Ori Fox
University of Virginia
Abstract:
Supernovae light curves typically peak and fade in the course of several
months. Some supernovae , however, exhibit late-time infrared emission
that in some cases can last for several years. These supernovae tend to
be of the Type IIn subclass, which is defined by narrow hydrogen and
helium emission lines arising from a dense, pre-existing circumstellar
medium excited by the supernova radiation. Such a late-time ``IR excess''
with respect to the optical blackbody counterpart typically indicates the
presence of warm dust. The origin and heating mechanism of the dust is
not, however, always well constrained. In this talk, I will explore
several scenarios that explain the observed late-time emission. In
particular, I will discuss the case of the Type IIn SN 2005ip, which has
displayed an ``IR excess'' for over 3 years. The results allow us to
interpret the progenitor system and better understand the late stages of
stellar evolution.
Infrared observations not only are more sensitive to warm dust, but are
also optimized for high redshift targets. To this end, the next
generation of infrared instruments (e.g., JWST) must be sensitive to
extremely faint targets. Infrared detector properties must therefore be
measured to a higher precision. The upcoming Joint Dark Energy Mission
(JDEM), for example, requires the precise measure of the dark energy
equation equation of state, w and w'. To obtain the necessary accuracy,
the mission requires detector characterization measurements to within 2%.
In the final third of my talk, I will discuss a calibration technique
involving ^{55}Fe X-rays that allow us to obtain the necessary accuracy.