OH in the solar spectrum

Abstract

eH lines in the solar spectrum have been ident ifi ed b.I' direct co m pari so n of meas ured laboratory and solar wavelengt hs an d intensiLi es. The comparison of individu al roLational lin es are included in a seri es of tables arranged according to electroni c and yibraLional transitions. A deta iled investigation of the presence of CH lille in the solar spectrum h as been carried out rccc ntl.,-as part of the preparation of a current edition of solar sp ectrum data to replace the 1928 compendium [1].1 Along with th e study of atomic lines, a parallel survey of molecul es in t h e sun is requir ed for any complete r evision of th e "Solar pectrum." A preliminary resume of th e number of CR , OH, and CN lines in th e solar sp ectrum wa recently publish ed [2]. iIlany lines of CH are familial' featur es in the solar spec tnlm. I n his original table, R owland [3] attributed some of t hese line to "C," and numerou s CR lines wer e includ ed in the 192 edition [1]. Several authors have canied th e work fUl'ther. For example, I-hmaerts [4] and Richardson [5] h ave each publish ed a li st of solar lines which m ay b e ascribed to CH. The present res ulLs a re based on a study of th e rotation al structure of indiv idu al band , togeth er with r elat ive labor atory intensities m easu red along th e diffe rent branchcs. It reveal more CH lines in the sun than h ave b ecn recogn ized h ereto fore. A ummary of th e co unts is. inclucled in table 1. In this tab' le the counts are h andled d ifferen tly th all the:,,-were previoLlsly, in th at the co unts r efer to indi\' idual laboratory lin es; wherea in th e earlier paper [2] th ey referred to solar lines. OOll sequenLly, if two OH lines cont rib ute to one solar line, each CH line is co unted h ere as a blend. Exception h as been made in th e casc of table 10, where the laboratory line ar e so closely blended Lhat for som e groups they are not counted as separate lines. The total numb er of laboratory lines given for this band is 119 ± to denote th at th e coun t is somewhat arbitrary. If only th e leading lines of a b and are present in th e sun, the coun ts refer only to the stron ger lines of the band, as for example in table 5, where only 31 lines out of 198 enter into th e coun t. The individual rotational bands a re describ ed in tables 2 to 11. D ata on th e laborator y a nalyses ar e given on th e left h and side of each Lable, and th e olar data are en tered on Lh e righ t. In table 6 only labora tory data are given, sinc e thi s band is not observed in the sun. Un der th e general heading, " Laboratory," th e respective ro tational quanLum numb ers of Lh e P , Q, and R branch es are entered as indicated by t h e respective h eadings. L ines of weak satellite bran ch es are indicated by th e symbol t, and a summary of I Figures in brackets indicate the literature references at the end of this paper. 19 th e satelli te lines is included in footnote to the tabl es. These ent ries are followed by an inLensiLy col umn. In tensit ies have been d etermined from m eaSLlre-m ents of the emission from the reaction zone of an acetylene-oxygen :fl ame. A question mark (?) after the intensity number indicaLes a questionable jn-tensit:"T m easurem ent cau ed by som e overlappin g from a strong neighboring line. (CH) indicfttes a weak line m asked b:"T a stronger OH line, whereas "1\11 " indicate rna k ing by som e other emission in the laboratory som ce. In table 11 (OH) is entercd as masking Cl-I in ome cases. Blank spaces in th e intensity column resul t from lines too weak [0 be observed under th e conditions used to obtain intensities.