Fifth Illkirch Survey of
Joachim Köppen Strasbourg Feb. 2012
This applet shows the results of the fifth survey at the radio line of atomic
hydrogen at 21 cm wavelength, done with the
ESA-Haystack radio telescope at the International Space University
in Illkirch, between June 2011 and February 2012, with some pauses due to
mechanical problems. At times we also suffered from electronic interference,
which was manually removed from the data, but the presence of which may still be
discerned in some data sets.
The system temperature was about 300 K or below.
The data are given for each galactic longitude (from 0° to 248° in steps
of 2°) as scans in galactic latitude from -30° to +30° (in steps of 2°), with a
coverage in radial velocity from -150 to +150 km/s.
- Enter the value of the longitude in the textfield and hit the Enter key.
There are a few gaps in the data; when requesting an unavailable
longitude, an appropriate message will appear ...
- Read File reads the file for the longitude entered
- File Info shows the header of the FITS file, giving some internal information
- Vr-b map is the default way of showing the data as a false colour
map. The colour scheme can be selected by the Choice
below. The button autorange toggles between
an automatic setting of the colour band between minimum
and maximum values in the data (displayed), and a manual
entry of these values (in the corresponding TextFields).
- Vert.Profile makes a plot of the total intensity as a function of latitude.
Here one can also overlay curves of a gaussian fit of the central
part, and of the data smoothed with the specifed FWHM
- Plot shows the spectrum at a specific latitude. The adjoining buttons
allow to change this latitude, which is indicated by a white line
in the Vr-b map.
- Output writes the spectrum of the current latitude in the form of a
plain text table which may be copied and pasted into a text editor
for further storage and analysis.
- freq.smooth ... allows to smooth the spectra in radial velocity. When
active (green button), any newly-read in data will be smoothed
with the value in the TextField (in km/s). When this option is
modified, press Read File button to apply it to the
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last update: Feb. 2012 J.Köppen