The QPO in RE J1034+396 Originates in the Hot Corona
RE J1034+396 is one of the few active galactic nuclei (AGNs) with a significant quasiperiodic oscillation (QPO). The QPO has been observed in over 1 Ms of XMM-Newton observations spanning over a decade. We investigate the power spectral density function (PSD) of seven long (∼90 ks) XMM-Newton observ...
Saved in:
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
IOP Publishing
2025-01-01
|
| Series: | The Astrophysical Journal |
| Subjects: | |
| Online Access: | https://doi.org/10.3847/1538-4357/ade23d |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1849422342118178816 |
|---|---|
| author | Chloe S. Taylor Dan R. Wilkins Steven W. Allen |
| author_facet | Chloe S. Taylor Dan R. Wilkins Steven W. Allen |
| author_sort | Chloe S. Taylor |
| collection | DOAJ |
| description | RE J1034+396 is one of the few active galactic nuclei (AGNs) with a significant quasiperiodic oscillation (QPO). The QPO has been observed in over 1 Ms of XMM-Newton observations spanning over a decade. We investigate the power spectral density function (PSD) of seven long (∼90 ks) XMM-Newton observations of the AGN RE J1034+396 in two energy bands. The soft (0.3–0.5 keV) band targets emission from the disk, while the hard (2–7 keV) band isolates the primary X-ray continuum emission from the corona. The QPO is significantly detected in the hard band of five of the seven observations. The best-fitting models indicate that the QPO detection in both bands is entirely attributable to the coronal emission with no additional contribution from the disk. This explains the strong coherence between the hard and soft bands at the QPO frequency. The covariance spectrum is consistent with this picture as the variability at QPO frequencies is attributed solely to fluctuations in the hot corona. The time lag as a function of energy is well described by a ∼2000 s intrinsic soft lag, resulting from the disk responding to emission from the corona, that undergoes phase wrapping at approximately the QPO frequency. By demonstrating that in this system the QPO arises in the corona, we provide new insights into the mechanisms generating QPOs. |
| format | Article |
| id | doaj-art-1716b13dffcd4cbf976368c241ee202f |
| institution | Kabale University |
| issn | 1538-4357 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj-art-1716b13dffcd4cbf976368c241ee202f2025-08-20T03:31:07ZengIOP PublishingThe Astrophysical Journal1538-43572025-01-01987213510.3847/1538-4357/ade23dThe QPO in RE J1034+396 Originates in the Hot CoronaChloe S. Taylor0https://orcid.org/0000-0003-3117-3476Dan R. Wilkins1https://orcid.org/0000-0002-4794-5998Steven W. Allen2https://orcid.org/0000-0003-0667-5941Department of Physics, Stanford University , 382 Via Pueblo Mall, Stanford, CA 94305, USA ; ctaylor9@stanford.edu, swa@stanford.edu; Kavli Institute for Particle Astrophysics & Cosmology, Stanford University , 452 Lomita Mall, Stanford, CA 94305, USA ; dan.wilkins@stanford.eduKavli Institute for Particle Astrophysics & Cosmology, Stanford University , 452 Lomita Mall, Stanford, CA 94305, USA ; dan.wilkins@stanford.eduDepartment of Physics, Stanford University , 382 Via Pueblo Mall, Stanford, CA 94305, USA ; ctaylor9@stanford.edu, swa@stanford.edu; Kavli Institute for Particle Astrophysics & Cosmology, Stanford University , 452 Lomita Mall, Stanford, CA 94305, USA ; dan.wilkins@stanford.edu; SLAC National Accelerator Laboratory , 2575 Sand Hill Road, Menlo Park, CA 94025, USARE J1034+396 is one of the few active galactic nuclei (AGNs) with a significant quasiperiodic oscillation (QPO). The QPO has been observed in over 1 Ms of XMM-Newton observations spanning over a decade. We investigate the power spectral density function (PSD) of seven long (∼90 ks) XMM-Newton observations of the AGN RE J1034+396 in two energy bands. The soft (0.3–0.5 keV) band targets emission from the disk, while the hard (2–7 keV) band isolates the primary X-ray continuum emission from the corona. The QPO is significantly detected in the hard band of five of the seven observations. The best-fitting models indicate that the QPO detection in both bands is entirely attributable to the coronal emission with no additional contribution from the disk. This explains the strong coherence between the hard and soft bands at the QPO frequency. The covariance spectrum is consistent with this picture as the variability at QPO frequencies is attributed solely to fluctuations in the hot corona. The time lag as a function of energy is well described by a ∼2000 s intrinsic soft lag, resulting from the disk responding to emission from the corona, that undergoes phase wrapping at approximately the QPO frequency. By demonstrating that in this system the QPO arises in the corona, we provide new insights into the mechanisms generating QPOs.https://doi.org/10.3847/1538-4357/ade23dActive galactic nuclei |
| spellingShingle | Chloe S. Taylor Dan R. Wilkins Steven W. Allen The QPO in RE J1034+396 Originates in the Hot Corona The Astrophysical Journal Active galactic nuclei |
| title | The QPO in RE J1034+396 Originates in the Hot Corona |
| title_full | The QPO in RE J1034+396 Originates in the Hot Corona |
| title_fullStr | The QPO in RE J1034+396 Originates in the Hot Corona |
| title_full_unstemmed | The QPO in RE J1034+396 Originates in the Hot Corona |
| title_short | The QPO in RE J1034+396 Originates in the Hot Corona |
| title_sort | qpo in re j1034 396 originates in the hot corona |
| topic | Active galactic nuclei |
| url | https://doi.org/10.3847/1538-4357/ade23d |
| work_keys_str_mv | AT chloestaylor theqpoinrej1034396originatesinthehotcorona AT danrwilkins theqpoinrej1034396originatesinthehotcorona AT stevenwallen theqpoinrej1034396originatesinthehotcorona AT chloestaylor qpoinrej1034396originatesinthehotcorona AT danrwilkins qpoinrej1034396originatesinthehotcorona AT stevenwallen qpoinrej1034396originatesinthehotcorona |