Central wavelengths and zero points

Here is a large collection of central wavelengths and zero points, useful for converting between flux densities and magnitudes, which then enables adding points into an SED, or making a color-mag diagram (depending on whether you are starting from mags or flux densities).

band     wavelength (um)    zero point (Jy)
 J            1.25           1594
 H            1.65           1024
 Ks           2.17            666.7  Kshort not Johnson K!

 I1           3.6             280.9
 I2           4.5             179.7
 I3           5.8             115.0
 I4           8.0              64.13
 M1           24                7.14
 M2           70                0.775
 M3          160                0.159

 W1           3.4             309.54
 W2           4.6             171.79
 W3          12                31.676
 W4          22                 8.3635

 U           0.36            1755
 B           0.44            4000.87
 V           0.55            3597.28
 Rc          0.71            3080     !! Cousins R (not the same as Johnson R)!
 Ic          0.79            2432.84  !! Cousins I (not the same as Johnson I)!

 sloan u    2910*1d-4        see below    !! 2910 A, and there are 10^-4 um per A. (etc for rest)
 sloan g    4810*1d-4
 sloan r    6230*1d-4
 sloan i    7640*1d-4
 sloan z    9060*1d-4

 iphas rprime  0.624         2515.7
 iphas ha      0.656         2974.4
 iphas iprime  0.774         3173.3

 akari band 1   9                   !! AKARI reports things already in fluxes. Generally, don't trust any other akari bands.
 akari band 2  18

BE CAREFUL to keep track of whether you are working with Vega-based magnitudes or AB mags. Vega magnitudes define things with respect to a Vega spectrum (see Units page), but some folks (largely extragalactic folks) define things with respect to a flat spectrum source instead, and those are AB mags. Most Sloan folks (even those folks working with stars) work in AB mags instead. For AB mags, you always use a flat reference spectrum, so the zero point is 3631 Jy for all bands.

More on filters and bandpasses