HST 18078+4600

Observed	HST Model	MLE Model	Residual	Lensed source	Filter
					F814W i2.m0
					F606W v2.m0
					F450W b4.m0

HST 18078+4600 is an arc caused by the gravitational potential of a small group of 4 galaxies. Since the software at hand, assumed a single lensing galaxy, the outer two galaxy images were masked out in the image analysis which was used to derive the approximate lens model.
The two central galaxies, with a color (V-I)=2.0 mag, were merged in the model and were not detected in the B band.
The significantly distorted lensed source is extended with colors (V-I)=0.3 mag, and (B-V)=0.2 mag.
The image magnification is about 0.7 magnitudes.
The impact radius is 0.85 arc seconds.
The model gives a good fit in V and B with a normalized chi² just larger than unity, but a poor fit in F814W owing to the use of a single lens galaxy approximation in the model.

Name	HST 18078+4600
Equatorial(J2000)	18:07:46.7		+45:59:56		PA_V3= 56^o.36
HST WFPC2	GROTH GTO-PAR:5092 1995-Apr-27
Dataset[g][x,y]	U2807302T[3][364,506]
MDS Field:id lens galaxy	uqc00:0029
HST WFPC2 Filter	F814W		F606W		F450W
Exposure seconds	2 x 2100		2 x 900		4 x 1875
log (integrated S/N Ratio)	3.28		3.97		2.55
Fitted Parameter	MLE	+/- rms	MLE	+/- rms	MLE	+/- rms
Sky Mag. (arcsec²)	22.344	0.004	22.597	0.004	23.496	0.006
Total Mag of lens galaxy	20.66	0.02	22.60	0.09	Dropout	-
X centroid 0".1 Pix	506.04	0.02	506.07	0.07	506.	-
Y centroid 0".1 Pix	577.79	0.02	577.96	0.08	578.	-
Half-light radius	1".480	0".036	1".502	0".122	-	-
Orientation of light	0^o.9	1^o.0	0^o.6	2^o.9	-	-
Axis Ratio of the light	0.47	0.01	0.36	0.04	-	-
Mag. of lensed source	24.05	0.05	24.39	0.05	24.57	0.02
Source X offset 0".1 Pix	7.82	0.13	7.41	0.14	7.41	Fixed
Source Y offset 0".1 Pix	3.82	0.04	4.08	0.10	4.09	Fixed
Critical Radius	0".456	0".005	0".449	0".009	0".449	Fixed
Axis Ratio Lens mass	0.18	0.01	0.23	0.03	0.23	Fixed
Lens Orientation	- 74^o.7	0^o.4	- 71^o.9	1^o.0	- 71^o.7	Fixed
Source half-light	0".192	0".010	0".199	0".008	0".199	Fixed
Source Orientation	64^o.5	1^o.6	64^o.5	Fixed	64^o.5	Fixed
Source Axis-Ratio	0.20	Fixed	0.20	Fixed	0.20	Fixed

Lens galaxy from MDS-Pipeline fit