RHESSI data (and software) are of course freely available to all, but
to view the data directly often requires some training or study.
Accordingly one needs a simple overview, and
Browser - a Web interface - fills this need.
This science nugget will not be providing
knowledge on some scientific topic, but rather on how to use Browser
to its maximum potential in the pursuit of science. As many of you
already know, Browser is a very useful tool to browse through many
different types of RHESSI-related data plots simultaneously. However,
I suspect that many of you may not realize some of its not-so-obvious
capabilities. If so, read on!
First, if you are rather unfamiliar with Browser, just
play with it!
Perhaps pick a time when you know something interesting happened,
and start clicking around on various icons and links. Feel free
The most useful icons or links may be the question-mark
icon at the top and the "Help" link at the bottom. Both will open
the help page, which may answer any basic questions you may have.
next most useful icons are the magnifying-glass icons that are
littered across the page. Clicking on such an icon will reveal
advanced options that may turn out to be indispensable for your
method of using Browser.
Finally, one should not forget the red-arrow
icons, which indicate a particular time on all plots that have a
time axis. Combined with the ability to click on plots to select
a specific time, one can click on a feature of interest on one plot,
and then the red arrow will identify the same time on all the other
I will now present two case studies for how one might
Case Study 1: X4.8 Solar Flare on 2002 July 23
Figure 1. Clicking on the picture below will open a "larger"
version directly in browser. The text in this section describes each numbered panel.
|I will first discuss the typical use of Browser to
look at solar flares, and I have chosen the much-studied X4.8 solar
flare on 2002 July 23.
Click on the image on the left to open the actual Browser
page in a new window.
Now to explain its elements...
Note that there are quite a few plots open, although these are
only a fraction of the possible number.
Unsurprisingly, the more
plots that are open, the longer the page takes to load completely,
so I would suggest a smaller set for casual browsing, and then
opening other plots when necessary. However, if you ordinarily view
only one plot at a time in Browser, I would strongly encourage you
to try browsing with multiple plots open.
The first plot  shows
the GOES lightcurves with the RHESSI times for eclipse and radiation-belt
passages superposed (no data and bad data, respectively).
For many flares, one can use these plots
to determine whether a given flare has observed.
This plot is also useful to jump between multiple flares on a single day (see
the red-arrow icon discussion above).
plots  show the corrected and uncorrected rates for the orbit.
"Quicklook" is rich collection of reduced secondary databases -
lightcurves, images, and spectra. A brief digression: when you see interesting behavior on the
corrected-rates plot, be sure to check the uncorrected-rates plots to
make sure that the behavior was not simply a correction artifact.
For example, the attenuation by the shutters was corrected for in
this flare, but note that the 7000-20000 keV band has picked up a
small spike at 0041 UT that is clearly a correction artifact (there
is nothing to correct for at such high energies).
quicklook plot  shows a sampling of the data from the particle
counters on RHESSI (on board mainly to track
Earth's radiation belts).
The top and bottom halves show lightcurves for
the detectors that usually respond to electrons and protons,
respectively. In this particular example, there is a short burst
of activity after 0100 UT. By using the red-arrow icons to identify
the same time on the quicklook lightcurve plots, we see the particle
activity did in fact produce an effect visible in the RHESSI
lightcurves, although fortunately well after virtually all the
interesting flare emission.
The next three plots  are various
types of quicklook images for this flare, and the following plot 
GOES, RHESSI, and
WIND particle data, and also includes the RHESSI data in
The final three plots  above are examples of monitor-rates
plots. The first plot shows the "slow valid" (i.e. good) counts in
each of the nine front segments. Of course, the quicklook lightcurve
plots are usually much more useful, but this plot has its uses.
For example, the artifact in detector 8 due to interference from
the aft antenna can be clearly seen (e.g. 1650 UT). The following
two plots show the livetimes in the front segments and the rear
segments. Note that since flare photons tend to stop in the front
segments before reaching the rear segments, the rear segments have
substantially more livetime than the front segments. However, this
relationship does not hold for non-solar photons such as those from
nearby particle precipitation events. There are many more monitor-rate
plots, but they are probably too technical for most users.
Case Study 2: Magnetar Burst on 2004 December 27
Figure 2. Clicking on the picture below will open a "larger"
version directly in browser. The text in this section describes each numbered panel.
Now let us take a look at an event that was not a
solar flare, specifically the
magnetar burst on 2004 December 27.
(Even though RHESSI flagged this event a solar flare, it is most
definitely not one.)
Looking at the quicklook plots , one can see an egregious correction
artifact where many of the lightcurves shift to a new baseline after
the magnetar burst. Again, one should always remember to check the
uncorrected-rates plots when seeing strange behavior.
two quicklook plots  show the count lightcurves for the nine front
segments and nine rear segments, respectively. One can use these
plots in much the same way as the corresponding monitor-rates plots,
and, in addition, flares are marked by lines on these plots.
The next plot 
is an attempt to display a quicklook image plot for this event.
Since this non-solar event cannot be imaged, an error message appears instead.
Finally, there is the GOES/RHESSI/WIND plot . Note that the GOES
data shows that the burst went virtually unrecorded in the low-energy
channel. It would have been difficult to pick out this event on
the usual GOES-with-RHESSI-times plots. Also note the appearance
of the burst in the spectrogram, and compare it against the
totally unrelated particle
precipitation event that occurred an hour later at 2340 UT.
first advanced feature that you may not have been aware of is that
Browser automatically synchronizes links to corresponding data on
other websites at the same time as currently selected in Browser.
For example, if you have the first case study open, you can click on the
"Active Region Monitor"
link on that page to bring up SOHO data
for the 2002 July 23 flare.
advanced feature is the ability to create links to a specific time
with particular plots open (like the two case studies above). Once
you have arranged Browser in the way you want, you can click the
"Direct URL" button (or right-click and save the link's location)
to access the custom shortcut. One can then bookmark the page, or
perhaps send it to a colleague for consultation. Incidentally, if
one clicks the "Reset Date" button immediately before using the
"Direct URL" button, then the time information is erased, and
the direct URL stores only the current view layout (e.g. my
Finally, there is a major timesaver in the form of text
fields for the flare number or time (click the magnifying-glass
icon next to the year-selection box). Although these fields are
somewhat useful as output fields, their real power comes from using
them as input fields. One can enter a specific flare number or a
specific time (in most
Solarsoft-compatible formats), and Browser
will jump to the corresponding time. This feature works great when
analyzing a list of events. Note that there is an eraser button
provided to aid copy-and-pasting on systems where selecting
automatically overwrites the contents of the clipboard.
I hope this discussion introduced you to Browser and some new facets that
you had not been aware of.
with comments and suggestions
on Browser, and if I happen across any free time, I will see what
I can do. But, as is, Browser has helped my own research immensely,
and I hope that you will be able to say the same.
Albert Shih is a graduate student at UC Berkeley, working on a PhD
thesis analyzing solar gamma-ray flares.