1. Signatures of feedback in the spectacular extended emission region of NGC 5972.
- Author
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Harvey, Thomas, Maksym, W Peter, Keel, William, Koss, Michael, Bennert, Vardha N, Chojnowski, S Drew, Treister, Ezequiel, Finlez, Carolina, Lintott, Chris J, Moiseev, Alexei, Simmons, Brooke D, Sartori, Lia F, and Urry, Megan
- Subjects
SUPERMASSIVE black holes ,ACTIVE galactic nuclei ,SOFT X rays ,SPACE telescopes ,ACTIVE galaxies - Abstract
We present Chandra X-ray Observatory observations and Space Telescope Imaging Spectrograph spectra of NGC 5972, one of the 19 'Voorwerpjes' galaxies. This galaxy contains an extended emission-line region (EELR) and an arcsecond scale nuclear bubble. NGC 5972 is a faded active galactic nucleus (AGN), with EELR luminosity suggesting a 2.1 dex decrease in L
bol in the last ∼5 × 104 yr. We investigate the role of AGN feedback in exciting the EELR and bubble given the long-term variability and potential accretion state changes. We detect broad-band (0.3–8 keV) X-ray emission in the near-nuclear regions, coincident with the [O iii ] bubble, as well as diffuse soft X-ray emission coincident with the EELR. The soft nuclear (0.5–1.5 keV) emission is spatially extended and the spectra are consistent with two apec thermal populations (∼0.80 and ∼0.10 keV). We find a bubble age >2.2 Myr, suggesting formation before the current variability. We find evidence for efficient feedback with |$P_{\textrm {kin}}/L_{\textrm {bol}}\sim 0.8~{{\ \rm per\ cent}}$| , which may be overestimated given the recent Lbol variation. [O iii ] kinematics show a 300 km s−1 high-ionization velocity consistent with disturbed rotation or potentially the line-of-sight component of a ∼780 km s−1 thermal X-ray outflow capable of driving strong shocks to photoionize the precursor material. We explore possibilities to explain the overall jet, radio lobe and EELR misalignment including evidence for a double supermassive black hole which could support a complex misaligned system. [ABSTRACT FROM AUTHOR]- Published
- 2023
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