TY - JOUR AU - Glazebrook, K AB - ABSTRACTStringent observational constraints on the subgalactic matter power spectrum would allow one to distinguish between the concordance ΛCDM and the various alternative dark-matter models that predict significantly different properties of mass structure in galactic haloes. Galaxy–galaxy strong gravitational lensing provides a unique opportunity to probe the subgalactic mass structure in lens galaxies beyond the Local Group. Here, we demonstrate the first application of a novel methodology to observationally constrain the subgalactic matter power spectrum in the inner regions of massive elliptical lens galaxies on 1–10 kpc scales from the power spectrum of surface-brightness anomalies in highly magnified galaxy-scale Einstein rings and gravitational arcs. The pilot application of our approach to Hubble Space Telescope (HST/WFC3/F390W) observations of the SLACS lens system SDSS J0252+0039 allows us to place the following observational constraints (at the 99 per cent confidence level) on the dimensionless convergence power spectrum $\Delta ^{2}_{\delta \kappa }$ and the standard deviation in the aperture mass σAM: $\Delta ^{2}_{\delta \kappa }\lt 1$ (σAM < 0.8 × 108 M⊙) on 0.5-kpc scale, $\Delta ^{2}_{\delta \kappa }\lt 0.1$ (σAM < 1 × 108 M⊙) on 1-kpc scale and $\Delta ^{2}_{\delta \kappa }\lt 0.01$ (σAM < 3 × 108 M⊙) on 3-kpc scale. These first upper-limit constraints still considerably exceed the estimated effect of CDM subhaloes. However, future analysis of a larger sample of galaxy–galaxy strong lens systems can substantially narrow down these limits and possibly rule out dark-matter models that predict a significantly higher level of density fluctuations on the critical subgalactic scales. TI - Probing sub-galactic mass structure with the power spectrum of surface-brightness anomalies in high-resolution observations of galaxy–galaxy strong gravitational lenses. II. Observational constraints on the subgalactic matter power spectrum JF - Monthly Notices of the Royal Astronomical Society DO - 10.1093/mnras/stad1402 DA - 2023-05-11 UR - https://www.deepdyve.com/lp/oxford-university-press/probing-sub-galactic-mass-structure-with-the-power-spectrum-of-surface-Chinsqrez7 SP - 1310 EP - 1325 VL - 523 IS - 1 DP - DeepDyve ER -