2003ApJ...598..138K


C.D.S. - SIMBAD4 rel 1.7 - 2021.06.14CEST09:59:23

2003ApJ...598..138K - Astrophys. J., 598, 138-161 (2003/November-3)

Identifying lenses with small-scale structure. I. Cusp lenses.

KEETON C.R., GAUDI B.S. and PETTERS A.O.

Abstract (from CDS):

The inability of standard models to explain the flux ratios in many four-image gravitational lens systems has been presented as evidence for significant small-scale structure in lens galaxies. That claim has generally relied on detailed lens modeling, so it is both model dependent and somewhat difficult to interpret. We present a more robust and generic method for identifying lenses with small-scale structure. For a close triplet of images created when the source lies near an ideal cusp catastrophe, the sum of the signed magnifications should exactly vanish, independent of any global properties of the lens potential. For realistic cusps, the magnification sum vanishes only approximately, but we show that it is possible to place strong upper bounds on the degree to which the magnification sum can deviate from zero. Lenses with flux ratio ``anomalies'', or fluxes that significantly violate the upper bounds, can be said with high confidence to have structure in the lens potential on scales of the image separation or smaller. Five observed lenses have such flux ratio anomalies: B2045+265 has a strong anomaly at both radio and optical/near-IR wavelengths; B0712+472 has a strong anomaly at optical/near-IR wavelengths and a marginal anomaly at radio wavelengths; 1RXS J1131-1231 has a strong anomaly at optical wavelengths; RX J0911+0551 appears to have an anomaly at optical/near-IR wavelengths, although the conclusion in this particular lens is subject to uncertainties in the typical strength of octopole density perturbations in early-type galaxies; and finally, SDSS J0924+0219 has a strong anomaly at optical wavelengths. Interestingly, analysis of the cusp relation does not reveal a significant anomaly in B1422+231, even though this lens is known to be anomalous from detailed modeling.
Method. that are more sophisticated (and less generic) than the cusp relation may therefore be necessary to uncover flux ratio anomalies in some systems. Although these flux ratio anomalies might represent either millilensing or microlensing, we cannot identify the cause of the anomalies using only broadband flux ratios in individual lenses. Rather, the conclusion we can draw is that the lenses have significant structure in the lens potential on scales comparable to or smaller than the separation between the images. Additional arguments must be invoked to specify the nature of this small-scale structure.

Abstract Copyright:

Journal keyword(s): Cosmology: Theory - Cosmology: Dark Matter - Galaxies: Formation - Cosmology: Gravitational Lensing - Cosmology: Large-Scale Structure of Universe

Simbad objects: 23

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Number of rows : 23

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2021
#notes
1 CLASS B0128+437 Rad 01 31 +44.0           ~ 55 0
2 QSO B0132-097 QSO 01 34 35.6616718 -09 31 03.004141   24.52 22.70 20.80   ~ 100 1
3 4C 05.19 QSO 04 14 37.7673624 +05 34 42.328449   24.100 23.800 21.270   ~ 337 2
4 [VV2006] J043814.8-122314 QSO 04 38 14.88 -12 17 14.6     17.15     ~ 189 2
5 QSO B0712+472 QSO 07 16 03.65 +47 08 50.6     23.0     ~ 105 1
6 QSO B0908+0603 QSO 09 11 27.6052 +05 50 54.281   18.44 18.16     ~ 215 2
7 QSO J0924+0219 QSO 09 24 55.8048 +02 19 24.850   18.58 18.36     ~ 113 1
8 QSO B1115+080A QSO 11 18 16.951 +07 45 58.23   16.61 16.44     ~ 639 2
9 QSO J1131-1231 QSO 11 31 51.5387 -12 31 58.716           ~ 231 1
10 [RGO99] HST J12531-2914 G 12 53 06.70 -29 14 30.0           ~ 24 0
11 QSO B1359+154 QSO 14 01 35.588 +15 13 24.15     21.90     ~ 69 1
12 [WZA2016] hst14113 10 212.83200+52.19163 GiC 14 11 19.68 +52 11 29.9   23.00   21.13   ~ 18 1
13 QSO J1415+1129 QSO 14 15 46.25 +11 29 43.4   17.63 17.23     ~ 607 0
14 EGSIRAC J141735.72+522646.0 G 14 17 35.72443 +52 26 46.0560   24.04 21.53 21.38 19.971 ~ 59 1
15 [MMN2007] A1 gLS 14 17 35.9 +52 26 46     21.53   19.69 ~ 78 0
16 QSO B1422+2309 BLL 14 24 38.09400 +22 56 00.5900   16.77 15.84 14.79   ~ 424 1
17 [PBW92] 1422+231 gLS 14 24 38.09400 +22 56 00.5900   16.77 15.84 14.79   ~ 355 0
18 CLASS B1555+375 LeQ 15 57 11.884 +37 21 35.80           ~ 43 0
19 NVSS J160914+653229 rG 16 09 13.96 +65 32 28.8     19.4     ~ 193 1
20 CLASS B1933+503 Rad 19 34 31.02 +50 25 23.5           ~ 82 1
21 [VV2000] J204719.3+264340 QSO 20 47 20.3 +26 44 03     20.60     ~ 107 2
22 QSO J2240+0321 QSO 22 40 30.234 +03 21 30.63           ~ 650 0
23 Z 378-15 G 22 40 30.23447 +03 21 30.6290           ~ 629 0

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2021.06.14-09:59:23

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