1. Orion-KL EVLA spectrum Karl Menten, Dec. 28, 2010 Received spectra from R. Perley on Dec. 23 and 28, 2010 Frequency range 23654.50–26654.37 MHz Subtracted 2.2586 MHz to frequencies so that NH 3 lines are centered at their rest frequencies. Scale was fixed by assuming an LSR velocity of ≈ +8 km/s (for the (J,K) = (1,1), (2,2),and (3,3) lines (Barrett et al. 1977, ApJ 211, L39) (Barrett et al. 1977, ApJ 211, L39) Comment: Data appear to be of very high quality. There are a few single channel spikes of intensity a few sigma increased noise level at frequencies higher than 24.5 GHz

2. Line content of spectrum Detect total of 31 “strong”(ish) lines 29 previously detected in ISM, listed on Lovas’ website: http://physics.nist.gov/PhysRefData/Micro/Html/contents.html Dominated by lines from ammonia (NH 3 ) and methanol (CH 3 OH) Two E/A doublets of methyl formate CH 3 CHO OCS 2-1 three SO 2 lines with Energies of 35, 42, and 253 K above the ground state ~1 unidentified line above 5 cal. units There certainly are (unidentified, but possiby identifiable) weaker lines in the spectrum

3. Ammonia (NH 3 ) 8 lowest meta-stable inversion transitions (J,K) = (1,1), (2,2), (3,3), up to (8,8) non-meta-stable (9,8) and (10,9) lines (6,6) line from 15 NH 3 isotopologue, [ 14 N/ 15 N]≈250 (weak) 4(1,4)-4(0,4) line from singly deuterated ammonia, NH 2 D

4. Methanol (CH 3 OH) ten strong maser lines from J k=2 -J k=1 E-type series (J = 2 –11) between 24.9 and 26.3 GHz non-meta-stable (9,8) and (10,9) lines (6,6) line from 15 NH 3 isotopologue, [ 14 N/ 15 N]≈250 (weak) 4(1,4)-4(0,4) line from singly deuterated ammonia, NH 2 D

5. Line rest frequencies 23657.471 ( 5) NH3 9(8)-9(8) 23693.9051( 1) NH3 1(1)-1(1) F,F1=3/2,1-5/2,2 23694.4700( 1) NH3 1(1)-1(1) F,F1=1/2,1-3/2,1 23694.5060( 1) NH3 1(1)-1(1) F,F1=5/2,2-5/2,2 23695.0672( 1) NH3 1(1)-1(1) F,F1=3/2,2-3/2,1 23696.0297( 2) NH3 1(1)-1(1) F,F1=1/2,0-1/2,1 23720.575 ( 5) NH3 2(2)-2(2) F1=1-2 23721.336 ( 5) NH3 2(2)-2(2) F1=3-2 23722.6336( 1) NH3 2(2)-2(2) F1=3-3 23723.929 ( 5) NH3 2(2)-2(2) F1=2-3 23724.691 ( 5) NH3 2(2)-2(2) F1=2-1 23867.805 ( 5) NH3 3(3)-3(3) F1=2-3 23868.450 ( 5) NH3 3(3)-3(3) F1=4-3 23870.1296( 1) NH3 3(3)-3(3) F1=4-4 23871.807 ( 5) NH3 3(3)-3(3) F1=3-4 23872.453 ( 5) NH3 3(3)-3(3) F1=3-2 23922.313 ( 2) 15NH3 6(6)-6(6) 24039.641 ( 2) SO2 21(5,17)-22(4,18) 24083.455 ( 2) SO2 8(2,6)-9(1,9) 24139.4169( 1) NH3 4(4)-4(4) 24205.287 ( 5) NH3 10(9)-10(9) 24296.491*( 8) CH3OCHO 2(0,2)-1(0,1) E 24298.481*( 8) CH3OCHO 2(0,2)-1(0,1) A 24325.927 ( 1) OCS 2-1 24532.9887( 1) NH3 5(5)-5(5) Meta-stable NH3 lines have 5 main groups of hyperfine structure components which are blended in Orion-KL spectrum

6. Line rest frequencies (cont’d) 24928.715*(14) CH3OH 3(2,1)-3(1,2) E 24933.468 ( 2) CH3OH 4(2,2)-4(1,3) E 24934.382 ( 5) CH3OH 2(2,0)-2(1,1) E 24959.079 ( 2) CH3OH 5(2,3)-5(1,4) E 25018.123 ( 2) CH3OH 6(2,4)-6(1,5) E 25023.792 (10) NH2D 4(1,4)-4(0,4) 25056.025 ( 5) NH3 6(6)-6(6) 25124.872 ( 2) CH3OH 7(2,5)-7(1,6) E 25294.417 ( 2) CH3OH 8(2,6)-8(1,7) E 25392.776 (20) SO2 8(1,7)-7(2,6) (first detection) 25541.398 ( 2) CH3OH 9(2,7)-9(1,8) E 25715.182 ( 5) NH3 7(7)-7(7) 25878.266 ( 2) CH3OH 10(2,8)-10(1,9) E 26044.796*( 8) CH3OCHO 2(1,1)-1(1,0) E 26048.534*( 8) CH3OCHO 2(1,1)-1(1,0) A 26120.584 (10) CH3OH 10(1,9)-11(2,10)A - 26313.124 (50) CH3OH 11( 2, 9)-11 (1,10) E (first detection) 26518.981 (10) NH3 8(8)-8(8)

10. SO 2 J K-,K+ = 8 1,7 –7 2,6 50 km/s