COVER INFORMATION Station: SVETLOE (Code Sv ) Experiment: A definite answer to the nature of the water gigamaser in TXS2226-184 Exp. Code: ET045B Schedule Version: 2.00 Processed by SCHED version: 11.60 Release 11.6; April 2020 PI: A. Tarchi Address: INAF - Osservatorio Astronomico di Cagliari Via della Scienza 5 I-09047 Selargius (Cagliari) Italy Phone: +39 07071180235 EMAIL: andrea.tarchi@inaf.it Fax: Phone during observation: +39 07071180235 Observing mode: Observations of TXS2226-184 at 5 GHz (2048 Mb/s) Notes: phase-cal OFF EVN+MERLIN Schedule for SVETLOE (Code Sv ) Page 2 A definite answer to the nature of the water gigamaser in TXS2226-184 UP: D => Below limits; H => Below horizon mask; W => still slewing at end; blank => Up. Early: Seconds between end of slew and start. Dwell: On source seconds. Disk: GBytes recorded to this point. TPStart: Recording start time. Frequencies are LO sum (band edge). SYNC: Time correlator is expected to sync up. ---------------------------------------------------------------------------------------- Start UT Source Start / Stop Early Disk TPStart Stop UT LST EL AZ HA UP ParA Dwell GBytes SYNC ---------------------------------------------------------------------------------------- --- Sun 7 Mar 2021 Day 66 --- Next scan frequencies: 4830.49 4830.49 4830.49 4830.49 4894.49 4894.49 4894.49 4894.49 4958.49 4958.49 4958.49 4958.49 5022.49 5022.49 5022.49 5022.49 Next BBC frequencies: 330.49 330.49 330.49 330.49 394.49 394.49 394.49 394.49 458.49 458.49 458.49 458.49 522.49 522.49 522.49 522.49 Next scan bandwidths: 32.00 32.00 32.00 32.00 32.00 32.00 32.00 32.00 32.00 32.00 32.00 32.00 32.00 32.00 32.00 32.00 07 30 00 3C345 20 30 06 49.9 625.2 3.8 39.6 0 0 07 30 00 07 38 00 --- 20 38 08 48.9 627.0 3.9 39.7 480 123 07 30 01 07 54 30 J2232-1659 20 54 40 10.1 516.0 -1.6 -12.1 851 123 07 54 30 07 56 30 =2229-172 20 56 41 10.2 516.5 -1.6 -11.8 120 154 07 54 31 08 00 00 J2232-1659 21 00 11 10.3 517.3 -1.6 -11.4 203 154 08 00 00 08 02 00 =2229-172 21 02 11 10.4 517.8 -1.5 -11.2 120 185 08 00 01 08 05 00 J2232-1659 21 05 12 10.6 518.5 -1.5 -10.8 173 185 08 05 00 08 07 00 =2229-172 21 07 12 10.7 519.0 -1.4 -10.6 120 215 08 05 01 08 10 30 J2232-1659 21 10 43 10.8 519.9 -1.4 -10.2 203 215 08 10 30 08 12 30 =2229-172 21 12 43 10.9 520.3 -1.3 -10.0 120 246 08 10 31 08 15 30 J2232-1659 21 15 44 11.0 521.1 -1.3 -9.6 173 246 08 15 30 08 17 30 =2229-172 21 17 44 11.1 521.6 -1.3 -9.4 120 277 08 15 31 08 17 30 TXS 21 17 44 10.0 522.5 -1.2 -9.0 -14 277 No stop 08 20 30 --- 21 20 44 10.1 523.2 -1.2 -8.6 166 323 08 17 31 08 21 00 J2232-1659 21 21 15 11.2 522.4 -1.2 -8.9 16 323 08 21 00 08 23 00 =2229-172 21 23 15 11.3 522.9 -1.2 -8.7 120 354 08 21 01 08 23 00 TXS 21 23 15 10.2 523.8 -1.1 -8.3 -14 354 No stop 08 26 00 --- 21 26 15 10.3 524.5 -1.1 -7.9 166 400 08 23 01 08 26 00 J2232-1659 21 26 15 11.4 523.6 -1.1 -8.3 -14 400 No stop 08 28 00 =2229-172 21 28 16 11.5 524.1 -1.1 -8.1 106 431 08 26 01 08 28 00 TXS 21 28 16 10.4 525.0 -1.0 -7.7 -14 431 No stop 08 31 00 --- 21 31 16 10.5 525.7 -1.0 -7.3 166 477 08 28 01 08 31 30 J2232-1659 21 31 46 11.6 524.9 -1.0 -7.7 16 477 08 31 30 08 33 30 =2229-172 21 33 47 11.7 525.4 -1.0 -7.4 120 508 08 31 31 08 33 30 TXS 21 33 47 10.6 526.3 -0.9 -7.0 -14 508 No stop 08 36 30 --- 21 36 47 10.7 527.1 -0.9 -6.7 166 554 08 33 31 Schedule for SVETLOE (Code Sv ) Page 3 A definite answer to the nature of the water gigamaser in TXS2226-184 UP: D => Below limits; H => Below horizon mask; W => still slewing at end; blank => Up. Early: Seconds between end of slew and start. Dwell: On source seconds. Disk: GBytes recorded to this point. TPStart: Recording start time. Frequencies are LO sum (band edge). SYNC: Time correlator is expected to sync up. ---------------------------------------------------------------------------------------- Start UT Source Start / Stop Early Disk TPStart Stop UT LST EL AZ HA UP ParA Dwell GBytes SYNC ---------------------------------------------------------------------------------------- --- Sun 7 Mar 2021 Day 66 --- 08 36 30 J2232-1659 21 36 47 11.7 526.2 -0.9 -7.1 -14 554 No stop 08 38 30 =2229-172 21 38 47 11.8 526.6 -0.9 -6.8 106 585 08 36 31 08 38 30 TXS 21 38 47 10.7 527.5 -0.9 -6.4 -14 585 No stop 08 41 30 --- 21 41 48 10.8 528.3 -0.8 -6.0 166 631 08 38 31 08 42 00 J2232-1659 21 42 18 11.9 527.5 -0.9 -6.4 16 631 08 42 00 08 44 00 =2229-172 21 44 18 12.0 528.0 -0.8 -6.1 120 662 08 42 01 08 44 00 TXS 21 44 18 10.8 528.9 -0.8 -5.7 -14 662 No stop 08 47 00 --- 21 47 19 10.9 529.6 -0.7 -5.4 166 708 08 44 01 08 47 00 J2232-1659 21 47 19 12.0 528.7 -0.8 -5.8 -14 708 No stop 08 49 00 =2229-172 21 49 19 12.1 529.2 -0.7 -5.5 106 738 08 47 01 08 49 00 TXS 21 49 19 11.0 530.1 -0.7 -5.1 -14 738 No stop 08 52 00 --- 21 52 20 11.0 530.8 -0.6 -4.7 166 785 08 49 01 08 52 30 J2232-1659 21 52 50 12.2 530.1 -0.7 -5.1 15 785 08 52 30 08 54 30 =2229-172 21 54 50 12.2 530.5 -0.6 -4.8 120 815 08 52 31 08 54 30 TXS 21 54 50 11.1 531.4 -0.6 -4.4 -15 815 No stop 08 57 30 --- 21 57 51 11.1 532.1 -0.5 -4.1 165 862 08 54 31 08 57 30 J2232-1659 21 57 51 12.3 531.3 -0.6 -4.5 -15 862 No stop 08 59 30 =2229-172 21 59 51 12.3 531.8 -0.6 -4.2 105 892 08 57 31 08 59 30 TXS 21 59 51 11.2 532.6 -0.5 -3.8 -15 892 No stop 09 02 30 --- 22 02 51 11.2 533.3 -0.5 -3.4 165 938 08 59 31 09 03 00 J2232-1659 22 03 21 12.4 532.6 -0.5 -3.8 15 938 09 03 00 09 05 00 =2229-172 22 05 22 12.4 533.1 -0.5 -3.5 120 969 09 03 01 09 05 00 TXS 22 05 22 11.2 534.0 -0.4 -3.1 -15 969 No stop 09 08 00 --- 22 08 22 11.3 534.7 -0.4 -2.7 165 1015 09 05 01 09 08 00 J2232-1659 22 08 22 12.4 533.9 -0.4 -3.2 -15 1015 No stop 09 10 00 =2229-172 22 10 23 12.4 534.3 -0.4 -2.9 105 1046 09 08 01 09 10 00 TXS 22 10 23 11.3 535.2 -0.3 -2.5 -15 1046 No stop 09 13 00 --- 22 13 23 11.3 535.9 -0.3 -2.1 165 1092 09 10 01 09 13 30 J2232-1659 22 13 53 12.5 535.2 -0.3 -2.5 15 1092 09 13 30 09 15 30 =2229-172 22 15 54 12.5 535.7 -0.3 -2.2 120 1123 09 13 31 Schedule for SVETLOE (Code Sv ) Page 4 A definite answer to the nature of the water gigamaser in TXS2226-184 UP: D => Below limits; H => Below horizon mask; W => still slewing at end; blank => Up. Early: Seconds between end of slew and start. Dwell: On source seconds. Disk: GBytes recorded to this point. TPStart: Recording start time. Frequencies are LO sum (band edge). SYNC: Time correlator is expected to sync up. ---------------------------------------------------------------------------------------- Start UT Source Start / Stop Early Disk TPStart Stop UT LST EL AZ HA UP ParA Dwell GBytes SYNC ---------------------------------------------------------------------------------------- --- Sun 7 Mar 2021 Day 66 --- 09 15 30 TXS 22 15 54 11.3 536.5 -0.2 -1.8 -15 1123 No stop 09 18 30 --- 22 18 54 11.4 537.2 -0.2 -1.4 165 1169 09 15 31 09 18 30 J2232-1659 22 18 54 12.5 536.4 -0.2 -1.8 -15 1169 No stop 09 20 30 =2229-172 22 20 54 12.5 536.9 -0.2 -1.6 105 1200 09 18 31 09 20 30 TXS 22 20 54 11.4 537.7 -0.2 -1.2 -15 1200 No stop 09 23 30 --- 22 23 55 11.4 538.4 -0.1 -0.8 165 1246 09 20 31 09 24 00 J2232-1659 22 24 25 12.6 537.8 -0.2 -1.1 15 1246 09 24 00 09 26 00 =2229-172 22 26 25 12.6 538.3 -0.1 -0.9 120 1277 09 24 01 09 26 00 TXS 22 26 25 11.4 539.1 -0.1 -0.5 -15 1277 No stop 09 29 00 --- 22 29 26 11.4 539.8 -0.0 -0.1 165 1323 09 26 01 09 29 00 J2232-1659 22 29 26 12.6 539.0 -0.1 -0.5 -15 1323 No stop 09 31 00 =2229-172 22 31 26 12.6 539.5 -0.0 -0.3 105 1354 09 29 01 09 31 00 TXS 22 31 26 11.4 540.3 0.0 0.1 -15 1354 No stop 09 34 00 --- 22 34 27 11.4 541.0 0.1 0.5 165 1400 09 31 01 09 34 30 J2232-1659 22 34 57 12.6 540.4 0.0 0.2 15 1400 09 34 30 09 36 30 =2229-172 22 36 57 12.6 540.9 0.1 0.4 120 1431 09 34 31 09 36 30 TXS 22 36 57 11.4 541.6 0.1 0.8 -15 1431 No stop 09 39 30 --- 22 39 57 11.4 542.3 0.2 1.2 165 1477 09 36 31 09 39 30 J2232-1659 22 39 57 12.6 541.6 0.1 0.8 -15 1477 No stop 09 41 30 =2229-172 22 41 58 12.6 542.1 0.1 1.1 105 1508 09 39 31 09 41 30 TXS 22 41 58 11.4 542.8 0.2 1.5 -15 1508 No stop 09 44 30 --- 22 44 58 11.3 543.6 0.2 1.8 165 1554 09 41 31 09 45 00 J2232-1659 22 45 28 12.6 542.9 0.2 1.5 15 1554 09 45 00 09 47 00 =2229-172 22 47 29 12.5 543.4 0.2 1.8 120 1585 09 45 01 09 47 00 TXS 22 47 29 11.3 544.2 0.3 2.2 -15 1585 No stop 09 50 00 --- 22 50 29 11.3 544.9 0.3 2.5 165 1631 09 47 01 09 50 00 J2232-1659 22 50 29 12.5 544.2 0.3 2.1 -15 1631 No stop 09 52 00 =2229-172 22 52 30 12.5 544.7 0.3 2.4 105 1662 09 50 01 09 52 00 TXS 22 52 30 11.3 545.4 0.4 2.8 -15 1662 No stop 09 55 00 --- 22 55 30 11.2 546.1 0.4 3.2 165 1708 09 52 01 Schedule for SVETLOE (Code Sv ) Page 5 A definite answer to the nature of the water gigamaser in TXS2226-184 UP: D => Below limits; H => Below horizon mask; W => still slewing at end; blank => Up. Early: Seconds between end of slew and start. Dwell: On source seconds. Disk: GBytes recorded to this point. TPStart: Recording start time. Frequencies are LO sum (band edge). SYNC: Time correlator is expected to sync up. ---------------------------------------------------------------------------------------- Start UT Source Start / Stop Early Disk TPStart Stop UT LST EL AZ HA UP ParA Dwell GBytes SYNC ---------------------------------------------------------------------------------------- --- Sun 7 Mar 2021 Day 66 --- 09 55 30 J2232-1659 22 56 00 12.5 545.5 0.4 2.8 15 1708 09 55 30 09 57 30 =2229-172 22 58 00 12.4 546.0 0.4 3.1 120 1738 09 55 31 09 57 30 TXS 22 58 00 11.2 546.7 0.5 3.5 -15 1738 No stop 10 00 30 --- 23 01 01 11.1 547.4 0.5 3.8 165 1785 09 57 31 10 00 30 J2232-1659 23 01 01 12.4 546.7 0.5 3.5 -15 1785 No stop 10 02 30 =2229-172 23 03 01 12.4 547.2 0.5 3.7 105 1815 10 00 31 10 02 30 TXS 23 03 01 11.1 547.9 0.5 4.1 -15 1815 No stop 10 05 30 --- 23 06 02 11.1 548.6 0.6 4.5 165 1862 10 02 31 10 06 00 J2232-1659 23 06 32 12.3 548.1 0.6 4.1 15 1862 10 06 00 10 08 00 =2229-172 23 08 32 12.3 548.6 0.6 4.4 120 1892 10 06 01 10 08 00 TXS 23 08 32 11.0 549.3 0.6 4.8 -15 1892 No stop 10 11 00 --- 23 11 33 11.0 550.0 0.7 5.1 165 1938 10 08 01 10 11 00 J2232-1659 23 11 33 12.2 549.3 0.6 4.8 -15 1938 No stop 10 13 00 =2229-172 23 13 33 12.2 549.8 0.7 5.0 105 1969 10 11 01 10 13 00 TXS 23 13 33 10.9 550.5 0.7 5.4 -15 1969 No stop 10 16 00 --- 23 16 33 10.8 551.2 0.8 5.8 165 2015 10 13 01 10 16 30 J2232-1659 23 17 04 12.1 550.7 0.7 5.5 15 2015 10 16 30 10 18 30 =2229-172 23 19 04 12.0 551.1 0.8 5.7 120 2046 10 16 31 10 18 30 TXS 23 19 04 10.8 551.8 0.8 6.1 -15 2046 No stop 10 21 30 --- 23 22 04 10.7 552.5 0.9 6.4 165 2092 10 18 31 10 21 30 J2232-1659 23 22 04 12.0 551.9 0.8 6.1 -15 2092 No stop 10 23 30 =2229-172 23 24 05 11.9 552.4 0.8 6.3 105 2123 10 21 31 10 23 30 TXS 23 24 05 10.6 553.0 0.9 6.7 -15 2123 No stop 10 26 30 --- 23 27 05 10.6 553.7 0.9 7.0 165 2169 10 23 31 10 27 00 J2232-1659 23 27 35 11.8 553.2 0.9 6.8 15 2169 10 27 00 10 29 00 =2229-172 23 29 36 11.8 553.7 0.9 7.0 120 2200 10 27 01 10 29 00 TXS 23 29 36 10.5 554.3 1.0 7.4 -15 2200 No stop 10 32 00 --- 23 32 36 10.4 555.0 1.0 7.7 165 2246 10 29 01 10 32 00 J2232-1659 23 32 36 11.7 554.4 1.0 7.4 -15 2246 No stop 10 34 00 =2229-172 23 34 36 11.6 554.9 1.0 7.6 105 2277 10 32 01 Schedule for SVETLOE (Code Sv ) Page 6 A definite answer to the nature of the water gigamaser in TXS2226-184 UP: D => Below limits; H => Below horizon mask; W => still slewing at end; blank => Up. Early: Seconds between end of slew and start. Dwell: On source seconds. Disk: GBytes recorded to this point. TPStart: Recording start time. Frequencies are LO sum (band edge). SYNC: Time correlator is expected to sync up. ---------------------------------------------------------------------------------------- Start UT Source Start / Stop Early Disk TPStart Stop UT LST EL AZ HA UP ParA Dwell GBytes SYNC ---------------------------------------------------------------------------------------- --- Sun 7 Mar 2021 Day 66 --- 10 34 00 TXS 23 34 36 10.3 555.5 1.1 8.0 -15 2277 No stop 10 37 00 --- 23 37 37 10.2 556.2 1.1 8.3 165 2323 10 34 01 10 37 30 J2232-1659 23 38 07 11.5 555.8 1.1 8.0 15 2323 10 37 30 10 39 30 =2229-172 23 40 07 11.4 556.3 1.1 8.3 120 2354 10 37 31 10 39 30 TXS 23 40 07 10.1 556.8 1.2 8.6 -15 2354 No stop 10 42 30 --- 23 43 08 10.0 557.6 1.2 9.0 165 2400 10 39 31 10 42 30 J2232-1659 23 43 08 11.3 557.0 1.2 8.6 -15 2400 No stop 10 44 30 =2229-172 23 45 08 11.3 557.5 1.2 8.9 105 2431 10 42 31 10 48 00 J2232-1659 23 48 39 11.1 558.3 1.3 9.3 203 2431 10 48 00 10 50 00 =2229-172 23 50 39 11.0 558.8 1.3 9.5 120 2462 10 48 01 10 53 00 J2232-1659 23 53 40 10.9 559.5 1.3 9.9 173 2462 10 53 00 10 55 00 =2229-172 23 55 40 10.8 560.0 1.4 10.1 120 2492 10 53 01 10 58 30 J2232-1659 23 59 10 10.7 560.8 1.4 10.5 203 2492 10 58 30 11 00 30 =2229-172 00 01 11 10.6 561.3 1.5 10.8 120 2523 10 58 31 11 03 30 J2232-1659 00 04 11 10.5 562.0 1.5 11.1 173 2523 11 03 30 11 05 30 =2229-172 00 06 12 10.4 562.5 1.5 11.4 120 2554 11 03 31 11 09 00 J2232-1659 00 09 42 10.2 563.3 1.6 11.8 203 2554 11 09 00 11 11 00 =2229-172 00 11 42 10.1 563.8 1.6 12.0 120 2585 11 09 01 11 23 15 3C48 00 24 00 60.1 507.4 -1.2 -18.5 621 2585 11 23 15 11 30 15 --- 00 31 01 60.6 510.2 -1.1 -17.0 420 2692 11 23 16 12 34 35 3C454.3 01 35 31 37.2 591.0 2.7 23.5 3773 2692 12 34 35 12 39 35 --- 01 40 32 36.7 592.4 2.8 23.9 300 2769 12 34 36 14 24 25 3C454.3 03 25 39 25.0 618.6 4.5 30.1 6281 2769 14 24 25 14 30 00 --- 03 31 15 24.4 619.8 4.6 30.3 335 2855 14 24 26 SETUP FILE INFORMATION: NOTE: If DOPPLER, FREQ, or BW were used, see the individual scans for the final BBC settings. ======== Setup file: sess121.C2048 Matching groups in /home/guest/rmc/SCHED/sched11.6/catalogs/freq_RDBE.dat: kvzr_c Added by Des Small, 24 February 2012 Setup group: 1 Station: SVETLOE Total bit rate: 2048 Format: MARK5B Bits per sample: 2 Sample rate: 64.000 Number of channels: 16 DBE type: Speedup factor: 1.00 Disk used to record data. 1st LO= 4500.00 4500.00 4500.00 4500.00 4500.00 4500.00 4500.00 4500.00 4500.00 4500.00 4500.00 4500.00 4500.00 4500.00 4500.00 4500.00 Net SB= L L U U L L U U L L U U L L U U IF SB = U U U U U U U U U U U U U U U U Pol. = RCP LCP RCP LCP RCP LCP RCP LCP RCP LCP RCP LCP RCP LCP RCP LCP BBC = 1 9 1 9 2 10 2 10 3 11 3 11 4 12 4 12 BBC SB= L L U U L L U U L L U U L L U U IF = A B A B A B A B A B A B A B A B The following frequency sets based on these setups were used. Frequency Set: 9 Setup file default. Used with PCAL = off LO sum= 4830.49 4830.49 4830.49 4830.49 4894.49 4894.49 4894.49 4894.49 4958.49 4958.49 4958.49 4958.49 5022.49 5022.49 5022.49 5022.49 BBC fr= 330.49 330.49 330.49 330.49 394.49 394.49 394.49 394.49 458.49 458.49 458.49 458.49 522.49 522.49 522.49 522.49 Bandwd= 32.00 32.00 32.00 32.00 32.00 32.00 32.00 32.00 32.00 32.00 32.00 32.00 32.00 32.00 32.00 32.00 Matching frequency sets: 9 10 11 Track assignments are: track1= 18, 26, 2, 10, 20, 28, 4, 12, 22, 30, 6, 14, 24, 32, 8, 16 barrel=roll_off POSITIONS OF SOURCES USED IN RECORDING SCANS Source Source position (RA/Dec) Error (B1950) (J2000) (Date) (mas) * TXS 22 26 30.065630 * 22 29 12.494600 22 30 18.881967 0.00 -18 26 09.57617 *-18 10 47.24200 -18 04 28.99753 0.00 From catalog imbedded in main SCHED input file. J0137+3309 01 34 49.826374 * 01 37 41.299440 01 38 51.768519 0.52 0134+329 32 54 20.25881 * 33 09 35.13299 33 15 56.63291 0.50 * 3C48 /home/guest/rmc/SCHED/sched11.6/catalogs/sources.vlba.2012jul J0137+33 rfc_2012b Petrov, 2012, unpublished 140 observations J1642+3948 16 41 17.606228 * 16 42 58.809965 16 43 41.199694 0.77 * 3C345 39 54 10.81496 * 39 48 36.99402 39 45 58.75868 0.52 1641+399 /home/guest/rmc/SCHED/sched11.6/catalogs/sources.vlba.2012jul J1642+39 GSFC 2011B astro solution 52621 Observations * J2232-1659 22 29 40.999940 * 22 32 22.564554 22 33 28.600541 0.26 2229-172 -17 14 29.56607 *-16 59 01.89249 -16 52 41.60980 0.43 /home/guest/rmc/SCHED/sched11.6/catalogs/sources.vlba.2012jul rfc_2012b Petrov, 2012, unpublished 86 observations J2253+1608 22 51 29.519738 * 22 53 57.747937 22 54 58.244678 0.68 * 3C454.3 15 52 54.34810 * 16 08 53.56093 16 15 26.22048 0.72 2251+158 /home/guest/rmc/SCHED/sched11.6/catalogs/sources.vlba.2012jul J2253+16 GSFC 2011B astro solution 39747 Observations SOURCE SCAN SUMMARY FOR SOURCES LISTED ABOVE Scan hours are for recording scans only. Baseline hours are only counted for scans above horizon at both ends. Source Setup file Frequency sets Observing hours (duplicates not shown) Scan Baseline TXS sess121.C2048 1 2 3 4 5 6 7 8 9 13 18 19 + 3.500 337.788 3C48 sess121.C2048 1 2 3 4 5 6 7 8 9 13 18 19 + 0.117 22.154 3C345 sess121.C2048 1 2 3 4 5 6 7 8 9 13 0.133 18.133 J2232-1659 sess121.C2048 1 2 3 4 5 6 7 8 9 13 18 19 + 2.417 251.118 3C454.3 sess121.C2048 1 2 3 4 5 7 8 9 13 19 0.176 21.167 EFFECT OF SOLAR CORONA The solar corona can cause unstable phases for sources too close to the Sun. SCHED provides warnings at individual scans for distances less than 10 degrees. The distance from the Sun to each source in this schedule is: Source Sun distance (deg) TXS 16.6 3C48 51.7 3C345 98.8 J2232-1659 15.2 3C454.3 21.8 Barry Clark estimates from predictions by Ketan Desai of IPM scattering sizes that the Sun will cause amplitude reductions on the longest VLBA baselines at a solar distance of 60deg F^(-0.6) where F is in GHz. For common VLBI bands, this is: 327 MHz 117. deg 610 MHz 81. deg 1.6 GHz 45. deg 2.3 GHz 36. deg 5.0 GHz 23. deg 8.4 GHz 17. deg 15.0 GHz 12. deg 22.0 GHz 9. deg 43.0 GHz 6. deg