Work

SDSS J1001+5027: Strong microlensing-induced chromatic variation caught in the act

Year: 2025

Type: article

Abstract: We conducted long-term monitoring of the doubly imaged gravitationally lensed quasar SDSS J1001+5027 consisting of spectro-photometric observations separated by ∼120 days (time delay between both quasar images), as well as test and auxiliary data. This monitoring approach allowed us to reliably find a strong microlensing-induced chromatic variation of the quasar continuum in the period 2022–2025. The ongoing microlensing event has caused the delay-corrected spectral flux ratio in 2025 to have a dramatic changing look, opening the door to very promising observations of the system in the coming years. These future follow-up observations of such a rare event are expected to provide critical information to discuss, among other things, the structure of the inner accretion flow towards the central supermassive black hole in SDSS J1001+5027.

Source: Astronomy and Astrophysics

DOI: 10.1051/0004-6361/202556521

Authors: Luis J. Goicoechea, Vyacheslav N. Shalyapin

Institutions: Universidad de Cantabria, Consejo Superior de Investigaciones Científicas, Instituto de Física de Cantabria, National Academy of Sciences of Ukraine, O.Ya. Usikov Institute for Radiophysics and Electronics

Language: English

Topic: Astrophysical Phenomena and Observations

Subfield: Astronomy and Astrophysics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $1,865