Constraints on the inner regions of lensing galaxies from central images using a recent AGN offset distribution
| Autor: | D Perera, L L R Williams, C Scarlata |
|---|---|
| Rok vydání: | 2023 |
| Předmět: | |
| Zdroj: | Monthly Notices of the Royal Astronomical Society. 522:1863-1880 |
| ISSN: | 1365-2966 0035-8711 |
| DOI: | 10.1093/mnras/stad1110 |
| Popis: | 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. Comment: MNRAS, Accepted, 20 pages, 15 figures |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|