn't seem to fit a light curve.
    > SuF02-005 02:18:35.70 -04:31:11.0 24.6 0.863* ? 0.3" NE No LC.
    > No good SN fit. Chris: Weird. Very broad bump at 8500 Angstroms.
    > SuF02-059 02:20:28.06 -04:58:50.3 25.7 0.269* ? 0.2" E Spectrum
    > pretty flat. How can it be at I=25.7 and z=0.269? LC terrible, 3 points,
    > s=0.55, and huge errors. Is z wrong?
    >
    >
    >
    >
    > Mamoru Doi
    > Institute of Astronomy
    > School of Science
    > University of Tokyo
    > voice +81-422-34-5084
    > fax. +81-422-34-5041
    > doi@ioa.s.u-tokyo.ac.jp
    >
    >



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