ABSTRACT In this work, we examine the application of the wavelet transform to the X-ray timing analyses of active galactic nuclei (AGN) and quasi-periodic eruption sources (QPEs). Several scenarios are simulated to test the effectiveness of the wavelet analysis to stationary and non-stationary data. We find that the power spectral density (PSD) slope and the nature of the periodic signal can influence the ability to identify important features in the wavelet power spectrum. In general, weak and transient features can be discerned, which make the wavelet spectrum an important tool in examining AGN light curves. We carried out a wavelet analysis to four unique objects: Ark 120, IRAS 13224-3809, RE J1034+396, and the QPE GSN 069. The well-known quasi-periodic oscillation (QPO) in RE J1034 + 396 is significantly detected in the wavelet power spectrum. In IRAS 13224-3809, significant transient features appear during a flare at frequencies coincident with previously detected reverberation signals. Finally, the wavelet power spectrum of the QPE GSN 069 significantly reveals four persistent signals that exhibit a 3:2 ratio in oscillation frequencies, consistent with high-frequency QPOs in stellar mass X-ray binaries, but we cannot rule out the possibility this is an artefact of the calculation.

More from our Archive

• DOI: 10.1093/mnras/stad1984 2023

  Analysing the large-scale bulk flow using cosmicflows4: increasing tension with the standard cosmological model

  Richard Watkins, Trey Allen, Collin James Bradford, Albert Ramon, Alexandra Walker, Hume A Feldman, Rachel Cionitti, Yara Al-Shorman, Ehsan Kourkchi, R Brent Tully

• DOI: 10.1093/mnras/stad2032 2023

  <i>JWST</i> early Universe observations and ΛCDM cosmology

  Rajendra P Gupta

• DOI: 10.1093/mnras/stad2046 2023

  Feedback reshapes the baryon distribution within haloes, in halo outskirts, and beyond: the closure radius from dwarfs to massive clusters

  Mohammadreza Ayromlou, Dylan Nelson, Annalisa Pillepich

• DOI: 10.1029/2022je007612 2023

  Mineralogy, Morphology, and Emplacement History of the Maaz Formation on the Jezero Crater Floor From Orbital and Rover Observations

  Briony Horgan, Arya Udry, Melissa Rice, Sanna Alwmark, Hans E. F. Amundsen, James F. Bell, Larry Crumpler, Brad Garczynski, Jeff Johnson, Kjartan Kinch, Lucia Mandon, Marco Merusi, Chase Million, Jorge I. Núñez, Patrick Russell, Justin I. Simon, Michael St. Clair, Kathryn M. Stack, Alicia Vaughan, Brittan Wogsland, Andrew Annex, Andreas Bechtold, Tor Berger, Olivier Beyssac, Adrian Brown, Ed Cloutis, Barbara A. Cohen, Sarah Fagents, Linda Kah, Ken Farley, David Flannery, Sanjeev Gupta, Svein‐Erik Hamran, Yang Liu, Gerhard Paar, Cathy Quantin‐Nataf, Nicolas Randazzo, Eleni Ravanis, Steven Sholes, David Shuster, Vivian Sun, Christian Tate, Nick Tosca, Meenakshi Wadhwa, Roger C. Wiens

• DOI: 10.1093/mnras/stad2013 2023

  The Dark Energy Survey Year 3 and eBOSS: constraining galaxy intrinsic alignments across luminosity and colour space

  S Samuroff, R Mandelbaum, J Blazek, A Campos, N MacCrann, G Zacharegkas, A Amon, J Prat, S Singh, J Elvin-Poole, A J Ross, A Alarcon, E Baxter, K Bechtol, M R Becker, G M Bernstein, A Carnero Rosell, M Carrasco Kind, R Cawthon, C Chang, R Chen, A Choi, M Crocce, C Davis, J DeRose, S Dodelson, C Doux, A Drlica-Wagner, K Eckert, S Everett, A Ferté, M Gatti, G Giannini, D Gruen, R A Gruendl, I Harrison, K Herner, E M Huff, M Jarvis, N Kuropatkin, P-F Leget, P Lemos, J McCullough, J Myles, A Navarro-Alsina, S Pandey, A Porredon, M Raveri, M Rodriguez-Monroy, R P Rollins, A Roodman, G Rossi, E S Rykoff, C Sánchez, L F Secco, I Sevilla-Noarbe, E Sheldon, T Shin, M A Troxel, I Tutusaus, N Weaverdyck, B Yanny, B Yin, Y Zhang, J Zuntz, M Aguena, O Alves, J Annis, D Bacon, E Bertin, S Bocquet, D Brooks, D L Burke, J Carretero, M Costanzi, L N da Costa, M E S Pereira, J De Vicente, S Desai, H T Diehl, J P Dietrich, P Doel, I Ferrero, B Flaugher, J Frieman, J García-Bellido, S R Hinton, D L Hollowood, K Honscheid, D J James, K Kuehn, O Lahav, J L Marshall, P Melchior, J Mena-Fernández, F Menanteau, R Miquel, J Newman, A Palmese, A Pieres, A A Plazas Malagón, E Sanchez, V Scarpine, M Smith, E Suchyta, M E C Swanson, G Tarle, C To,

• DOI: 10.3390/life13071472 2023

  Exploring the Frontiers of Neuroimaging: A Review of Recent Advances in Understanding Brain Functioning and Disorders

  Chiahui Yen, Chia-Li Lin, Ming-Chang Chiang

• DOI: 10.1093/mnras/stad2101 2023

  Jellyfish galaxies with the IllustrisTNG simulations – when, where, and for how long does ram pressure stripping of cold gas occur?

  Eric Rohr, Annalisa Pillepich, Dylan Nelson, Elad Zinger, Gandhali D Joshi, Mohammadreza Ayromlou

• DOI: 10.1093/mnras/stad2087 2023

  MUSE Analysis of Gas around Galaxies (MAGG) – V. Linking ionized gas traced by C <scp>iv</scp> and Si <scp>iv</scp> absorbers to Ly α emitting galaxies at <i>z</i> ≈ 3.0–4.5

  Marta Galbiati, Michele Fumagalli, Matteo Fossati, Emma K Lofthouse, Rajeshwari Dutta, J Xavier Prochaska, Michael T Murphy, Sebastiano Cantalupo

• DOI: 10.1093/mnras/stad2001 2023

  Identifying the SN 2022acko progenitor with <i>JWST</i>

  Schuyler D Van Dyk, K Azalee Bostroem, WeiKang Zheng, Thomas G Brink, Ori D Fox, Jennifer E Andrews, Alexei V Filippenko, Yize Dong, Emily Hoang, Griffin Hosseinzadeh, Daryl Janzen, Jacob E Jencson, Michael J Lundquist, Nicolas Meza, Dan Milisavljevic, Jeniveve Pearson, David J Sand, Manisha Shrestha, Stefano Valenti, D Andrew Howell

• DOI: 10.1093/mnras/stad2031 2023

  The halo mass function and filaments in full cosmological simulations with fuzzy dark matter

  Simon May, Volker Springel