From: Andy Howell (DAHowell@lbl.gov)
Date: Fri Mar 21 2003 - 14:50:21 PST
Colleagues,
Thank you to those that sent me comments on the previous draft. They
have been incorporated into this draft. First some comments of my own.
-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.
-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".
-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.
-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/fewpoints.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.
-Also in the final draft, we will not include redshifts for these SNe, or my
comments, obviously.
This is as much as I can contribute to the circular, so I am
turning over responsibility for further revisions to Mamoru.
-------------------------------------------------------------
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 XX supernovae found with Subaru
telescope +prime-focus 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).
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 XX SNe below.
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 XX
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.
SuF02-007 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
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.
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
We also report XX probable SNe. They are all either hostless
or offset from the host galaxy center, and have lightcurves
consistent with SNe, but have not spectral confirmation.
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.
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.
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.
SuF02-081 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.
SuF02-083 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.
SuF02-051 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?
-Andy
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