Discovery of extreme quasi-periodic eruptions in a newly accreting massive black hole

We acknowledge funding from ANID programmes: Millennium Science Initiative Program NCN2023_002 (L.H.-G., J. Cuadra, P.A., S.B., M.L.M.-A.), Millennium Science Initiative, AIM23-0001 (L.H.-G., F.E.B., M.L.M.-A.), ANID-Chile BASAL CATA FB210003 (R.J.A., F.E.B., C.R.), FONDECYT Iniciación 11241477 (L.H.-G.), FONDECYT Regular 1211429 (J. Cuadra), FONDECYT Regular 1241422 (P.A., B.S.), FONDECYT Regular 1231718 (R.J.A.), FONDECYT Regular 1241005 (F.E.B.), Fondecyt Regular 1230345 (C.R.) and Programa de Becas/Doctorado Nacional 21212344 (S.B.). C.R. acknowledges support from the China–Chile joint research fund. A.B. acknowledges support from the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany’s Excellence Strategy—EXC 2094-390783311. K.E.S.F. and B.M. are supported by NSF AST-1831415, NSF AST-2206096 and Simons Foundation grant 533845. R.A. was supported by NASA through the NASA Hubble Fellowship grant HST-HF2-51499.001-A awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Incorporated, under NASA contract NAS5-26555. A.G. is grateful for support from the Forrest Research Foundation. D.H. is supported by DLR grant FZK 50 OR 2406. M.K. acknowledges support from DLR grant FKZ 50 OR 2307. We acknowledge the use of public data from the Swift data archive through ToO proposals. This work made use of data supplied by the UK Swift Science Data Centre at the University of Leicester. This research has made use of data obtained from the Chandra Data Archive provided by the Chandra X-ray Center (CXC). This work is supported by NASA through the NICER mission and the Astrophysics Explorers Program and uses data and software provided by the High Energy Astrophysics Science Archive Research Center, which is a service of the Astrophysics Science Division at NASA/GSFC and High Energy Astrophysics Division of the Smithsonian Astrophysical Observatory. The scientific results reported in this work are based on observations obtained with XMM-Newton, an ESA science mission with instruments and contributions directly funded by ESA Member States and NASA. This work is based on data from eROSITA, the soft X-ray instrument aboard SRG, a joint Russian–German science mission supported by the Russian Space Agency (Roskosmos), in the interests of the Russian Academy of Sciences represented by its Space Research Institute (IKI), and the Deutsches Zentrum für Luft- und Raumfahrt (DLR). The SRG spacecraft was built by Lavochkin Association (NPOL) and its subcontractors, and is operated by NPOL with support from the Max Planck Institute for Extraterrestrial Physics (MPE). The development and construction of the eROSITA X-ray instrument was led by MPE, with contributions from the Dr. Karl Remeis Observatory Bamberg and ECAP (FAU Erlangen-Nuernberg), the University of Hamburg Observatory, the Leibniz Institute for Astrophysics Potsdam (AIP) and the Institute for Astronomy and Astrophysics of the University of Tübingen, with the support of DLR and the Max Planck Society. The Argelander Institute for Astronomy of the University of Bonn and the Ludwig Maximilians Universität Munich also participated in the science preparation for eROSITA. Part of this work is based on observations obtained with the Samuel Oschin Telescope 48-in. and the 60-in. Telescope at the Palomar Observatory as part of the Zwicky Transient Facility project. ZTF is supported by the National Science Foundation under grant AST-2034437 and a collaboration including Caltech, IPAC, the Weizmann Institute for Science, the Oskar Klein Center at Stockholm University, the University of Maryland, Deutsches Elektronen-Synchrotron and Humboldt University, the TANGO Consortium of Taiwan, the University of Wisconsin at Milwaukee, Trinity College Dublin, Lawrence Livermore National Laboratories and IN2P3, France. Operations are conducted by COO, IPAC and UW. The Australia Telescope Compact Array is part of the Australia Telescope National Facility, which is funded by the Australian Government for operation as a National Facility managed by CSIRO. We thank the staff of the GMRT that made these observations possible. GMRT is run by the National Centre for Radio Astrophysics of the Tata Institute of Fundamental Research. This scientific work uses data obtained from Inyarrimanha Ilgari Bundara/the Murchison Radio-astronomy Observatory. We acknowledge the Wajarri Yamaji People as the Traditional Owners and native title holders of the observatory site. CSIRO’s ASKAP radio telescope is part of the Australia Telescope National Facility (https://ror.org/05qajvd42). Operation of ASKAP is funded by the Australian Government with support from the National Collaborative Research Infrastructure Strategy. ASKAP uses the resources of the Pawsey Supercomputing Research Centre. Establishment of ASKAP, Inyarrimanha Ilgari Bundara, the CSIRO Murchison Radio-astronomy Observatory and the Pawsey Supercomputing Research Centre are initiatives of the Australian Government, with support from the Government of Western Australia and the Science and Industry Endowment Fund. This paper includes archived data obtained through the CSIRO ASKAP Science Data Archive, CASDA. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. CIRADA is funded by a grant from the Canada Foundation for Innovation 2017 Innovation Fund (project 35999), as well as by the Provinces of Ontario, British Columbia, Alberta, Manitoba and Quebec. Part of this work was carried out using the Web Interface from the ALeRCE broker.

The datasets generated during and/or analysed during the current study are available from the corresponding author on reasonable request. With the exception of eROSITA proprietary data, the raw data of the X-ray satellites are available from public archives. In this work we used the following X-ray observations: Swift ObsIDs 00014350001-00014350039, Chandra obsID 29355, NICER ObsIDs 7204490101–7204490160 and XMM-Newton ObsIDs 0935191401–0935191601.