Re: IAUC draft

From: Andy Howell (DAHowell@lbl.gov)
Date: Wed Mar 19 2003 - 15:32:54 PST

  • Next message: Robert A. Knop Jr.: "a note on differences vs. redshift"

    Mamoru Doi wrote:

    >Dear Chris,
    >
    >Thank you very much for your quick suggestions.
    >
    >
    >
    >>- VLT observations occurred on Nov. 7-11
    >>
    >>- If you wish to give more details, the VLT observations were done
    >>with FORS2 on Yepun (VLT-UT4)
    >>
    >>- The redshift of SuF02-065 is z=1.181 from the [OII] line.
    >>
    >>- The redshift of SuF02-017 from the VLT spectrum is probably z=1.03.
    >>Andy may want to confirm this.
    >>
    >>
    >I update the draft.
    >
    >
    >
    >>- There appears to be some strange characters associated with the listing
    >>for SuF02-005
    >>
    >>
    >I hope I fixed this correctly. The characters must be blank in Japanese
    >fonts, and it is hard for me to see those characters with my PC.
    >
    >Best regards,
    >
    >-Mamoru
    >
    >Ver.3
    >---------------------------------------------------------------------
    > 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 possible 29 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. 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).
    >
    >
    >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 19
    >SNe using either the host galaxy spectrum or with template spectrum
    >fitting of SN.
    >
    >
    >SCPname 2002 UT R.A. (J2000) Decl. i' z type host info.
    >SuF02-065 Nov. 3.3 02:17:34.53 -05:00:15.4 25.2 1.181 Ia 1.3" SSE
    >SuF02-060 Nov. 3.3 02:17:34.51 -04:53:46.6 24.5 1.063 Ia 0.0"
    >SuF02-007 Nov. 3.3 02:18:52.36 -05:01:13.2 24.8 1.18? Ia no host
    >SuF02-061 Nov. 3.3 02:17:22.73 -05:16:56.1 24.7 1.08? ? 0.0"
    >SuF02-017 Nov. 3.3 02:16:45.71 -05:09:51.2 25.0 1.03 Ia no host
    >SuF02-071 Nov. 3.3 02:17:08.63 -05:02:06.4 23.8 0.928 Ia 1.4" E
    >SuF02-037 Nov. 3.3 02:17:43.30 -04:30:56.7 24.6 0.926 Ia 0.4" E
    >SuF02-000 Nov. 3.3 02:17:42.54 -05:06:34.0 24.8 0.92 Ia? 0.5" NE
    >SuF02-005 Nov. 3.3 02:18:35.70 -04:31:11.0 24.6 0.863 ? 0.3" NE
    >SuF02-002 Nov. 3.3 02:17:12.24 -04:55:08.7 24.4 0.823 Ia? 0.3" NW
    >SuF02-021 Nov. 3.3 02:18:10.56 -04:40:20.6 24.6 0.69 Ia? 2.9" SSW
    >SuF02-055 Nov. 3.3 02:18:53.20 -04:32:59.2 23.7 0.66 Ia 0.6" N
    >SuF02-082 Nov. 3.3 02:18:40.73 -05:03:44.3 25.3 0.623 Ia? 1.1" NNW
    >SuF02-025 Nov. 3.3 02:16:23.93 -04:49:29.4 24.5 0.606 Ia 0.2" W
    >SuF02-077 Nov. 3.3 02:18:35.15 -04:26:38.9 25.1 0.59 Ia? 0.6" NW
    >SuF02-001 Nov. 3.3 02:17:00.05 -04:58:19.6 23.4 0.57 Ia 0.5" W
    >SuF02-019 Nov. 3.3 02:17:38.08 -05:08:46.8 24.5 0.505 Ia? 0.3" NW
    >SuF02-028 Nov. 3.3 02:16:56.37 -05:00:57.4 24.9 0.347? ? 1.5" SE
    >SuF02-059 Nov. 3.3 02:20:28.06 -04:58:50.3 25.7 0.269 Ia? 0.2" E
    >
    >
    >SCPname 2002 UT R.A. (J2000) Decl. i' host info.
    >SuF02-081 Nov. 3.3 02:20:07.55 -05:08:27.2 25.1 0.0"
    >SuF02-012 Nov. 3.3 02:18:51.59 -04:47:24.8 25.1 0.2" N
    >SuF02-083 Nov. 3.3 02:18:06.22 -05:00:38.1 26.0 0.4" S
    >SuF02-034 Nov. 3.3 02:18:31.21 -05:01:24.4 25.6 0.2" N
    >SuF02-004 Nov. 3.3 02:18:09.01 -04:54:17.9 25.1 0.6" SE
    >SuF02-086 Nov. 3.3 02:17:16.18 -05:06:02.7 26.2 no host
    >SuF02-076 Nov. 3.3 02:16:26.37 -05:04:32.5 26.1 no host
    >SuF02-J01 Nov. 3.3 02:17:45.97 -04:36:46.2 25.2 0.2" W
    >SuF02-051 Nov. 3.3 02:17:27.48 -04:40:45.2 25.4 no host
    >SuF02-057 Nov. 3.3 02:20:13.92 -05:07:36.0 25.6 no host
    >SuF02-056 Nov. 3.3 02:20:00.03 -04:44:20.2 24.3 0.5" SE
    >
    >
    >
    Mamoru,
    Thank you for the updated list. I apologize for missing the last
    meeting due to observing. If something was decided there that I am
    unfamiliar with, please let me know. For example, if you have evidence
    that some of these are in elliptical galaxies, that would make a
    difference in what I say below.

    There seems to be some confusion about what the definition of our
    categories is.
    The classic definition of a Ia is that you see Si in the spectrum. We
    wouldn't see Si or S in the spectrum. The redshifts of most of these
    are high enough that we wouldn't expect to see Si II at 6150 A or S II
    around 5400 A, but we should see Si II at 4000 A. One might expand the
    definition of Ia's to include all SNe in elliptical galaxies, but at z=1
    we can't even be sure of that.

    I would define a "Ia?" as a SN that does not show Si but otherwise shows
    some evidence that it is a Ia. We should only rarely use this category.

    The category "SN" is for the cases where we can see broad lines, but
    can't tell the type.

    We can use the category "I" if we can rule out Type II. Many of the
    ones I list as "SN" below could be converted to "I" if someone goes
    through them and rules out Type II interpretations.

    Here are how I would reclassify some of the supernovae listed above.
    SuF02-007 Ia -> SN If the redshift is uncertain, then the type is
    uncertain.
    SuF02-071 Ia -> SN At that redshift, Ia features do not seem to match.
    SuF02-065 Ia -> SN Lightcurve appears to be inconsistent with Ia
    SuF02-055 Ia -> SN One bump in the spectrum.
    SuF02-037 Ia -> SN One bump in the spectrum.
    SuF02-000 Ia? -> SN Almost all galaxy light.
    SuF02-002 Ia? -> SN Chris says: Wiggles don't seem to match a Ia at this
    redshift.
    SuF02-082 Ia? -> SN Essentially a featureless spectrum.
    SuF02-019 Ia? -> SN Featureless, mainly galaxy light
    SuF02-059 Ia? -> SN How can it be at I=25.7 and z=0.269 and still be
    called Ia?
    SuF02-021 Ia? I don't have the spectrum (it is from the last
    night of Keck), but Saul's notes don't mention a match to a Ia.
    SuF02-077 Ia? I don't have the spectrum, but Saul's notes
    don't mention a match to a Ia.

    Also, the convention is to use a ":" rather than a "?" to denote
    uncertainty on redshift.
    Some of the redshifts that are determined from a fit to the SN spectrum
    may need a ":" as well when we aren't sure of the SN type. I haven't
    looked at these.

    -Andy



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