Secondary Maximum in the Near-Infrared Lightcurves of Type Ia Supernovae

We undertake a theoretical study of the near-infrared (NIR) lightcurves of Type Ia supernovae (SNe Ia). In these bands, the lightcurves are distinguished by a secondary maximum occurring roughly 20 to 30 days after the initial one. Using time-dependent multi-group radiative transfer calculations, we calculate the UBVRIJHK-band lightcurves of model SN Ia ejecta structures. Our synthetic NIR lightcurves show distinct secondary maxima, and provide favorable fits to observed SNe Ia. We offer a detailed explanation of the origin of the NIR secondary maximum, which is shown to relate directly to the ionization evolution of iron group elements in the ejecta. This understanding provides immediate intuition into the dependence of the NIR lightcurves on the physical properties of the ejecta, and in particular explains why brighter supernovae have a later and more prominent secondary maximum. We demonstrate the dependence of the NIR lightcurves on the mass of 56Ni, the degree of 56Ni mixing, the mass of electron caputre elements, the progenitor metallicity, and the abundance of intermediate mass elements (especially calcium). The secondary maximum is shown to be a valuable diagnostic of these important physical parameters. The models further confirm that SNe Ia should be excellent standard candles in the NIR, with a dispersion < 0.2 mag even when the physical properties of the ejecta are varied widely. This study emphasizes the consummate value of NIR observations in probing the structure of SNe Ia and in furthering their cosmological utility.Comment: 14 pages; ApJ accepte

Theoretical aspects of coping strategies study

In article based on a thorough analysis of classical and modern foreign and domestic literature examines the notion of coping strategies, approaches to the understanding of coping. Theoretically proved that coping is an individual way to interact with the situation according to its own logic, psychological capabilities and its importance in human life, the level of development of coping resources provides a successful adaptation to stress. From the analysis of theoretical literature, we saw that the uncertainty of events to humans might arise from objectively defi ned parameters of the situation and its subjective interpretation that is associated with the personal characteristics of the person, lack of experience or skills in this type of life events. The signifi cance of the research question in a pedagogical context is to help the teenager to better adapt to the demands of the situation, allowing him to possess her, to repay the action stressful situation, creative process and become an active subject