A catalogue of 108 extended planetary nebulae observed by GALEX
  We present the ultraviolet (UV) imaging observation of planetary nebulae
(PNe) using archival data of Galaxy Evolution Explorer (GALEX). We found 358
PNe detected by GALEX in near-UV (NUV). We have compiled a catalogue of 108
extended PNe with sizes greater than 8 00 and provided the angular diameters
for all the 108 extended PNe in NUV and 28 in FUV from the GALEX images
considering 3{\sigma} surface brightness level above the background. Of the 108
PNe, 74 are elliptical, 24 are circular and 10 are bipolar in NUV with most
being larger in the UV than in the radio, H{\alpha} or optical. We derived
luminosities for 33 PNe in FUV (L FUV ) and 89 PNe in NUV (L NUV ) and found
that most of the sources are very bright in UV. The FUV emission of the GALEX
band includes contribution from prominent emission lines N IV] (1487 {\AA}),
CIV (1550 {\AA}), and O III] (1661 {\AA}) whereas the NUV emission includes C
III] (1907 {\AA}) and C II (2325 {\AA}) for PNe of all excitation classes. The
other emission lines seen in low excitation PNe are O IV] (1403 {\AA}) and N
III(1892 {\AA}) in FUV, and O II (2470 {\AA}) and Mg II (2830 {\AA}) in NUV.
Similarly the emission lines O V (1371 {\AA}) and He II (1666 {\AA}) strongly
contribute in FUV for high and medium excitation PNe but not for low excitation
PNe. A mixture of other emission lines seen in all excitation PNe. We have also
provided images of 34 PNe in NUV and 9 PNe in FUV.
