add credits

speccy.html

@@ -376,22 +376,23 @@
         <li> Left-clicking the button displays the coordinates of the pointer position at the time of the click in the bottom right hand of the spectrum plot. </li>
         <li> Plots of the current spectral view can be saved directly as .png files using the 'Save current view as as .png' button. </li>
         <li> Please send comments, complaints and suggestions to <a href="mailto:dwelly@mpe.mpg.de">dwelly@mpe.mpg.de</a></li>
+    </ul>
 </p>
 
 <h4>Speccy File format:</h4> 
 <p>
     Speccy expects plain ASCII text files as input.<br>
-    Header entries are prefixed by a hash and contain "key = value" pairs. e.g. '# PLATE = 1234'<br>
+    Header entries are prefixed by a hash+space and contain "key = value" pairs. e.g. <samp>'# PLATE = 1234'</samp><br>
     The main body of the speccy file should contain five comma-separated columns
     (with all fluxes in units 10<sup>-17</sup> erg cm<sup>-2</sup> s<sup>-1</sup> &Aring;<sup>-1</sup>):
 </p>
 <blockquote><samp>Observed Vacuum Wavelength (&Aring;), Flux, FluxError, SkyFlux, ModelFlux</samp></blockquote>
 <p>
-    Template files must contain two comma-separated columns:
+    Template files must contain (at least) two comma-separated columns:
 </p>
 <blockquote><samp>Rest-frame Vacuum Wavelength (&Aring;), ModelFlux (F<sub>&lambda;</sub>)</samp></blockquote>
 
-<p> Note. Therefore a normal Speccy spectrum file can be used as a template</p>
+<p> Note. Only the first two columns of template files are noticed, and so a regular Speccy spectrum file can be used as a template</p>
 <hr>
 
 
@@ -469,7 +470,12 @@ These are the lines that are plotted over the spectra.
     </tr>
 </table>
 
-<div style='text-align:left'>[<a href='/impressum'>Imprint</a> <a href='/data-protection'>Privacy Policy</a>]</div>
+<hr>
+<div style='text-align:left'>
+    <h4>Credits</h4>
+    This tool makes use of the <a href="legacysurvey.org">legacysurvey.org</a> <a href="https://www.legacysurvey.org/viewer">viewer</a>, and the <a href="https://alasky.u-strasbg.fr/hips-image-services/hips2fits">hips2fits</a> service provided by CDS.</div>
+<hr>
+<div style='text-align:right'>[<a href='/impressum'>Imprint</a> <a href='/data-protection'>Privacy Policy</a>]</div>
 
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