OJ 287 in a deep X-ray-UV-optical low-state, following the April-June 2020 "super-outburst"
Abstract
We have monitored OJ 287 densely with the Neil Gehrels Swift observatory and the Effelsberg radio telescope since its December 2015 maximum. Before OJ 287 became unobservable due to its solar proximity, it was in outburst reaching the second-brightest X-ray state with Swift (ATel #13658, #13702, #13785; Komossa et al. 2020), characterized by a very soft spectral component and interpreted as "after-flare" in the context of the binary black hole model for OJ 287. Here, we report detection of OJ 287 in a low-state in all bands, when we re-observed it with Swift UVOT and XRT after emerging from sun-constraint on 2020 September 20. On that date, we measured an (0.3-10) keV X-ray countrate of 0.13 cts/s, and UVOT magnitudes in the VEGA system of: UVW2: 15.12+-0.07 (15.07), UVM2: 15.15+/-0.08 (14.91), UVW1: 15.14+/-0.08 (14.97), U: 15.40+/-0.07 (15.27), B: 16.27+/-0.08 (16.16), V: 15.85+/-0.10 (15.77), where values in brackets are corrected for Galactic extinction.
- Publication:
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The Astronomer's Telegram
- Pub Date:
- September 2020
- Bibcode:
- 2020ATel14052....1K
- Keywords:
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- AGN;
- Blazar