E-Print Archive

There are 3835 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
Statistical Properties of Ribbon Evolution and Reconnection Electric Fields in Eruptive and Confined Flares
Unambiguous Evidence of Filament Splitting-Induced Partial Eruptions
On the Origin of the Double-cell Meridional Circulation in the Solar Convection Zone
Modelling Quasi-Periodic Pulsations in Solar and Stellar Flares
Diffusive transport of energetic electrons in the solar corona: X-ray and radio diagnotics
Plasma evolution within an erupting coronal cavity
Identification of multiple hard X-ray sources in solar flares: A Bayesian analysis of the February 20 2002 event
Flux Rope Breaking and Formation of a Rotating Blowout Jet
On-Orbit Performance of the Helioseismic and Magnetic Imager Instrument onboard the Solar Dynamics Observatory
Two-Phase Heating in Flaring Loops
Evidence For The Magnetic Breakout Model in an Equatorial Coronal-Hole Jet
Spontaneous flux concentrations from the negative effective magnetic pressure instability beneath a radiative stellar surface
Powerful Solar Flares of September 2017: Correspondence Between Parameters of Microwave Bursts and Proton Fluxes near Earth
Evaluation of Applicability of a Flare Trigger Model based on Comparison of Geometric Structures
Coronal hole evolution from multi-viewpoint data as input for a STEREO solar wind speed persistence model
Formation and Dynamics of a Solar Eruptive Flux Tube
The Instruments and Capabilities of the Miniature X-ray Solar Spectrometer (MinXSS) CubeSats
Fine Structures of Solar Radio Type III Bursts and their Possible Relationship with Coronal Density Turbulence
Influence of misalignments on the performance of externally occulted solar coronagraphs. Application to PROBA-3/ASPIICS
Observations of Electron-driven Evaporation during a Flare Precursor

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



© 2003 Solar Physics Group - Montana State University