Lens System Summary
B2114+022 was discovered in the JVAS survey, although difficulties in confirming it as a lens system held back publication of its discovery. As argued in Augusto et al. and Chae, Mao and Augusto, the system is an example of multi-plane lensing, where two galaxies at different redshifts lens the background source. The nearer lens (G1) is a post-starburst (E+A) galaxy, while the more distant galaxy (G2) appears to be an elliptical. Components A and D are regarded as the multiple images of the background source, while B and C are considered to be emission connected with G1.
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This Lens System
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Lens name
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B2114+022
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Survey
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JVAS
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Images
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2
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B1950.0 coords
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21h14m18.745s
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02°13'11.040"
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J2000.0 coords
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21h16m50.740s
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02°25'46.270"
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Lens System Structure and Labelling
Image labelling for this lens (RA increases to the left, declination increases upwards)
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Image/Lens Positions
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Image/Lens
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Relative Position
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East (mas)
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North (mas)
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A
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0.0
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0.0
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B
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175±1
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333±1
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C
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397±1
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43±1
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D
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2286±1
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1158±2
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G1
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555±10
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40±10
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G2
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700±10
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1336±10
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Image/Lens Separations
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Separation (mas)
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Component
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A
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B
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C
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D
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G1
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G2
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A
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376.2
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399.3
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2562.6
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556.4
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1508.3
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B
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376.2
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365.2
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2266.5
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479.8
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1132.1
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C
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399.3
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365.2
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2193.5
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158.0
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1328.0
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D
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2562.6
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2266.5
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2193.5
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2060.7
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1596.0
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G1
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556.4
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479.8
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158.0
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2060.7
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1304.1
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G2
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1508.3
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1132.1
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1328.0
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1596.0
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1304.1
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Position angle (°)
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Component
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A
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B
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C
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D
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G1
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G2
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A
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-152.3
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-96.2
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-116.9
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-94.1
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-152.3
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B
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27.7
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-37.4
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-111.3
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-52.4
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-152.4
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C
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83.8
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142.6
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-120.6
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-88.9
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-166.8
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D
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63.1
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68.7
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59.4
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57.1
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96.4
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G1
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85.9
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127.6
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91.1
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-122.9
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-173.6
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G2
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27.7
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27.6
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13.2
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-83.6
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6.4
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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.
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Radio Flux Densities
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Component
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Flux density (mJy)
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1.6 GHz
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1.6 GHz
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5 GHz
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5 GHz
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5 GHz
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8.4 GHz
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15 GHz
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A
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73.2±2
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45
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44
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66.0±2
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65
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38.0±1
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18.8±1
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B
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32.6±2
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28
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37
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53.4±2
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52
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36.2±1
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18.5±1
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C
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13.0±1
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20
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16.1±1
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16
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13.1±1
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6.4±1
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D
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29.6±1
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26
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16
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20.4±1
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21
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12.5±1
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7.1±1
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Flux errors
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Resolution (mas)
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180
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20
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3
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50
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50
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200
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110
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Map noise level
(mJy/beam)
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0.075
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Instrument
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MERLIN
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EVN+MERLIN
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VLBA
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MERLIN
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MERLIN
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VLA
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VLA
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Date observed
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1993/09/27
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1997/05/31
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1995/11/12
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1995/06/02
1995/06/04
1995/06/14
1996/12/26
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1995/06/02
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1992/10/18
1995/08/08
1995/08/24
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1995/08/08
1995/08/24
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Reference
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[2]
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[2]
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[2]
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[2]
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[2]
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[2]
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[2]
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Sub-millimetre Flux Densities
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Component
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Flux density (mJy)
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850 μm
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Total
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<4.3
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Estimated
cal. error
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5-10%
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Instrument
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SCUBA (JCMT)
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Date observed
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1999-2001
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Reference
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[4]
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Optical Imaging
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Component
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Brightness (Magnitudes)
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K
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V (555nm)
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I (814nm)
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H (F160W)
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G1
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20.6±0.1
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19.0±0.1
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17.0±0.1
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G2
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21.9±0.1
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19.5±0.1
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17.3±0.1
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Radio Images
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>25
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>23
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Instrument
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NIRC (Keck)
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WFPC2 (HST)
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WFPC2 (HST)
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NICMOS (HST)
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Integration time
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20 min
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1000 sec
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3000 sec
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5250 sec
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PSF size (arcsec)
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0.8
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0.05
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0.05
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0.13
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Pixel scale (mas/pixel)
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50
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50
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130
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Date observed
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1996/07/31
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1997/07/03
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1997/07/03
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1997/08/28
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Reference no.
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[2]
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[2]
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[2]
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[2]
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Redshifts
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Object
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Redshift
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Instrument
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Date Observed
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Reference
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G1
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0.3157±0.0003
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LRIS (Keck II)
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1997/07/26
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[2]
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G2
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0.5883±0.0003
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LRIS (Keck II)
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1997/07/26
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[2]
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Lens Models
Click on the model's reference number to go to the relevant paper's abstract on ADS.
[2] Augusto et al. use two models; SIS (G1) + external shear (G2), and a single SIE (G1). Neither are satisfactory. Both have zero D.O.F. Both suggest that any external shear is not solely due to G2.
[3] Chae, Mao and Augusto undertake extensive modelling of this lens system, treating it as a case of multiple-plane lensing.
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Notes
Multi-plane lens?
No evidence for variability above 10% level over several years.
Astrometry obtained using NOT CCD image and Carlsberg Automatic Meridian Circle measurements. Estimated NICMOS H/MERLIN 5GHz data registration error is 0.1 arcsec.
Component D coincides with single bad NICMOS pixel, as identified in NICMOS images of other lenses.
Components A and D have similar surface brightnesses. B and C have similar surface brightnesses (different from A and D). A and D appear <10mas in size, while B and C are extended on >10mas scales.
G1 classified as a starburst (E+A) galaxy. G2 is an elliptical galaxy.
No sign of optical or IR emission from components A to D down to I = 25 and H = 23. D is separated from G1 by 2 arcsec, so absorption of emission from D by G1 considered unlikely.
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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.
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[1] Gravitationally lensed radio sources in the Jodrell Bank-VLA Astrometric Survey, L. J. King et al., Mon. Not. R. Astron. Soc. 307, pp. 225-235 (1999)
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[2] B2114+022: a distant radio source gravitationally lensed by a starburst galaxy, P. Augusto et al., Mon. Not. R. Astron. Soc. 326, p. 1007 (2001)
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[3] Modelling the first probable two-plane lens system B2114+022: reproducing two compact radio cores A and D, K.H Chae, S. Mao and P. Augusto, Mon. Not. R. Astron. Soc 326, p. 1015 (2001)
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[4] A submillimeter survey of gravitationally lensed quasars, R. Barvainis and R. Ivison, Astrophys. J. 571, pp. 712-720 (2002)
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