All Figures

Figure 1: A finding chart centered on SN 2000fr (C00-008). North is up and East is to the left. The candidate is marked with a cross and bright pivot stars are marked with either a box or a hexagon. Fainter pivot stars are circled and labelled alphabetically. The pivot star that was used during the acquisition is recorded in Table 3. The finding charts of other candidates are available in the Appendix.

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In the text

	Figure 2: A redshift histogram of the candidates.
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In the text

Figure 3: A spectrum of SN 2000fr, a SN Ia at z=0.543 with unambiguous detection of Si II at 4000 Å. In the upper spectrum, the unbinned spectrum of the candidate is plotted in the observer's frame and is uncorrected for host galaxy light. Night sky subtraction residuals are marked with the letters "NS'' and telluric absorption features are marked with the symbol . In the lower spectrum, contamination from the host is removed and the spectrum is rescaled and rebinned by 20 Å. This spectrum is plotted in black and it is plotted in both the rest frame ( lower axis) and the observer's frame ( upper axis). For comparison, the best fitting nearby supernova is plotted in blue. SN 2000fr was first identified as a SN Ia in a very early spectrum that was taken with LRIS on the KeckII telescope on 2001 May 4th and was subsequently observed again with FORS1. The FORS1 spectrum has one of the highest S/N ratios of all securely identified supernovae in this paper. SN 2000fr was followed in the J-band with ISAAC (Nobili 2004) and in the R- and I-bands with HST and ground-based telescopes (Knop et al. 2003). The J-band observations, which corresponds to the rest-frame I-band, show a clear second maximum about 30 days after the first maximum. A spectrum of the host galaxy (not shown here) shows emission in [OII] and [OIII] as well as Balmer absorption lines.

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In the text

Figure 4: The percentage increase versus the signal-to-noise ratio for candidates that were brighter than I=24.7 at the time of discovery. Candidates that were classified as Ia (Ia*) are plotted with solid circles (squares), C02-031 - a possible SN II - is plotted as a star and unclassified candidates are plotted with open circles. Candidates from the CFHT 2002 search are highlighted with large circles. Candidates with arrows have percentage increases that are greater than 1000%, which means that the host was considerably fainter than the candidate and perhaps undetected. The dashed line marks the region where the percentage increase is 25% or less. Candidates in this region are difficult to classify spectrally.

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In the text

Figure A.1: Above, a finding chart centered on SN 2001gl (S01-004), an unclassified candidate at an unknown redshift, and below, the spectrum. This unusual candidate has very broad spectral features; however, it was not possible to match this candidate with any of the supernovae in our nearby catalog. No host was detectable in the reference image, and the search images, which were taken 16 and 20 days after the reference image, indicate that the candidate was real and stationary, implying that it was not a solar system body. The spectrum was taken 21 days after the reference images.


In the text

Figure A.2: Above, a finding chart centered on SN 2001gm (S01-005), a SN Ia at z=0.478, and below, the spectrum. Although a bright night sky line contaminates the 4000 Å region, the Si II feature at 4000 Å is clearly detected. A separate spectrum of the host (not shown here) shows weak [OII] emission.


In the text

Figure A.3: Above, a finding chart centered on SN 2001go (S01-007), a SN Ia at z=0.552, and below, the spectrum. This candidate was observed at three epochs. The initial confirmation spectrum (shown here) was taken on 2001 May 21. The Si II feature at 4000 Å feature can be clearly seen. Additional deeper spectra (not shown here) were taken 6 and 37 observer-frame days later (Garavini et al., in preparation).


In the text

Figure A.4: Above, a finding chart centered on SN 2001gr (S01-017), a SN Ia at z=0.540, and below, the spectrum. Although Si II feature at 4000 Å is not clearly detected in this candidate, the data are significantly better fit with SN Ia spectra than with the spectra of other types.


In the text

Figure A.5: Above, a finding chart centered on SN 2001gs (S01-028), an unclassified candidate at z=0.658, and below, the spectrum. This is a faint candidate on a bright host that was observed during a period of relatively poor seeing. The percentage increase in the flux was only 27%, so most of the light in the spectrum is from the host, which has several Balmer absorption lines.


In the text

Figure A.6: Above, a finding chart centered on SN 2001gu (S01-031), a SN Ia at z=0.777, and below, the spectrum. The host shows CaII H and K absorption lines and no detectable [OII] emission which suggests an early-type host. Since the Si II feature at 4000 Å is weak and contaminated by the H and K lines of the host, the classification is based on the fit. The redshift of the fit was constrained to that of the host. The wavelength coverage of the best matching nearby SN Ia, SN 1999bp, is restricted to rest frame wavelengths that are greater than 3000 Å, so the comparison is limited to these wavelengths.


In the text

Figure A.7: Above, a finding chart centered on SN 2001gw (S01-033), a SN Ia at z=0.363, and below, the spectrum. In addition to the Si IIfeature at 4000 Å, the Si II feature at 6150 Å is also visible. The redshift is derived from an [OII] emission line in the spectrum of the host galaxy (not shown here).


In the text

Figure A.8: Above, a finding chart centered on SN 2001gy (S01-036), a SN Ia at z=0.511, and below, the spectrum. The Si II feature at 4000 Å is clearly detected.


In the text

Figure A.9: Above, a finding chart centered on S01-037, and below, the spectrum. Neither the classification nor the redshift of this candidate is known. The spectrum shows a strong blue continuum which is characteristic of type II supernovae before maximum light; however, with neither a redshift nor clear spectral features, a classification cannot be made. The candidate was detected on search images that were taken on different dates and is stationary, so it is not an asteroid nor an artifact.


In the text

Figure A.10: Above, a finding chart centered on SN 2001ha (S01-054), a SN Ia at z=0.58, and below, the spectrum. There are no spectral features from the host and a host is not visible in the reference image, so the redshift is determined from the fit. The Si II feature at 4000 Å is clearly detected.


In the text

Figure A.11: Above, a finding chart centered on SN 2001hc (S01-065), a SN Ia at z=0.35, and below, the spectrum. This relatively nearby candidate has Si II at 6150 Å, S II at 5400 Å, and Si II at 4000 Å. There are no spectral features from the host, so the redshift is determined from the fit. In the reference image, a very faint host is visible.


In the text

Figure A.12: Above, a finding chart centered on SN 2002fd (S02-000), a SN Ia at z=0.279, and below, the spectrum. The Si II feature at 4000 Å is clearly detected, but the Si II feature at 6150 Å is relatively weak.


In the text

Figure A.13: Above, a finding chart centered on S02-001, an unclassified candidate at z=1.424, and below, the spectrum. A single strong line and a featureless continuum. Given the width and shape of the line and the lack of other lines in the wavelength range covered by the spectra, the line is identified as the [OII] doublet at 3727 Å. It is unlikelythat the line is Ly at z>5 because the characteristic asymmetry of Ly in galaxies at z>5 (Stern et al. 2000) and the jump in the continuum across the line are not evident in these spectra. Nor is the line likely to be , as neither nor [OIII] are detected. The equivalent width of the line is greater than 50 Å  so the host galaxy would be classified as an emission line galaxy (ELG) if the line were (Kniazev et al. 2004). In ELGs, is typically three times weaker than and the strengths of [OIII] and are roughly equivalent. Given the strength of the detected line in these spectra, both [OIII] and should have been detected if the line was .


In the text

Figure A.14: Above, a finding chart centered on SN 2002fe (S02-002), a SN Ia* at z=1.086, and below, the spectrum. The profile of the line that we have identified as [OII] is affected by a nearby bright night sky line; however, the line is clearly detected in the 2-dimensional spectrum. This line, together with the probable detection of the H and K Ca II lines in the host, enables us to measure a secure redshift. The signal-to-noise ratio of the spectrum is relatively low and the Si II feature at 4000 Å is not detected, so the the classification is qualified with an asterisk. In some nearby SNe Ia that are observed one to two weeks before maximum light, the Si II feature is absent. The best fit nearby SN Ia, SN 1999ee, shows no Si II at 4000 Å.


In the text

Figure A.15: Above, a finding chart centered on S02-025 and below, the spectrum. This candidate has a blue continuum with no significant spectral features. It has neither a classification nor a redshift.


In the text

Figure A.16: Above, a finding chart centered on SN 2002fg (S02-075), a SN Ia* at z=0.78, and below, the spectrum. Since the Si II feature at 4000 Å is not clearly detected in this candidate and since there are no spectral features from the host, the classification and the redshift are derived from the fit. The candidate was observed several weeks after it was discovered, so it is likely that the spectrum was taken past maximum light. The best matching nearby SN Ia is SN 1999bm at 6 days past maximum light. The signal-to-noise ratio is also relatively low and the SiII feature at 4000 Å is not detected, so the classification is qualified with an asterisk.


In the text

Figure A.17: Above, a finding chart centered on SN 2002fr (C02-016), an unclassified candidate that might be at z=0.303, and below, the spectrum. This candidate has a very well sampled light curve (7 points), which shows a dramatic rise over the first 5 days. The spectrum is dominated by slightly irregular blue continuum and there is a very weak line which would put the host at z=0.303 if the line is identified as [OII].


In the text

Figure A.18: Above, a finding chart centered on SN 2002fm (C02-028), an unclassified candidate at z=0.448, and below, the spectrum. The percentage increase in this candidate was very small, only 13%, and the spectrum is dominated by the light from the host galaxy. However, there is excess flux at 6600 Å and 5600 Å that might be from a supernova. Unfortunately, an acceptable fit with a nearby SN Ia was not possible. In such cases, the fit depends critically on how well the galaxy template matches the spectrum of the host galaxy. Relatively small errors can leave significant residuals which can make the matching difficult. The most secure way of fitting this candidate will be take a spectrum of the host after the supernova has faded. The candidate is offset from the center of the host and the light curve is well sampled with four points before maximum light and four points after maximum light.


In the text

Figure A.19: Above, a finding chart centered on SN 2002fp (C02-030), an unclassified candidate at z=0.352, and below, the spectrum. The host galaxy has emission lines in [OIII] and . The continuum is blue and, at this signal-to-noise ratio, featureless. This candidate might be a SN II, since the pre-maximum spectra of SNe II are generally featureless and blue; however, without clear features in the continuum, we cannot assign a classification.


In the text

Figure A.20: Above, a finding chart centered on C02-031, a possible type II supernova at z=0.541 and below, the spectrum. The host galaxy has emission lines in [OIII], and . The tentative classification is based on the blue continuum and a weak H-beta line with a P-Cygni profile.


In the text

Figure A.21: Above, a finding chart centered on C02-034, an unclassified candidate at z=0.243, and below, the spectrum. The host galaxy has emission lines in , and [OII]. The calcium H and K absorption lines are also visible.


In the text

Figure A.22: Above, a finding chart centered on SN 2002gi (T02-015), a SN Ia at z=0.912, and below, the spectrum. The Si II 4000 Å feature is clearly detected in this high redshift candidate. This SN Ia has the highest redshift of all securely classified SNe Ia that were observed with FORS1.


In the text

Figure A.23: Above, a finding chart centered on SN 2002gj (T02-028), a SN Ia* at z=0.45, and below, the spectrum. From the spectrum alone, this candidate can be matched with either a SN Ia at 10 days after maximum light or with a SN Ic near maximum light, so the classification is qualified with an asterisk. The time of maximum that is derived from the light curve shows that the spectrum was taken about 10 rest frame days after maximum light, so the the candidate is very likely to be a SN Ia.


In the text

Figure A.24: Above, a finding chart centered on SN 2002gk (T02-029), a SN Ia at z=0.212, and below, the spectrum. This SN Ia has the lowest redshift and the spectrum has the highest signal-to-noise ratio of all candidates. Si II at 4000 Å and 6150  Å and S II at 5400 Å are all clearly detected.


In the text

Figure A.25: Above, a finding chart centered on SN 2002gl (T02-030), a SN Ia at z=0.510, and below, the spectrum. Si II at 4000 Å and S II at 5400 Å are clearly detected in this candidate.


In the text

Figure A.26: Above, a finding chart centered on T02-047, a probable supernova at z=0.489, and below, the spectrum. The spectrum of the host was taken a couple of months after the candidate had faded and is rich in emission lines. Although a spectrum of the candidate was not obtained, the well-sampled light curve indicates that it is probably a supernova.


In the text

Figure A.27: Above, a finding chart centered on SN 2002kq (SuF02-002), an unclassified candidate at z=0.823, and below, the spectrum. This candidate was photometrically monitored and it has a supernova-like light curve.


In the text

Figure A.28: Above, a finding chart centered on SuF02-005, an unclassified candidate at z=0.863, and below, the spectrum. This candidate has an extremely broad bump at 8500 Å. Since we observed the pivot star (object "A'' in the finding chart) simultaneously with the candidate, we can use the flux-calibrated spectrum of the pivot star to check the calibration procedure. The flux-calibrated spectrum of star A does not have the broad feature that can be seen in the candidate, so the broad feature at 8500 Å is real.


In the text

Figure A.29: Above, a finding chart centered on SuF02-007 and below, the spectrum. The binned spectrum shows broad features that are consistent with a SN Ia at z=1.16; however, the signal-to-noise ratio is too low for this candidate to be classified as a SN Ia from the spectrum alone. This candidate was photometrically monitored and has a supernova-like light curve.


In the text

Figure A.30: Above, a finding chart centered on SN 2002lc (SuF02-012) and below, the spectrum. The binned spectrum shows broad SN Ia like features which are consistent with a SN Ia at z=1.3, however the signal-to-noise ratio is too small for a spectral classification. Hence, from the VLT spectrum alone it cannot be classified. However, SN 2002lc was also observed with FOCAS on Subaru, and the spectrum also shows similar broad features (Yasuda et al. in preparation). When added with the VLT data, a possible match with a SN Ia at z=1.26 emerges. Furthermore, a spectrum of SN 2002lc was also taken with the ACS grism on HST. The reduced ACS spectrum shows the same broad features as the ground-based data. This candidate was photometrically monitored and has a supernova-like light curve.


In the text

Figure A.31: Above, a finding chart centered on SN 2002kn (SuF02-017), a SN Ia* at z=1.03, and below, the spectrum. The host galaxy is approximately three magnitudes fainter than the candidate, so the fraction of host galaxy light is set to zero in the fit. Since the Si II feature at 4000 Å is not clearly detected in this candidate and since there are no spectral features from the host, the redshift and the classification are derived from the fit. The spectrum can be fit equally well with a SN Ic, so the classification is qualified with an asterisk.


In the text

Figure A.32: Above, a finding chart centered on SN 2002km (SuF02-025), a SN Ia at z=0.606, and below, the spectrum. The Si II line at 4000 Å is clearly detected. There is a hint of the Si II line at 6150 Å.


In the text

Figure A.33: Above, a finding chart centered on SuF02-026 and below, the spectrum. This candidate has two unidentified emission lines with differing line profiles and spatial morphologies. The line at is unresolved while the line at is spatially and kinematically resolved into three components. This candidate was photometrically monitored and it has a supernova-like light curve.


In the text

Figure A.34: Above, a finding chart centered on SN 2002kn (SuF02-028), an unclassified candidate at z=0.347, and below, the spectrum. This candidate is dominated by host galaxy light. It was photometrically monitored and it has a supernova-like light curve.


In the text

Figure A.35: Above, a finding chart centered on SuF02-051, an unclassified candidate at an unknown redshift, and below, the spectrum. The spectrum is a featureless, slightly blue continuum. This candidate was photometrically monitored and it has a supernova-like light curve.


In the text

Figure A.36: Above, a finding chart centered on SN 2002kr (SuF02-060), a SN Ia* at z=1.063, and below, the spectrum. The redshift is determined from H and K Ca II absorption lines in the host. There is a hint of [OII] emission, but this is uncertain as the [OII] line at this redshift lies very close to atmospheric A band. The percentage increase was only 25%, so the spectrum is dominated by the host, which means that the host subtracted spectrum is sensitive to the host spectrum used in the fit. Hence, the classification is qualified with an asterisk. SN 2002kr was also observed with the ACS grism on HST and the GMOS spectrograph on Gemini. Both the Gemini and ACS show the same broad features as the VLT data.


In the text

Figure A.37: Above, a finding chart centered on SN 2002ks (SuF02-065), a SN Ia at z=1.181, and below, the spectrum. The Si II feature at 4000 Å is clearly detected. This SN Ia has the highest redshift of all securely classified SNe Ia that were observed with the ESO VLT.


In the text

Figure A.38: Above, a finding chart centered on SuF02-081, an unclassified candidate at z=1.478 and below, the spectrum. A single strong line and a featureless red continuum. Like S02-001 and SN 2003kx we identify this line as the [OII] doublet at 3727 Å. This candidate was photometrically monitored and it has a light curve that is too narrow for it to be a SN Ia.


In the text

Figure A.39: Above, a finding chart centered on SN 2003kx (SuF02-083), an unclassified candidate at z=1.272, and below, the spectrum. A single strong line and a featureless continuum. Like S02-001 and SuF02-083, we identify this line as the [OII] doublet at 3727 Å. This candidate was photometrically monitored and it has a supernova-like light curve.


In the text