From: clidman (clidman@eso.org)
Date: Thu Mar 20 2003 - 11:04:39 PST
Dear All,
Here are some additional comments on some of the candidates.
>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.
I think the "SN" classification is correct. The chisq per DOF is large
(2.5) for a type Ia, but is it large enough to reject a type Ia in
favour of a type II?
In regards to the VLT spectrum of this target, the position angle of the slit was set to 50.69 degrees
and passed through offset star A and the candidate. The bright galaxy, which may or may not be the host is
perpendicular to this line. So, the fact that the OII line lies right on top of the SN spectrum is
perhaps not significant. There maybe; however, very faint OII emission 1.5" and 5" NE of the
host. I've left a copy of the 2d spectrum on http://www.sc.eso.org/~clidman/
> 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
> SuF02-012 02:18:51.59 -04:47:24.8 25.1 1.3: SN 0.2" N Many minima in z space. Grism spectra exist. LC poor, but declining @ z=1.3
I don't think we can report a redshift for either of these candidates
in the IAU Circular.
> 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.
I agree with Andy, I think this should go from the circular. The same goes
for 028, 59, 083
Cheers, Chris.
Andy Howell wrote:
> Colleagues,
> (It is easiest to read this mail in a fixed width font in a big window.)
> Here is my proposed revision of the circular for the Fall 2002
> Subaru run in the format we discussed at the teleconference.
> We need to settle some outstanding issues that I have
> highlighted below. Once I hear back from the appropriate
> people I will make the next draft and send it to Mamoru to make the
> final version.
>
> If you want to refer to the data that I was looking at to generate
> the comments I made for each SN, SNMinuit fits are here:
> http://panisse.lbl.gov/collab/observing/schedule2002/2002B/lightcurves/
> The spectra pages are here: http://panisse.lbl.gov/collab/data/spec/
>
> ------------------
> M. Doi, Univ. of Tokyo, on behalf of the Supernova Cosmology
> Project (cf. IAUC 7763 and 7764, plus V. Prasad, G. Sainton, E.
> Smith, and A. Spadafora) 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).
> We took search images on Nov. 3.
>
> Follow-up photometry was carried out with Suprime-Cam, and we
> confirmed SN signals at least 3 epochs among 7
> (Nov.3,6,10,28,30,Dec.7,8) for 30 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.
>
> 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 1.3: SN 0.2" N Many
> minima in z space. Grism spectra exist. LC poor, but declining @ z=1.3
> 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
> SuF02-061 02:17:22.73 -05:16:56.1 24.7 1.08: ? 0.0" I
> don't have the spectrum. No LC.
> 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.
> SuF02-021 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.
> SuF02-028 02:16:56.37 -05:00:57.4 24.9 0.347:* ? 1.5" SE No
> LC. Chris: No evidence for a SN. Another weird one. The spectrum falls
> off after H-alpha.
> 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?
> SuF02-083 02:18:06.22 -05:00:38.1 26.0 1.272* ? 0.4" S Flat
> spectrum.
>
> SCPname R.A. (J2000) Decl. i' host info.
> SuF02-034 02:18:31.21 -05:01:24.4 25.6 0.2" N
> SuF02-004 02:18:09.01 -04:54:17.9 25.1 0.6" SE
> SuF02-086 02:17:16.18 -05:06:02.7 26.2 no host
> SuF02-076 02:16:26.37 -05:04:32.5 26.1 no host
> SuF02-J01 02:17:45.97 -04:36:46.2 25.2 0.2" W
> SuF02-051 02:17:27.48 -04:40:45.2 25.4 no host
> SuF02-057 02:20:13.92 -05:07:36.0 25.6 no host
> SuF02-056 02:20:00.03 -04:44:20.2 24.3 0.5" SE
>
> Outstanding questions:
> - If SuF-065 drops like a Type II according to Peter, why does it look
> reasonable as a SNMinuit fit?
> I he is right about that, then does that not call into question all
> SNMinuit fits?
>
> - SuF02-061, 21 are now "?", but could be resurrected as SN depending on
> the spectra,
> which I don't have because they are from the last night of Keck. I also
> don't have SuF02-077.
> I don't know their reduction status. Lifan, can you get the data from
> Greg and look at it?
>
> - Peter says SuF-060 is in E galaxy, thus the classification as Ia. I
> didn't note where that came from.
> Are you confident of that, and do we want to classify something as a Ia
> at z=1 based on this?
> Maybe we should note the reason for the classification.
>
> - SuF02-081 I have listed as '?' now, because I'm not sure if we can
> rule out some kind of AGN.
> It has 0 offset from core. I am open to suggestions. Greg, you
> mentioned the possibility of
> a BLLac. You know more about that than me. Is this possible?
>
> - We may have to lose 005, 028, 059, 083, and possibly (61 and 21
> pending looks at the Keck spectra)
> unless someone finds evidence that they are SNe. I propose dropping
> them, and I will do that
> in the next draft unless someone has a reason to keep any of them.
>
> - Can someone give me LC points for the second set of SNe without
> spectra? What should we
> say about these?
>
> - I took off the date category, since they were all the same. If that
> information was correct,
> someone should add it to the text. I didn't really follow that part of
> the discussion today
> at the teleconference, so someone on the Subaru side will have to
> address this.
>
> - The original draft said: "The magnitude increase of the SNe compared
> with the images in the
> reference are given in the table below (photometric accuracy 0.1-0.2mag)."
> I don't think we need to say this explicitly because people will
> understand that we are
> reporting discovery magnitudes.
>
> -Andy
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