Lens System Summary
CLASS B0712+472 is a quadruple-image lens system. The redshift of the source is 1.339, that of the lens is 0.406. NICMOS images show that emission from the AGN host galaxy has been distorted by the lens galaxy.
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This Lens System
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Lens name
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B0712+472
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Survey
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CLASS
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Images
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4
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B1950.0 coords
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07h12m21.586s
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47°14'09.850"
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J2000.0 coords
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07h16m03.700s
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47°08'51.000"
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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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+51
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-160
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C
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+806
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-670
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D
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+1163
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+460
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Galaxy
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+775
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+150
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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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Galaxy
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A
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167.9
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1048.1
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1250.7
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789.4
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B
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167.9
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911.1
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1273.2
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787.6
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C
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1048.1
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911.1
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1185.1
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820.6
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D
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1250.7
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1273.2
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1185.1
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496.6
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Galaxy
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789.4
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787.6
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820.6
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496.6
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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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Galaxy
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A
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-17.7
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-50.3
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-111.6
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-101.0
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B
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162.3
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-56.0
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-119.1
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-113.2
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C
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129.7
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124.0
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-162.5
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177.8
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D
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68.4
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60.9
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17.5
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51.4
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Galaxy
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79.0
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66.8
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-2.2
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-128.6
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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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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+B
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26.5
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A
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15.3
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10.5
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10.7
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15.6
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B
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14.1
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8.5
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8.8
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11.6
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C
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6.9
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4.7
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3.6
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6.9
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5.9
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D
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2?
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0.9
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<1.0
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1.1
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Flux errors
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10-15%
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10-15%
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5%
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5%
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5%
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Resolution (mas)
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50
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50
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5
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220
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100
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Map noise level
(mJy/beam)
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0.25
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0.053
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0.15
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0.3
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0.12
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Instrument
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MERLIN
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MERLIN
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VLBA
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VLA
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VLA
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Date observed
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1995/03/09
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1996/11/15
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1995/11/12
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1994/03/02
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1995/08/28
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Reference
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[1]
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[1]
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[1]
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[1]
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[1]
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Sub-millimetre Flux Densities
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Component
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Flux density (mJy)
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3000 μm
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1300 μm
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850 μm
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Total
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22±0.4
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9.8±1.4
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7.4±1.8
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Estimated
cal. error
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5-10%
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Instrument
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PdBI (IRAM)
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PdBI + 30-m (IRAM)
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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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[4]
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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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V (F555W)
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I (F814W)
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H
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A
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23.8±0.1
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22.45±0.1
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20.11±0.06
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B
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25.0±0.1
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23.5±0.1
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21.05±0.15
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C
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24.8±0.1
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23.35±0.09
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21.05±0.15
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D
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>28
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28
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21.72±0.15
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Lensing galaxy
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22.2±0.1
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20.0±0.1
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17.5±0.15
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Instrument
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WFPC2 (HST)
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WFPC2 (HST)
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NIC1/NICMOS (HST)
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Integration time
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2 exp. of 2048sec
2 exp. of 576s
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PSF size (arcsec)
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Pixel scale (mas/pixel)
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45
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43
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Date observed
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1996/01/29
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1996/01/29
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1997/08/24
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Reference no.
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[1]
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[1]
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[3]
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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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Lens galaxy
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0.4060±0.0002
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LRIS (Keck)
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1997/02/06
1997/02/14
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[2]
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Source
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1.339±0.002
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LRIS (Keck)
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1997/02/06
1997/02/14
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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.
[1] SIE provides a poor fit to the observed images. PA of SIE found to be coincidental with that of observed lensing galaxy.
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Notes
Evidence for some radio variability.
Polarisation map derived from MERLIN data shows no polarisation at the 2-sigma level corresponding to 1% of the flux of A (Jackson et al. 1998).
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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] B0712+472: a new radio four-image gravitational lens, N. Jackson et al., Mon. Not. R. Astron. Soc. 296, Issue 3, pp. 483-490 (1998)
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[2] Keck spectroscopy of three gravitational lens systems discovered in the JVAS and CLASS surveys, C. D. Fassnacht and J. G. Cohen, Astron. J. vol. 115, p. 377 (1998)
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[3] NICMOS images of JVAS/CLASS gravitational lens systems, N. Jackson et al., Mon. Not. R. Astron. Soc. 311, pp. 389-396 (2000)
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[4] The Gravitational Lens-Galaxy Group Connection. I. Discovery of a Group Coincident with CLASS B0712+472, C. D. Fassnacht and L. M. Lubin, Astron. J. 123, iss. 2, pp. 627-636 (2002)
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[5] A submillimeter survey of gravitationally lensed quasars, R. Barvainis and R. Ivison, Astrophys. J. 571, pp. 712-720 (2002)
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