SH31D-03
NuSTAR X-ray observations of small flares and non-flaring active regions
Wednesday, 16 December 2015: 08:30
2011 (Moscone West)
Iain G Hannah1, Brian Grefenstette2, David Miles Smith3, Andrew Marsh3, Lindsay Glesener4, Sam Krucker4, Hugh S Hudson4, Stephen White5, Kristin Madsen2, Amir Caspi6, Julia Vogel7 and Albert Shih8, (1)University of Glasgow, Glasgow, United Kingdom, (2)California Institute of Technology, Pasadena, CA, United States, (3)University of California Santa Cruz, Santa Cruz, CA, United States, (4)University of California Berkeley, Berkeley, CA, United States, (5)AFRL, Kirtland AFB, NM, United States, (6)Southwest Research Institute Boulder, Boulder, CO, United States, (7)Lawrence Livermore National Laboratory, Livermore, CA, United States, (8)NASA GSFC, Greenbelt, MD, United States
Abstract:
We present imaging spectroscopy of the Sun with the NuSTAR hard X-ray (HXR) telescope, an astrophysics mission that uses focusing optics to directly image X-rays between ~2-80 keV. Although not optimized for solar observations, NuSTAR’s high sensitivity can probe previously inaccessible X-ray emission from the Sun – crucial for searching for high temperature and non-thermal emission from “non-flaring” active regions. We present analysis of the first NuSTAR solar observations, that began in late 2014 and continued through 2015. These include using its imaging spectroscopy capabilities to derive the thermal characteristics of several “non-flaring” active regions, providing limits to the high temperature emission. We also show NuSTAR observations of several small microflares that were also observed by Hinode/XRT (in multiple thicker filters sensitive to higher temperatures) and RHESSI. This combination of three separate X-ray telescopes provides a broad observational characterization of active region heating by these very small microflares.
