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CLASS B1933+503, a 10 image gravitational lens



Lens System Summary

This system is unique among the JVAS/CLASS lenses, in that it displays ten lensed images. Analysis of the radio spectra of the images has shown that there are three lensed sources. One is doubly imaged and the other two are quadruply imaged, for a grand total of ten images. This system therefore imposes an abundance of constraints on any putative lens models, an advantage utilised by Cohn et al. (2001) and Muñoz, Kochanek and Keeton (2001) to intensively investigate cusped mass models. Although only 9 images are individually named in this document, radio component 2 is regarded as two merging images.

This Lens System

Lens name B1933+503
Survey CLASS
Images 10
B1950.0 coords 19h33m11.109s 50°18'44.200"
J2000.0 coords 19h34m30.899s 50°25'23.220"

Lens System Structure and Labelling

Image labelling for this lens (RA increases to the left, declination increases upwards)

Images labelled as in Sykes et al.

Image/Lens Positions

Image/Lens Relative Position
East (mas) North (mas)
1 +834.5 +793.9
1a +942 +883
2 +519 +720
3 +8.0 +457.0
4 +0.0 +0.0
5 -134 -198
6 +627 -88
7 +795 +165
8 +283 -36

Image/Lens Separations

Separation (mas)
Component 1 1a 2 3 4 5 6 7 8
1
139.6 324.0 892.5 1151.8 1386.3 906.0 630.1 996.4
1a 139.6
453.3 1026.6 1291.1 1525.2 1020.8 732.9 1130.9
2 324.0 453.3
574.7 887.6 1126.6 815.2 619.8 792.0
3 892.5 1026.6 574.7
457.1 670.2 824.7 839.4 564.5
4 1151.8 1291.1 887.6 457.1
239.1 633.1 811.9 285.3
5 1386.3 1525.2 1126.6 670.2 239.1
768.9 997.4 447.4
6 906.0 1020.8 815.2 824.7 633.1 768.9
303.7 347.9
7 630.1 732.9 619.8 839.4 811.9 997.4 303.7
550.0
8 996.4 1130.9 792.0 564.5 285.3 447.4 347.9 550.0
Position angle (°)
Component 1 1a 2 3 4 5 6 7 8
1
-129.7 76.8 67.8 46.4 44.3 13.2 3.6 33.6
1a 50.3
68.9 65.5 46.9 44.9 18.0 11.6 35.6
2 -103.2 -111.1
62.8 35.8 35.4 -7.6 -26.4 17.3
3 -112.2 -114.5 -117.2
1.0 12.2 -48.6 -69.6 -29.2
4 -133.6 -133.1 -144.2 -179.0
34.1 -82.0 -101.7 -82.8
5 -135.7 -135.1 -144.6 -167.8 -145.9
-98.2 -111.3 -111.2
6 -166.8 -162.0 172.4 131.4 98.0 81.8
-146.4 98.6
7 -176.4 -168.4 153.6 110.4 78.3 68.7 33.6
68.6
8 -146.4 -144.4 -162.7 150.8 97.2 68.8 -81.4 -111.4

Maps and Images

Click on an image to see a larger JPEG version, or click on the accompanying text to download a gzipped FITS or PostScript file of the map or image. The images and maps are available in one gzipped file here. To see a DSS image of the region around this lens, click here - note that you will have to start the search manually by clicking on the 'Search' button.

Optical and IR images Click to see a larger version
HST V-band image
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HST I-band image
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LRIS R-band image
Radio maps Click to see a larger version
MERLIN 1.7GHz image (100 mas beam)
D. R. Marlow et al.
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MERLIN 5GHz image
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MERLIN 5GHz image (75 mas beam)
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MERLIN 5GHz image (100 mas beam)
Radio spectra Click to see a larger version
HI spectrum of lens
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Radio spectrum, component 1
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Radio spectrum, component 2
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Radio spectrum, component 3
Radio spectra continued Click to see a larger version
Radio spectrum, component 4
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Radio spectrum, component 5
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Radio spectrum, component 6
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Radio spectrum, component 7

Radio Flux Densities

Component Flux density (mJy)
1.7 GHz 1.7 GHz 5 GHz 8.4 GHz 15 GHz
1 3.7 3.6 5.6 4.3 4.1
1a <0.19 0.9


2 35.9 23.0 8.3 4.4 3.5
3 <0.19 2.5 4.7 3.4 2.5
4 14.2 9.4 19.4 15.7 15.5
5 18.7 16.2 7.1 4.5 3.9
6 <0.19 2.2 5.4 3.6 3.2
7 20.4 20.3 8.2 5.2 4.4
8 3.6 3.6
0.5
Flux errors ~ ±0.4 mJy ±0.4 mJy ±0.4 mJy ±0.4 mJy ±0.4 mJy
Resolution (mas) 6 120 40, 1.5 200 130
Map noise level
(mJy/beam)
0.038



Instrument VLBA MERLIN MERLIN, VLBA VLA VLA
Date observed 1996/06/25 1995/10/27 1995/11/12
1995/06/23
1994/03/02
1995/07/06
1995/07/06
1995/08/28
Reference [4] [1] [1] [1] [1]

Optical Imaging

Component Brightness (Magnitudes)
F555W (~V) F814W (~I) F160W (~H)
1
>24.2 25.7
1a
>24.2 >28.0
2
>24.2 >28.0
3
>24.2 >28.0
4
>24.2 25.7
5
>24.2 >28.0
6
>24.2 >28.0
7
>24.2 >28.0
8
>24.2 >28.0
Lensing galaxy ~22.5 20.6±0.2 22
Instrument WFPC2 (HST) WFPC2 (HST) NIC1/NICMOS (HST)
Integration time 800 sec 1100 sec 10495 sec
PSF size (arcsec)

0.131
Pixel scale (mas/pixel)

43
Date observed 1995/11/11 1995/11/11 1997/10/09
Reference no. [1] [1] [4]

Redshifts

Object Redshift Instrument Date Observed Reference
Lens galaxy 0.755 LRIS (Keck) 1995/09/29 [1]
Source 2.638 CGS4 (UKIRT) 1999/06/09 [8]

Lens Models

Click on the model's reference number to go to the relevant paper's abstract on ADS.


[2]
Nair (1998) considered a triple-component radio source with a size of a few hundred mas as the lensed object. The predicted lensing galaxy position and position angle are in good agreement with the observed galaxy position and orientation using an SIE model for the lensing galaxy.

[6]
Cohn et al. (2001) modelled this system with selected cusped mass profiles.

[7]
Munoz, Kochanek and Keeton (2001) extended analysis to more general cusped mass models.

Notes

  1. Einstein ring present in IR - large arc visible in radio

  2. Component 2 believed to be two merging images.

  3. Tentative evidence for variability - monitoring underway (A. D. Biggs et al.)

References

Click here to see the CASTLES data available for this object, or here to search for references on NED. You can go to a paper's abstract on ADS by clicking its reference number.


[1] The complex gravitational lens system B1933+503, C. M. Sykes et al., Mon. Not. R. Astron. Soc. , pp. (1997)


[2] Modelling the 10-image lensed system B1933+503, S. Nair, Mon. Not. R. Astron. Soc. 301, Issue 2, pp. 315-322. (1998)


[3] B1933+503, a dusty radio quasar at z>2: implications for blank field sub-mm surveys?, S. C. Chapman et al., A&A 352, p. 406-414 (1999)


[4] NICMOS and VLBA observations of the gravitational lens system B1933+503, D. R. Marlow et al., Mon. Not. R. Astron. Soc. 305, Iss. 1, pp. 15-18 (1999)


[5] VLA 8.4-GHz monitoring observations of the CLASS gravitational lens B1933+503, Biggs, A. D., Mon Not. R. Astron. Soc. 318, Iss. 1, pp. 73-76 (2000)


[6] Constraints on Galaxy Density Profiles from Strong Gravitational Lensing: The Case of B1933+503, J. D. Cohn et al., Astrophys. J. 554, p. 1216 (2001)


[7] Cusped mass models of gravitational lenses, J. A. Muñoz, C. S. Kochanek and C. R. Keeton, Astrophys. J. 558, Iss. 2, pp. 657-665 (2001)


[8] PhD Thesis, M. Norbury (2002)

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