HST 16302+8230

Observed	HST Model	MLE Model	Residual	Lensed source	Filter
					F814W i5.m0
					F606W v3.m0
					F450W b7.m0

HST 16302+8230 could be an ``Einstein ring'' but clearly needs spectroscopic confirmation, since it may also be a polar ring galaxy.
In our opinion it is the least probable of our top ten candidate list but the most intriguing. It has been nicknamed the ``the London Underground'' since it resembles that logo.
The right half of the the image is much fainter for an unknown reason. The ``ring'' is clearly much bluer than the central galaxy.
The edge-on disk lensing galaxy is barely visible in the V band and was not detected in the B band which just shows a part of the ring.
If it is a lensed source, then it appears to be extended with a color (V-I)=0.9 mag.
The impact radius is 0".14.
The image magnification is about 2.1 magnitudes.
The model gives a reasonably good fit with a normalized chi² close to unity.

Name	HST 16302+8230
Equatorial(J2000)	16:30:12.9		+82:29:59		PA_V3=353^o.22
HST WFPC2	GROTH GTO-PAR:6254 1996-Jun-06
Dataset[g][x,y]	U203T[2][110,590]
MDS Field:id lens galaxy	urg01:0042
HST WFPC2 Filter	F814W		F606W		F450W
Exposure seconds	5 x 1100		3 x 900		7 x 1157
log (integrated S/N Ratio)	2.72		2.40		1.71
Fitted Parameter	MLE	+/- rms	MLE	+/- rms	MLE	+/- rms
Sky Mag. (arcsec²)	21.898	0.003	22.371	0.002	23.133	0.007
Total Mag of lens galaxy	23.72	0.13	25.70		Dropout	-
X centroid 0".1 Pix	110.52	0.08	110.26	0.09	109.66	0.36
Y centroid 0".1 Pix	591.75	0.05	591.81	0.06	592.69	0.18
Half-light radius	1".398	0".034	-	-	-	-
Orientation of light	75^o.0	1^o.6	-	-	-	-
Axis Ratio of the light	0.11	0.03	-	-	0.06	0.12
Mag. of lensed source	24.93	0.08	25.82	0.06	27.06	0.17
Source X offset 0".1 Pix	0.46	0.03	0.46	Fixed	0.46	Fixed
Source Y offset 0".1 Pix	1.34	0.05	1.34	Fixed	1.34	Fixed
Critical Radius	0".734	0".004	0".734	Fixed	0".734	Fixed
Axis Ratio Lens mass	0.86	0.02	0.86	Fixed	0.86	Fixed
Lens Orientation	- 79^o.0	2^o.9	- 79^o.0	Fixed	- 79^o.0	Fixed
Source half-light	0".290	0".022	0".290	Fixed	0".290	Fixed
Source Orientation	63^o.0	18^o.6	62^o.2	Fixed	62^o.2	Fixed
Source Axis-Ratio	0.74	0.10	0.74	Fixed	0.74	Fixed

Lens galaxy from MDS-Pipeline fit