Browsing by Author "Finlez, Carolina"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    BASS XLIV. Morphological preferences of local hard X-ray selected AGNs
    (EDP Sciences, 2025) Parra Tello, Miguel Agustín; Bauer, Franz E.; Cicco, Demetra de; Doll, Goran; Koss, Michael; Treister, Ezequiel; Finlez, Carolina; Troncoso Balbiano, Marco Javier; Auge, Connor; Moral Castro, Ignacio del; Chung, Aeree; Gupta, Kriti K.; Kim, Jeein; Oh, Kyuseok; Ricci, Claudio; Ricci, Federica; Rojas, Alejandra; Caglar, Turgay; Harrison, Fiona; Powell, Meredith C.; Stern, Daniel; Trakhtenbrot, Benny; Urry, C. Megan
    We present detailed morphological classifications for the hosts of 1189 hard X-ray selected (14–195 keV) active galactic nuclei (AGNs) from the Swift-BAT 105-month catalog as part of the BAT AGN Spectroscopic Survey (BASS). BASS provides a powerful all-sky census of nearby AGNs, minimizing obscuration biases and providing a robust dataset for studying AGN-host galaxy connections. Classifications are based on a volunteer-based visual inspection workflow on the Zooniverse platform, adapted from the Galaxy Zoo DECaLS (GZD) project. Dual-contrast grz color composite images, generated from public surveys (e.g., NOAO Legacy Survey, Pan-STARRS, SDSS) and dedicated observations enabled key morphological features to be identified. Our analysis reveals that, with respect to a control sample of inactive galaxies, BASS AGN hosts show a deficiency of smooth elliptical galaxies (∼70%) and spiral galaxies with prominent arms (∼80%), while displaying an excess of mergers or disturbed systems (∼400%), and disk galaxies without a spiral structure (∼300%). These trends are found after controlling for redshift and i-band magnitude, which suggests a preference for AGN activity in gas-rich, dynamically disturbed environments or transitional disk systems. We also find a higher bar fraction among AGN hosts than in a control sample (∼50% vs. ∼30%). We further explore the relationships between AGN properties (e.g., X-ray luminosity, black hole mass, and Eddington ratio) and host morphology, and find that high-luminosity and high-accretion AGNs preferentially reside in smooth or point-like hosts. At the same time, lower-luminosity AGNs are more common in disk galaxies. These results underscore the importance of morphological studies in understanding the fueling and feedback mechanisms that drive AGN activity and their role in galaxy evolution. Our dataset provides a valuable benchmark for future multiwavelength surveys (e.g. LSST, Roman, and Euclid) and automated morphological classification efforts.
  • Thumbnail Image
    Item
    Signatures of feedback in the spectacular extended emission region of NGC 5972
    (2023) 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.; Urry, Megan
    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 Lbol 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 Pkin/Lbol ∼ 0.8 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.