# Configuration file for imfit, for use in fitting central 800x800 (or 800x1600) pixels of
# ACS/WFC F475W image using:
# 2 EdgeOnDisk_n4762v2 objects + EdgeOnRing + Sersic (bulge) + nucleus

# For individual functions, position angles ("PA") are in degrees counter-clockwise
# from vertical, "ell" = ellipticity = 1 - b/a, sizes are in pixels, and intensities
# (e.g. "I_e", "I_0", etc.) are in counts/pixel

# image characteristics for F475W ACS image
GAIN	1.0             # e-/ADU
READNOISE	5.0         # e-
ORIGINAL_SKY	42.63   # counts/pixel (this value was subtracted from the image)


# these are the common coordinates for component centers:
#param  initial-value  lower,upper limits
X0    2663.41   2661,2667
Y0    2657.80   2654,2660

FUNCTION Gaussian   # for unresolved nucleus (possibly nuclear star cluster?)
PA      0     fixed
ell     0.0   fixed
I_0     10000.0  0,2e5
sigma	0.2	0.01,2.0

FUNCTION   Sersic   # for the bulge
PA     90.0      88,92
ell	0.20	0,0.4
n	2.3	0.5,4.0
I_e	1200.0	100,3000
r_e	85.0	0,150

# The next two components use the same 2D function: an edge-on disk with
# a vertical exponential profile and a horizontal "broken-exponential" profile,
# where the break radius is a linear function of height
FUNCTION   EdgeOnDisk_n4762v2   # inner ("thin") edge-on disk component
PA     90.0      88,92
I_0    1400.0   0,5000
h_2     800.0   500,2000
a_rb   20.0      0,200
b_rb   1.2       0,10
alpha   1.0     fixed
h_z     75.0    40,120

FUNCTION   EdgeOnDisk_n4762v2   # outer ("thick") edge-on disk component
PA     90.0      88,92
I_0     150.0   0,5000
h_2     500.0   200,2000
a_rb   60.0      0,200
b_rb   1.2       0,10
alpha   1.0     fixed
h_z    300.0    150,500

FUNCTION   EdgeOnRing2Side     # nuclear ring: two asymmetric Gaussians, reflected about center
PA     90.0      88,92
I_0     700.0   0,1200
r      45.0     0,70
sig_r_in  20.0     0,60
sig_r_out  14.0     0,60
sig_z  13.0     0,60