The Optical/Near-Infrared Light Curves of SN 2002ap for the First 140 Days after Discovery

Astrophysics, abstract
astro-ph/0304010

From: Hiroyuki Tomita <tomita@aladdin.mtk.nao.ac.jp>

Date: Tue, 1 Apr 2003 03:41:16 GMT   (156kb)

Authors:
Y. Yoshii,
H. Tomita,
Y. Kobayashi,
J. Deng,
K. Maeda,
K. Nomoto,
P. A. Mazzali,
H. Umeda,
T. Aoki,
M. Doi,
K. Enya,
T. Minezaki,
M. Suganuma,
B. A. Peterson

Comments: 15 pages, 6 figures, quality of figure1 is reduced for smaller
filesize, accepted for publication in ApJ

Supernova (SN) 2002ap in M74 was observed in the $UBVRIJHK$ bands for the
first 40 days following its discovery (2002 January 29) until it disappeared
because of solar conjunction, and then in June after it reappeared. The
magnitudes and dates of peak brightness in each band were determined. While the
rate of increase of the brightness before the peak is almost independent of
wavelength, the subsequent rate of decrease becomes smaller with wavelength
from the $U$ to the $R$ band, and is constant at wavelengths beyond $I$. The
photometric evolution is faster than in the well-known “hypernovae”
SNe~1998bw and 1997ef, indicating that SN 2002ap ejected less mass. The
bolometric light curve of SN 2002ap for the full period of observations was
constructed. The absolute magnitude is found to be much fainter than that of SN
1998bw, but is similar to that of SN 1997ef, which lies at the faint end of the
hypernova population. The bolometric light curve at the early epochs was best
reproduced with the explosion of a C+O star that ejects $2.5~M_sun$ with
kinetic energy $E_{
m K}=4 imes 10^{51}~{
m ergs}$. A comparison of the
predicted brightness of SN 2002ap with that observed after solar conjunction
may imply that $gamma$-ray deposition at the later epochs was more efficient
than in the model. This may be due to an asymmetric explosion.

References and citations for this submission:

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