IV. 2MASS Data Processing

5. Extended Source Identification and Photometry

e. Large Aperture Photometry: Profile Fitting, Isophotal and Total Magnitudes

i. Examples of Radial Profile Fitting

Below are some examples of the radial profile fitting technique. The layout for all the image figures is as follows:

Upper panel: J, H, K_s (Postage Stamp) images
Lower panel: Same, but with stars subtracted

The color code for the elliptical contours shown on the image figures is as follows:

yellow = half-light ("effective") aperture
blue = 3- aperture
magenta = 20 mag arcsec^-2 aperture
orange = Kron aperture (2.5 * first moment diameter)
red = subtracted stars

The color code for the corresponding K_s-band surface brightness profiles is as follows:

white points == mean surface brightness (log units)
green points == points used in the profile fit
red dashed line == solution
yellow line == half-light ("effective") radius
magenta line == 20 mag arcsec^-2 radius
orange line == Kron radius (2.5 * first moment radius)
grey == integration radius for first moment determination

Object 1, J = 11.85, H = 11.32, K_s = 11.04 mag.

Figure 1	Figure 2

Object 2, J = 11.47, H = 10.76, K_s = 10.42 mag.

Figure 3	Figure 4

Object 3, J = 11.89, H = 11.16, K_s = 10.86 mag.

Figure 5	Figure 6

Object 4, J = 12.51, H = 11.90, K_s = 11.58 mag.

Figure 7	Figure 8

Object 5, J = 14.30, H = 13.51, K_s = 13.04 mag.

Figure 9	Figure 10

Object 6, J = 14.46, H = 13.73, K_s = 13.44 mag.

Figure 11	Figure 12

Object 7, J = 14.98, H = 14.14, K_s = 13.58 mag.

Figure 13	Figure 14

[Last Updated: 2002 Jul 15; by Tom Jarrett]