A growth curve is first derived for each object by integrating
the counts in concentric circular rings of increasing diameter,
centered at the coordinates given in Table 1 (click here).
The obtained H band growth curves, transformed from counts
to magnitudes, are compared with the multiaperture photometry
available from the literature, in order to check
our photometric calibration.
Figures 3 (click here)a-c give the H band growth curves
of NGC 2366, NGC 2403 and NGC 4236 respectively.
These measurement were obtained after subtracting all stars
in the fields.
The maximum diameters shown are set by the limiting
surface brightness given in Table 2 (click here).
The aperture photometry of AA80 is also shown in the figures
(open stars).
Figure 3: H band growth curves of NGC 2366 a), NGC 2403 b),
NGC 4236 c). (Filled squares = this work; open stars = AA80
reference aperture photometry - see text)
For NGC 2366, our and the reference photometric
points are in satisfactory agreement.
For NGC 2403 the agreement between our measurement
and the reference ones is satisfactory within an aperture
of 200 arcsec.
At larger diameters our growth curve is fainter
than that of AA80 by 0.3 mag.
AA80 photometry is obtained after removal of the 2 bright stars
near the nucleus, while our is obtained with subtraction
of all stars. The discrepancy reduces to 
0.1 mag
if we use similar star removal criteria.
For NGC 4236 the discrepancy with the reference photometry
is 0.35 mag (only 0.1 mag due to star removal).
Since the 
measurements, which cannot be compared
with previous photometry, were done in close sequence
with the H ones, we assume that they are as well calibrated.
A comparison between the extrapolated magnitudes adopted by AA80
and the results of the present work are summarized in Table 3 (click here).
At a-0.5 adopted by AA80 (Col. 2), H-0.5
as given by AA80 is listed in Col. 3 together with the value
derived in this work (Col. 4).
Column 5 lists 
.
Using the star-subtracted frames, the surface brightness profiles
are determined by averaging the brightness distribution
in concentric elliptical annuli of fixed center, position angle
and ellipticity. The position angle and ellipticity of the ellipse
were determined from the H band 21 mag arcsec-2 isophotes
of the galaxy under study. For NGC 2366 and NGC 2403 the latter
quantity corresponds to the one determined optically.
For NGC 4236 we adopt the optical ellipticity.
For several reasons we prefer this rather simple procedure
to the more sophisticated ones in which the parameters
of the fitted ellipses are not kept constant because:
i) for spiral-Irr galaxies isodensity contours
cannot be fitted with ellipses (see also de Jong & van der Kruit
1994);
ii) an accurate error analysis requires keeping track
of parameters such as the area of the ellipse,
which is not done by the more sophisticated tools available in IRAF.
Starting from an inner ellipse of size comparable with
the seeing disk,
we draw a set of annuli, increasing the major axis by fixed amounts.
In each ring we compute the total number of counts
and the total number of pixels.
The statistical uncertainties on the net counts in each annulus
are computed as in Gavazzi et al. (1994).
The photometric parameters determined along elliptical rings
are summarized in Table 4 (click here), as follows:
Column 1: NGC name;
Column 2: Position Angle of the galaxy major axis
(measured Eastwards from North) used to derive
the surface brightness profiles;
Column 3: ellipticity (1-b/a) of the rings
used to derive the surface brightness profiles;
Column 4: projected distance in arcsec along the major axis,
truncated at the radius corresponding to a surface brightness
equivalent to 1 
of the sky;
Columns 5-6: H band surface brightness and integrated magnitude;
Columns 7-8: band surface brightness
and integrated magnitude.
These magnitudes are measured quantities and are not corrected
to the face-on value.
Figure 4 (click here) gives the differential H and profiles
in mag arcsec-2, obtained by azimuthal integration along elliptical annuli
and the differential 
color profile.
The horizontal scale of panels B and C gives the projected distance
in arcsec as measured from the galaxy center along the major axis
of the ellipse.
The profiles are truncated at the limiting surface brightness
of Table 2 (click here).
The wiggles bteween 70 and 120 arcsec in the profiles of NGC 2366
are due to HII regions.
The color index for the three galaxies is in
agreement with 
found by Boselli et al. (1997) for Virgo galaxies.
Columns 6 and 7 of Table 3 (click here)
list the H and band asymptotic magnitudes,
with their uncertainties (including the zero point and the error
introduced by the extrapolation to infinity).
An exponential disk was fit to the radial surface brightness profile
in the intermediate radial range, where the profile shows
an exponential shape.
The total magnitude was computed by integrating the counts
along elliptical annuli up to the last useful radius
(see Cols. 5 and 7 of Table 4 (click here)) and by adding the the contribution
derived from the exponential fit from this radius to infinity.
Figure 4: Light profiles of NGC 2366 a), NGC 2403 b), NGC
4236 c). (Filled squares =K' data; crosses =H data)
Acknowledgements
We thank the MAGIC team at MPI für Astronomie for their skilful operational support and for several helpful discussions about data reduction. A.B. is supported by a stipendium from the Deutsche Argentur für Raumfartengelegenheiten (DARA), GmbH, Bonn, Germany, (grant # 50-OR-95018).