Correlation of He II lyman alpha with He I 10830 Å, and with chromospheric and EUV coronal emission

Abstract

This paper describes the results of comparing SERTS-3 images obtained in the transition region line of Heii 304 Å with chromospheric Hei 10830 Å absorption, with strong coronal lines of Mgix 368 Å, Fexv 284 Å and 417 Å, and Fexvi 335 Å and 31 Å, with Hα, with Caii 8542 Å, and with magnetograms in Fei 8688Hα. All of the images are illustrated, and the image reconstruction techniques used are described and evaluated. The high correlation of the Heii 304 Å and Hei 10830 Å images, originally found by Harvey and Sheeley (1977), is confirmed and is put on a quantitative basis. We find that the supergranulation network has greater contrast, and that filaments appear darker, in 10830 Å than in 304 Å. In active regions, the 304 Å line follows more closely the behavior of Hα and Caii 8542 Å than the 10830 Å line.