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