Multi-Instrument Solar Flare Observations I: Solar Flare Finder
| Nugget | |
|---|---|
| Number: | 297 |
| 1st Author: | Ryan Milligan |
| 2nd Author: | Kim Tolbert |
| Published: | 3 April 2017 |
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Introduction
The solar physics community is fortunate to have access to a great deal of data from many solar observatories, both in space and on the ground. These instruments provide imaging, photometric, and spectroscopic data over a range of wavelengths, from radio waves through the optical and EUV to X-rays and gamma-rays. Often the greatest advances in our understanding of solar flares come through various combinations of these datasets. However, unless one is an instrument planner or someone who monitors daily solar activity, it is difficult to keep track of which flares have been observed by which instruments. The RHESSI-funded Max Millennium Program for Solar Flare Research (Ref. 1) and others have aimed to optimise the scientific return on this data by coordinating ground and space based instrumentation to observe a flaring active region simultaneously. Indeed, shortly after RHESSI's first light, joint multi-wavelength observations of solar flares were strongly encouraged. However, this can be difficult due to factors such as coordinating across multiple time zones, planning schedules being uploaded days in advance, ground-based seeing conditions, competing scientific priorities, and so on. To this end an IDL widget has been developed to retrospectively search metadata from the archival databases of RHESSI, SDO/EVE (MEGS-A and MEGS-B), Hinode (EIS, SOT and XRT) and IRIS for flaring events jointly observed by multiple instruments. Simply type IDL> solar_flare_finder at the command line to bring up the window shown in Figure 1.
From here, a user can search by:
- GOES Class (B, C, M, X)
- Maximum Energy Detected by RHESSI
- Whether RHESSI observed some (>0%) or most (>90%) of the impulsive phase
- Flare location (disc vs. limb) based on location derived from AIA images
- Whether it was observed by other instruments such as EVE MEGS-A or MEGS-B, the Hinode/EIS, SOT or XRT, or IRIS
Clicking on a flare in the list that is returned will bring up a plot of the metadata of the RHESSI and GOES lightcurves with longer wavelength observations overlaid. An EUV or X-ray image is also shown with reduced FOVs overplotted. This plot, and a .sav file containing the metadata, is also downloadable.
Search Method
The Solar Flare Finder widget searches a pre-generated lookup table to instantly return a list of flares corresponding to the user's criteria. The construction of the table begins with the SSW Latest Events list, which is accessible via the HEK knowledgebase. This list is based on the familiar NOAA GOES event list except it contains the location information of each flare based on SDO/AIA 131A difference images. This is required to compare with limited-FOV instruments. Details on how the databases were cross-referenced are laid out in Ref. [2], or by clicking on the "Help" button in the widget.
Biographical Note
Ryan Milligan is currently an Ernest Rutherford Fellow at the University of Glasgow.