ﻻ يوجد ملخص باللغة العربية
We present multi-band photometric and optical spectroscopic observations of SN2007ax, the faintest and reddest Type Ia supernova (SNIa) yet observed. With M_B = -15.9 and (B-V)max = 1.2, this SN is over half a magnitude fainter at maximum light than any other SNIa. Similar to subluminous SN2005ke, SN2007ax also appears to show excess in UV emission at late time. Traditionally, Delta-m_15(B) has been used to parameterize the decline rate for SNeIa. However, the B-band transition from fast to slow decline occurs sooner than 15 days for faint SNeIa. Therefore we suggest that a more physically motivated parameter, the time of intersection of the two slopes, be used instead. Only by explaining the faintest (and the brightest) supernovae, we can thoroughly understand the physics of thermonuclear explosions. We suggest that future surveys should carefully design their cadence, depth, pointings and follow-up to find an unbiased sample of extremely faint members of this subclass of faint SNeIa.
We present early phase observations in optical and near-infrared wavelengths for the extremely luminous Type Ia supernova (SN Ia) 2009dc. The decline rate of the light curve is $Delta m_{15}(B)=0.65pm 0.03$, which is one of the slowest among SNe Ia.
Observations of the recent SN 1991bg in the elliptical galaxy NGC 5490 show that this objects closely resembles, both photometrically and spectroscopically, the faint SNIa 1991bg. The two objects have similar light curves, which do not show seconda
We present Hubble Space Telescope observations and photometric measurements of the Type Ia supernova (SN Ia) SN 2013aa 1500 days after explosion. At this epoch, the luminosity is primarily dictated by the amounts of radioactive ${}^{57}textrm{Co}$ an
We examine three SNe Type Ia datasets: Union2.1, JLA and Panstarrs to check their consistency using cosmology blind statistical analyses as well as cosmological parameter fitting. We find that Panstarrs dataset is the most stable of the three to chan
We present a study of the peculiar Type Ia supernova 2001ay (SN 2001ay). The defining features of its peculiarity are: high velocity, broad lines, and a fast rising light curve, combined with the slowest known rate of decline. It is one magnitude dim