Hot Dust! Late-Time Infrared Emission From Supernovae (and a Quick
Summary of the Next Generation of Infrared Detectors)

Ori Fox
University of Virginia


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.