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Constraints on the inner regions of lensing galaxies from central images using a recent AGN offset distribution
- Source :
- Monthly Notices of the Royal Astronomical Society. 522:1863-1880
- Publication Year :
- 2023
- Publisher :
- Oxford University Press (OUP), 2023.
-
Abstract
- In gravitational lensing, central images in quads can serve as a powerful probe of the inner regions of lens galaxies. The presence of an offset central supermassive black hole (SMBH) has the potential to distort the time-delay surface in a way such that 3 central images form: a strongly de-magnified image near the SMBH, and two less de-magnified (and potentially observable) images at a central maximum and saddle point. Using a quad lens macro model, we simulate the constraints that could be placed on various lens galaxy parameters based on their central images probability of detection or non-detection. Informed by a recent low-redshift distribution of off-nucleus AGN, we utilize Bayesian inference to constrain the mean SMBH off-nucleus distance and galactic core radius for a sample of 6 quads. In general, we find that a detection of the central image in any quad would favor larger SMBH off-nucleus distances and galaxy core sizes. Assuming a linear relationship between core radii and velocity dispersion $r_c = b\sigma$, these results similarly imply strong constraints on $b$, where the likely case of a central image non-detection in each quad constraining $b$ to $3.11^{+2.72}_{-2.26} \times 10^{-4}$ kpc km$^{-1}$ s. Our results show that tight constraints on lens galaxy parameters can be made regardless of a detection or non-detection of a central image. Therefore, we recommend observational searches for the central image, possibly using our suggested novel detection technique in UV filters, to formalize stronger constraints on lens galaxy parameters.<br />Comment: MNRAS, Accepted, 20 pages, 15 figures
Details
- ISSN :
- 13652966 and 00358711
- Volume :
- 522
- Database :
- OpenAIRE
- Journal :
- Monthly Notices of the Royal Astronomical Society
- Accession number :
- edsair.doi.dedup.....e2f5498490f8e9e861bb2f21a37122f1
- Full Text :
- https://doi.org/10.1093/mnras/stad1110