SH13B-2441
The NuSTAR Sensitivity to Quiet-Sun Transient Events
Monday, 14 December 2015
Poster Hall (Moscone South)
Andrew Marsh1, David Miles Smith1, Lindsay Glesener2, Iain G Hannah3, Sam Krucker2, Hugh S Hudson2, Brian Grefenstette4 and Kristin Madsen4, (1)University of California Santa Cruz, Santa Cruz, CA, United States, (2)University of California Berkeley, Berkeley, CA, United States, (3)University of Glasgow, Glasgow, United Kingdom, (4)California Institute of Technology, Pasadena, CA, United States
Abstract:
We present the NuSTAR sensitivity to quiet Sun (QS) transient events, which have been seen in wavelengths from UV to soft X-rays. Although not optimized for solar observations, NuSTAR can observe X-ray emission from the Sun with unprecedented sensitivity in the hard X-ray range; this is crucial for detecting individual events in the quiet corona. While NuSTAR has not yet detected any such events, we use QS data from the 01-November-2014 observations (at a GOES-level ~B4) to determine what types of events we could have detected. In particular, we place lower limits on the detectable flare emission measure for isothermal temperatures between 2 – 10 MK. While our sensitivity to date has been limited by noise due to active regions outside the field of view, these limits are still >2 orders of magnitude below the RHESSI detection limits at corresponding temperatures. We expect to increase our sensitivity by at least an order of magnitude with future observations at lower solar flux levels and with fewer active regions on the disk.
