E-Print Archive

There are 3945 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
Forward Modeling Transient Brightenings and Microflares around an Active Region Observed with Hi-C  

Adam Kobelski   Submitted: 2014-08-25 18:25

Small scale flare-like brightenings around active regions are among the smallest and most fundamental of energetic transient events in the corona, providing a testbed for models of heating and active region dynamics. In a previous study, we modeled a large collection of these microflares observed with Hinode/XRT using EBTEL and found that they required multiple heating events, but could not distinguish between multiple heating events on a single strand, or multiple strands each experiencing a single heating event. We present here a similar study, but with EUV data of Active Region 11520 from the High Resolution Coronal Imager (Hi-C) sounding rocket. Hi- C provides an order of magnitude improvement to the spatial resolution of XRT, and a cooler temperature sensitivity, which combine to provide significant improvements to our ability to detect and model microflare activity around active regions. We have found that at the spatial resolution of Hi-C (approximately 0.3 arcseconds), the events occur much more frequently than expected (57 events detected, only 1 or 2 expected), and are most likely made from strands of order 100 km wide, each of which is impulsively heated with multiple heating events. These findings tend to support bursty reconnection as the cause of the energy release responsible for the brightenings.

Authors: Adam R. Kobelski, David E. McKenzie
Projects: Hi-C

Publication Status: ApJ (Accepted)
Last Modified: 2014-08-27 12:58
Go to main E-Print page  Edit Entry  Download Preprint  Submitter's Homepage Delete Entry 

Modeling Active Region Transient Brightenings Observed with X-Ray Telescope as Multi-stranded Loops  

Adam Kobelski   Submitted: 2014-08-22 18:16

Strong evidence exists that coronal loops as observed in extreme ultraviolet and soft X-rays may not be monolithic isotropic structures, but can often be more accurately modeled as bundles of independent strands. Modeling the observed active region transient brightenings (ARTBs) within this framework allows for the exploration of the energetic ramifications and characteristics of these stratified structures. Here we present a simple method of detecting and modeling ARTBs observed with the Hinode X-Ray Telescope (XRT) as groups of zero-dimensional strands, which allows us to probe parameter space to better understand the spatial and temporal dependence of strand heating in impulsively heated loops. This partially automated method can be used to analyze a large number of observations to gain a statistical insight into the parameters of coronal structures, including the number of heating events required in a given model to fit the observations. In this article, we present the methodology and demonstrate its use in detecting and modeling ARTBs in a sample data set from Hinode/XRT. These initial results show that, in general, multiple heating events are necessary to reproduce observed ARTBs, but the spatial dependence of these heating events cannot yet be established.

Authors: Adam R. Kobelski, David E. McKenzie, Martin Donachie
Projects: Hinode/XRT

Publication Status: ApJ (Accepted)
Last Modified: 2014-08-27 12:58
Go to main E-Print page  Edit Entry  Download Preprint  Submitter's Homepage Delete Entry 

Calibrating Data from the Hinode/X-Ray Telescope and Associated Uncertainties  

Adam Kobelski   Submitted: 2013-12-18 02:05

The X-Ray Telescope (XRT) onboard the Hinode satellite, launched 23 September 2006 by the Japanese Aerospace Exploration Agency (JAXA) is a joint mission between Japan, the United States, and the United Kingdom to study the solar corona. In particular XRT was designed to study solar plasmas with temperatures between 1 and 10 MK with ≈1″ pixels (≈2″ resolution). Prior to analysis, the data product from this instrument must be properly calibrated and data values quantified in order to assess accurately the information contained within. We present here the standard methods of calibration for these data. The calibration is performed on an empirical basis which uses the least complicated correction that accurately describes the data while suppressing spurious features. By analyzing the uncertainties remaining in the data after calibration, we conclude that the procedure is successful, as the remaining uncertainty after calibration is dominated by photon noise. This calibration software is available in the Solar Soft software library.

Authors: Adam R. Kobelski, Steven H. Saar, Mark A. Weber, David E. McKenzie, Katharine K. Reeves
Projects: Hinode/XRT

Publication Status: 26 pages, 16 figures, Accepted for publication in Solar Physics
Last Modified: 2013-12-18 09:50
Go to main E-Print page  Edit Entry  Download Preprint  Submitter's Homepage Delete Entry 


Key
Go to main E-Print pageGo to main E-Print page.
Download PreprintDownload Preprint.
Submitter's HomepageSubmitters Homepage.
Edit EntryEdit Entry.
Delete AbstractDelete abstract.

Abstracts by Author
Forward Modeling Transient Brightenings and Microflares around an Active Region Observed with Hi-C
Modeling Active Region Transient Brightenings Observed with X-Ray Telescope as Multi-stranded Loops
Calibrating Data from the Hinode/X-Ray Telescope and Associated Uncertainties

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