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ING filter effective bandwidths

The table at the end of this page gives the centroid wavelength and effective bandwidth (integral over T(l)dl where T(l) is transmission, l is wavelength) of each of the ING broad-band UBVR filters, calculated from Mariet Broxtermann's scans of T(l).

The last four columns give the centroid wavelength after multiplying the filter response curve by the detector response curve for the TEK2, EEV10, SIT1 and LOR1A CCDs (the changes are very small in BVR; in U, there is a significant shift to the red).

I've omitted I and Z filters from the table because the ING scanner is not reliable redward of 8500 A (the filters are being scanned by Mariet elsewhere). KP R1 appears to have an IR leak and has also been omitted.

Comparison between filters sets:

                centr +-  width +-                     centr +-  width +-
                  A        A                             A        A
B Harris         4330  5   720  15    KPNO B            4425 20   850  25
V Harris         5460 10   860  15    KPNO V            5445  5   770  50
R Harris         6470 15  1330  20    KPNO R            6470 10  1050  40

U1,3,6,7,8 50-mm 3550 20   500  20    WHT PF U 125-mm   3710      150
U INT WFC 125-mm 3590      490
'Harris' refers to the 50-mm sets, the WHT 125-mm and the INT WFC 139-mm filters.
  • The WHT PF U 125-mm filter has a factor 3 poorer throughput than the 50-mm U filters. A liquid-CuSO4 125-mm for WHT PF has been ordered from RGO and should arrive before the PF run in May 1998.
  • The KPNO B throughputs are up to 25% higher than for Harris B, because the bandpasses have higher peaks, are wider and have flatter tops.
  • The higher effective bandwidth of the Harris R filter is principally due a long redward tail (to 9000 A) in the transmission curve.
  • The ING measurements of the BVR Harris transmissions are similar to those given in LP technical note 73. The calculated effective bandwdths of the KPNO filters are similar to those given on p.15 of the INT PF Users' Manual.



                       Filter only         *TEK2   *EEV10  *SIT1   *LOR1A

Filter          File  Centre    Eff        Centre  Centre  Centre  Centre 
                      wave A   wid A       wave A  wave A  wave A  wave A

RGO U 25mm      f001   3550     364         3630    3580    3630    3580
RGO U1          f003   3540     542         3650    3590    3655    3585
RGO U3          f005   3550     500         3650    3595    3650    3595
RGO U5 125mm    f007   3710     154         3750    3730    3740    3730
RGO U6          f190   3530     542         3630    3570    3640    3570
RGO U7          f202   3570     478         3660    3610    3660    3610
RGO U8          f203   3570     485         3660    3610    3660    3610
RGO B1          f008   4340     555         4380    4355    4380    4355
RGO V1          f011   5340     643         5360    5340    5360    5340
RGO V2          f012   5365     623         5375    5360    5385    5365
RGO R1          f014   6470    1253         6450    6410    6460    6420
RGO R2          f015   6510    1285         6480    6445    6495    6460
Harris B1       f025   4330     706         4375    4350    4375    4350
Harris B2       f026   4330     741         4375    4350    4375    4350
Harris B3       f027   4335     728         4375    4355    4380    4355
Harris B4       f028   4325     710         4365    4345    4365    4345
Harris B5 125mm f029   4330     704         4370    4350    4370    4350
Harris B6 125mm f205   4325     690         4365    4345    4370    4345
Harris V1       f030   5475     890         5490    5470    5500    5475
Harris V2       f031   5460     857         5475    5455    5485    5460
Harris V3       f032   5460     852         5470    5455    5480    5460
Harris V4       f033   5450     855         5465    5445    5475    5450
Harris V5 125mm f034   5450     855         5460    5440    5470    5450
Harris V6 125mm f035   5420     875         5430    5410    5440    5410
Harris R1       f036   6495    1311         6465    6430    6485    6445
Harris R2       f037   6460    1317         6430    6390    6450    6410
Harris R3       f038   6460    1314         6430    6390    6450    6400
Harris R4       f039   6475    1365         6445    6400    6465    6415
Harris R5 125mm f040   6480    1344         6450    6410    6470    6420
KP B1           f046   4450     887         4480    4460    4490    4465
KP B2           f047   4395     834         4430    4410    4435    4410
KP B3           f048   4405     820         4435    4415    4440    4420
KP V1           f049   5445     822         5460    5440    5470    5445
KP V2           f050   5440     694         5450    5435    5455    5440
KP V3           f051   5450     837         5465    5445    5475    5450
KP R2           f053   6480    1086         6475    6450    6480    6455
KP R3           f054   6455    1015         6450    6430    6460    6435
Stromgr U       f178   3515     114         3535    3525    3535    3525
Stromgr V       f179   4120     101         4120    4120    4120    4120
Stromgr B       f180   4715     181         4715    4715    4715    4715
Stromgr Y       f181   5495     165         5495    5495    5495    5495
WFC RGO U       f204   3590     492         3670    3625    3665    3620
WFC Harr B      f191   4330     702         4370    4350    4370    4350
WFC Harr V      f192   5440     850         5460    5440    5470    5440
WFC Harr R      f193   6460    1323         6440    6400    6450    6410
WFC Stromgr U   f198   3480     154         3505    3490    3505    3490
WFC Stromgr V   f199   4105     102         4105    4105    4105    4105
WFC Stromgr B   f200   4700     169         4700    4695    4700    4700
WFC Stromgr Y   f201   5500     172         5500    5500    5500    5500



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Last modified: 25 April 2012