E-Print Archive

There are 4594 abstracts currently viewable.


Search:

Advanced Search
Options
Main Page Add New E-Print Submitter
Information
Feedback
News Help/FAQ About Preferences
Manage Key Phrase
Notification
First NuSTAR Limits on Quiet Sun Hard X-Ray Transient Events View all abstracts by submitter

Amir Caspi   Submitted: 2017-11-22 16:58

We present the first results of a search for transient hard X-ray (HXR) emission in the quiet solar corona with the Nuclear Spectroscopic Telescope Array (NuSTAR) satellite. While NuSTAR was designed as an astrophysics mission, it can observe the Sun above 2 keV with unprecedented sensitivity due to its pioneering use of focusing optics. NuSTAR first observed quiet Sun regions on 2014 November 1, although out-of-view active regions contributed a notable amount of background in the form of single-bounce (unfocused) X-rays. We conducted a search for quiet Sun transient brightenings on time scales of 100 s and set upper limits on emission in two energy bands. We set 2.5-4 keV limits on brightenings with time scales of 100 s, expressed as the temperature T and emission measure EM of a thermal plasma. We also set 10-20 keV limits on brightenings with time scales of 30, 60, and 100 s, expressed as model-independent photon fluxes. The limits in both bands are well below previous HXR microflare detections, though not low enough to detect events of equivalent T and EM as quiet Sun brightenings seen in soft X-ray observations. We expect future observations during solar minimum to increase the NuSTAR sensitivity by over two orders of magnitude due to higher instrument livetime and reduced solar background.

Authors: Andrew J. Marsh, David M. Smith, Lindsay Glesener, Iain G. Hannah, Brian W. Grefenstette, Amir Caspi, Säm Krucker, Hugh S. Hudson, Kristin K. Madsen, Stephen M. White, Matej Kuhar, Paul J. Wright, Steven E. Boggs, Finn E. Christensen, William W. Craig, Charles J. Hailey, Fiona A. Harrison, Daniel Stern, William W. Zhang
Projects: NuSTAR,RHESSI,Yohkoh-SXT

Publication Status: Published -- Marsh, A. J., et al. 2017, ApJ, 849, 131; DOI 10.3847/1538-4357/aa9122
Last Modified: 2017-11-25 10:03
Go to main E-Print page  Super-Flaring Active Region 12673 Has One of the Fastest Magnetic Flux Emergence Ever Observed  Solar-wind predictions for the Parker Solar Probe orbit  Edit Entry  Download Preprint  Delete Entry 

Key
Go to main E-Print pageGo to main E-Print page.
Previous AbstractPrevious Abstract.
Next AbstractNext Abstract.
Download PreprintDownload Preprint.
Submitter's HomepageSubmitters Homepage.
Edit EntryEdit Entry.
View All Abstracts By SubmitterView all abstracts by submitter.
Delete AbstractDelete abstract.

Latest Entries
Repeated Type III Burst Groups Associated with a B-Class Flare and a Narrow-Width CME
Separating the effects of earthside and far side solar events. A case study.
Deciphering The Slow-rise Precursor of a Major Coronal Mass Ejection
Three-dimensional Turbulent Reconnection within Solar Flare Current Sheet
Sequential Remote Brightenings and Co-spatial Fast Downflows during Two Successive Flares
A Model for Confined Solar Eruptions Including External Reconnection
The eruption of a magnetic flux rope observed by Solar Orbiter and Parker Solar Probe
Comprehensive radiative MHD simulations of eruptive flares above collisional polarity inversion lines
An Anisotropic Density Turbulence Model from the Sun to 1 au Derived From Radio Observations
Comparison of damping models for kink oscillations of coronal loops
On the three-dimensional relation between the coronal dimming, erupting filament and CME. Case study of the 28 October 2021 X1.0 event
Polarisation of decayless kink oscillations of solar coronal loops
CME Propagation Through the Heliosphere: Status and Future of Observations and Model Development
30-min Decayless Kink Oscillations in a Very Long Bundle of Solar Coronal Plasma Loops
The Role of High-Frequency Transverse Oscillations in Coronal Heating
ARTop: an open-source tool for measuring Active Region Topology at the solar photosphere
Spectral Observations and Modeling of a Solar White-light Flare Observed by CHASE
New cases of super-flares on slowly rotating solar-type stars and large amplitude super-flares in G- and M-type main-sequence stars
Constraints on the variable nature of the slow solar wind with the Wide-Field Imager on board the Parker Solar Probe
Prediction of short stellar activity cycles using derived and established empirical relations between activity and rotation periods

Related Pages
MSU Solar Physics.
Max Millennium Science Mail Archive.
Max Millennium Message of the Day Mail Archive.
Max Millennium Flare Catalog

Archive Maintainer
Alisdair Davey



© 2000-2020 Solar Physics Group - Montana State University