ﻻ يوجد ملخص باللغة العربية
We report optical and infrared spectroscopic observations of the Type Ia SN 1999ee and the Type Ib/c SN 1999ex, both of which were hosted by the galaxy IC 5179. For SN 1999ee we obtained a continuous sequence with an unprecedented wavelength and temporal coverage beginning 9 days before maximum light and extending through day 42. Before maximum light SN 1999ee displayed a normal spectrum with a strong Si II 6355 absorption, thus showing that not all slow-declining SNe are spectroscopically peculiar at these evolutionary phases. A comparative study of the infrared spectra of SN 1999ee and other Type Ia supernovae shows that there is a remarkable homogeneity among the Branch-normal SNe Ia during their first 60 days of evolution. SN 1991bg-like objects, on the other hand, display spectroscopic peculiarities at infrared wavelengths. SN 1999ex was characterized by the lack of hydrogen lines, weak optical He I lines, and strong He I 10830,20581, thus providing an example of an intermediate case between pure Ib and Ic supernovae. We conclude therefore that SN 1999ex provides first clear evidence for a link between the Ib and Ic classes and that there is a continuous spectroscopic sequence ranging from the He deficient SNe Ic to the SNe Ib which are characterized by strong optical He I lines.
We present contemporary infrared and optical spectroscopic observations of the type IIn SN 1998S for the period between 3 and 127 days after discovery. In the first week the spectra are characterised by prominent broad emission lines with narrow peak
On 2017 March 11, the DLT40 Transient Discovery Survey discovered SN 2017cbv in NGC5643, a Type 2 Seyfert Galaxy in the Lupus Constellation. SN 2017cbv went on to become a bright Type Ia supernova, with a $V_{max}$ of 11.51 $pm$ 0.05 mag. We present
Optical and near-infrared light curves of the Type IIn supernova 1999el in NGC 6951 are presented. A period of 220 days (416 days in the near-infrared) is covered from the first observation obtained a few days before maximum light. Spectroscopic obse
We analyze the complex level structure of ions with many-valence-electron open [Kr] 4$d^textrm{m}$ sub-shells ($textrm{m}$=7-4) with ab initio calculations based on configuration-interaction many-body perturbation theory (CI+MBPT). Charge-state-resol
We present optical and near-infrared (NIR) photometry and spectroscopy of the Type IIb supernova (SN) 2011dh for the first 100 days. We complement our extensive dataset with SWIFT ultra-violet (UV) and Spitzer mid-infrared (MIR) data to build a UV to