Open AccessESC and KAIT observations of the transitional Type Ia SN 2004eo
Author(s) -
Pastorello A.,
Mazzali P. A.,
Pignata G.,
Benetti S.,
Cappellaro E.,
Filippenko A. V.,
Li W.,
Meikle W. P. S.,
Arkharov A. A.,
Blanc G.,
Bufano F.,
Derekas A.,
Dolci M.,
EliasRosa N.,
Foley R. J.,
Ganeshalingam M.,
Harutyunyan A.,
Kiss L. L.,
Kotak R.,
Larionov V. M.,
Lucey J. R.,
Napoleone N.,
Navasardyan H.,
Patat F.,
Rich J.,
Ryder S. D.,
Salvo M.,
Schmidt B. P.,
Stanishev V.,
Székely P.,
Taubenberger S.,
Temporin S.,
Turatto M.,
Hillebrandt W.
Publication year - 2007
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1111/j.1365-2966.2007.11700.x
Subject(s) - physics , supernova , light curve , ejecta , astrophysics , luminosity , type (biology) , pair instability supernova , spectral line , astronomy , galaxy , ecology , biology
ABSTRACT We present optical and infrared observations of the unusual Type Ia supernova (SN) 2004eo. The light curves and spectra closely resemble those of the prototypical SN 1992A, and the luminosity at maximum ( M B =−19.08) is close to the average for a Type Ia supernova (SN Ia). However, the ejected 56 Ni mass derived by modelling the bolometric light curve (about 0.45 M ⊙ ) lies near the lower limit of the 56 Ni mass distribution observed in normal SNe Ia. Accordingly, SN 2004eo shows a relatively rapid post‐maximum decline in the light curve [Δ m 15 ( B ) true = 1.46] , small expansion velocities in the ejecta and a depth ratio Si ii λ5972/Si ii λ6355 similar to that of SN 1992A. The physical properties of SN 2004eo cause it to fall very close to the boundary between the faint, low‐velocity gradient and high‐velocity gradient subgroups proposed by Benetti et al. Similar behaviour is seen in a few other SNe Ia. Thus, there may in fact exist a few SNe Ia with intermediate physical properties.