Supernovae searh at intermediate z
I. Searh and rst spetrosopi analysis
A. Balastegui (1), P. Ruiz-Lapuente (1), G. Altavilla (1),
J. Mendez (1,2), S. Benetti (3), M. Irwin (4), K. Shamanahe (5),
C. Balland (6,7), R. Pain (5), N. Walton (4)
1) Department of Astronomy, CER for Astrophysis, Partile Physis
and Cosmology, Univerisitat de Barelona, Diagonal 647, 08028,
Barelona, Spain
2) Isaa Newton Group of Telesopes, 38700 Santa Cruz de La Palma,
Islas Canarias, Spain
3) INAF-Astronomial Observatory of Padova, violo dell'Osservatorio
5, 35122 Padova, Italy
4) Institute of Astronomy, University of Cambridge, Madingley Road,
Cambridge. CB3 0HA, United Kingdom
5) LPNHE-IN2P3-CNRS-Universites Paris 6 et Paris 7, 4 plae
Jussieu, 75252 Paris Cedex 05 Frane
atiment 121, Universite Paris 11,
6) Institut d'Astrophysique Spatiale, B^
91405 Orsay Cedex, Frane
7) Universite Paris Sud, IAS-CNAS, B^
atiment 121, Orsay Cedex,
Frane
We present 8 supernovae disovered as part of the International
Time Programme (ITP) projet \
and from Supernovae, and the physis
of Supernovae Explosions" at the European Northern Observatory (ENO). The
0 4)
objetive is to inrease the sample of intermediate redshift (0 1
Supernovae (SNe) Ia.
Abstrat.
:
1.
Intermediate
z
< z
<
:
Supernovae
Though SNe Ia are extensively used in osmologial studies as distane indiator, the urrent understanding of their explosion mehanism is still inomplete.
The empirial luminosity alibration is ahieved at low redshift while there is a
small sample of SNe at medium z to onnet the low z with the very high z SN
sample. The aim of our projet is to ll preisely this gap between the loal and
the high-z sample and to provide detailed spetrosopi and photometri data
in order to improve the knowledge on SNe. Our observations led to the onrmation of 6 SNe Ia in the range 0:033 < z < 0:329, one of them being a peuliar
sub-luminous objet, and 2 SNe II, both at z 0:14 (see Table 1). The rest of
the disovered objets were QSOs and ative galaxies. The searh was performed
with the Wide Field Camera (WFC) at the Isaa Newton Telesope (INT), La
Palma. Detetion of the SN andidates was followed by spetrosopi identiation performed with the Intermediate dispersion Spetrograph and Imaging
System (ISIS) mounted at the 4.2m William Hershel Telesope (WHT). The
onrmed SNe were then followed photometrially through various ENO telesopes.
1
2
Balastegui et al.
Table 1.
SN
name
2002li
2002lj
2002lp
2002lq
2002lr
2002lk
2002ln
2002lo
Observ.
date
Jun. 10
Jun. 11
Jun. 10
Jun. 10
Jun. 10
Jun. 10
Jun. 10
Jun. 11
Summary of observations.
R.A.(2000.0)
hh mm ss
15:59:03.08
16:19:19.65
16:40:11.45
16:40:28.83
22:33:12.59
16:06:55.92
16:39:24.93
16:39:56.42
Æ (2000.0)
Æ
'"
+54:18:16.0
+53:09:54.2
+42:28:30.2
+41:14:09.1
+01:05:56.7
+55:28:18.2
+41:47:29.0
+42:19:20.5
z
0.329
0.180
0.144
0.269
0.255
0.033
0.138
0.136
SN
Type
Ia
Ia
Ia
Ia
Ia
Ia pe.
SN II
SN II
Comments
& best mathing nearby SN
1 week before maximum, 1990N
1 week past maximum, 1994D
around maximum, 1981B
1 week before maximum, 1990N
10 days past maximum, 1994D
a few days before maximum, 1991bg
2 weeks past maximum, 1999em
1 month past maximum, 1999em
The omparison of our intermediate z SN spetra with high-signal-to-noise ratio
spetra of nearby SNe has not revealed signiant dierenes. In partiular we
found a good math with nearby SN spetra for all our objets but peuliar SN
2002lk (see Table 1 and Fig. 1).
This result is in the same diretion of the ones obtained from high-z SNe studies (Riess et al. 1998; Perlmutter et al. 1998; Perlmutter et al. 1999). Further
results of the spetrosopi analysis will be presented in a forthoming paper.
Figure 1. Comparison of SN 2002lj smoothed spetrum with that of SN
1994D 7 days past maximum (Patat et al. 1996) (left panel) and with a template at the same epoh (Nobili et al. 2003) (right panel).
Referenes
Nobili, S., Goobar, A., Knop, R. et al. 2003, A&A, 404, 901
Patat, F., Benetti, S., Cappellaro, E. et al. 1996, MNRAS, 278, 111
Perlmutter, S. et al 1998, Nature, 391, 51
Perlmutter, S. et al. 1999, ApJ, 517, 565
Riess, A. G. et al. 1998, AJ, 116, 1009