Browsing by Author "Harrison, F."

Now showing 1 - 20 of 23
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    A New Compton-thick AGN in Our Cosmic Backyard: Unveiling the Buried Nucleus in NGC 1448 with NuSTAR
    (2017) Annuar, A.; Alexander, D.; Gandhi, P.; Lansbury, G.; Asmus, D.; Ballantyne, D.; Bauer, Franz Erik; Boggs, S.; Boorman, P.; Brandt W.; Brightman, M.|Christensen, F.; Craig, W.; Farrah, D.; Goulding, A.; Hailey, C.; Harrison, F.; Koss, M.; Lamassa, S.; Murray, S.; Ricci, Claudio; Rosario, D.; Stanley, F.; Stern, D.; Zhang, W.
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    BASS XXXI: Outflow scaling relations in low redshift X-ray AGN host galaxies with MUSE
    (2022) Kakkad, D.; Sani, E.; Rojas, A. F.; Mallmann, Nicolas D.; Veilleux, S.; Bauer, Franz E.; Ricci, F.; Mushotzky, R.; Koss, M.; Ricci, C.; Treister, E.; Privon, George C.; Nguyen, N.; Bär, R.; Harrison, F.; Oh, K.; Powell, M.; Riffel, R.; Stern, D.; Trakhtenbrot, B.; Urry, C. M.
    Ionized gas kinematics provide crucial evidence of the impact that active galactic nuclei (AGNs) have in regulating star formation in their host galaxies. Although the presence of outflows in AGN host galaxies has been firmly established, the calculation of outflow properties such as mass outflow rates and kinetic energy remains challenging. We present the [O iii]lambda 5007 ionized gas outflow properties of 22 z<0.1 X-ray AGN, derived from the BAT AGN Spectroscopic Survey using MUSE/VLT. With an average spatial resolution of 1 arcsec (0.1-1.2 kpc), the observations resolve the ionized gas clouds down to sub-kiloparsec scales. Resolved maps show that the [O iii] velocity dispersion is, on average, higher in regions ionized by the AGN, compared to star formation. We calculate the instantaneous outflow rates in individual MUSE spaxels by constructing resolved mass outflow rate maps, incorporating variable outflow density and velocity. We compare the instantaneous values with time-averaged outflow rates by placing mock fibres and slits on the MUSE field-of-view, a method often used in the literature. The instantaneous outflow rates (0.2-275 M-circle dot yr(-1)) tend to be two orders of magnitude higher than the time-averaged outflow rates (0.001-40 M-circle dot yr(-1)). The outflow rates correlate with the AGN bolometric luminosity (L-bol similar to 10(42.71)-10(45.62) erg s(-1)) but we find no correlations with black hole mass (10(6.1)-10(8.9) M-circle dot), Eddington ratio (0.002-1.1), and radio luminosity (10(21)-10(26) W Hz(-1)). We find the median coupling between the kinetic energy and L-bol to be 1 per cent, consistent with the theoretical predictions for an AGN-driven outflow.
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    BASS XXXVII: The Role of Radiative Feedback in the Growth and Obscuration Properties of Nearby Supermassive Black Holes
    (2022) Ricci, C.; Ananna, T. T.; Temple, M. J.; Urry, C. M.; Koss, M. J.; Trakhtenbrot, B.; Ueda, Y.; Stern, D.; Bauer, F. E.; Treister, E.; Privon, G. C.; Oh, K.; Paltani, S.; Stalevski, M.; Ho, L. C.; Fabian, A. C.; Mushotzky, R.; Chang, C. S.; Ricci, F.; Kakkad, D.; Sartori, L.; Baer, R.; Caglar, T.; Powell, M.; Harrison, F.
    We study the relation between obscuration and supermassive black hole (SMBH) accretion using a large sample of hard X-ray selected active galactic nuclei (AGNs). We find a strong decrease in the fraction of obscured sources above the Eddington limit for dusty gas (log lambda(Edd) >= -2) confirming earlier results, and consistent with the radiation-regulated unification model. This also explains the difference in the Eddington ratio distribution functions (ERDFs) of type 1 and type 2 AGNs obtained by a recent study. The break in the ERDF of nearby AGNs is at log lambda*(Edd) = -1.34 +/- 0.07. This corresponds to the lambda(Edd) where AGNs transition from having most of their sky covered by obscuring material to being mostly devoid of absorbing material. A similar trend is observed for the luminosity function, which implies that most of the SMBH growth in the local universe happens when the AGN is covered by a large reservoir of gas and dust. These results could be explained with a radiation-regulated growth model, in which AGNs move in the N-H-lambda(Edd) plane during their life cycle. The growth episode starts with the AGN mostly unobscured and accreting at low lambda(Edd). As the SMBH is further fueled, lambda(Edd), N-H and the covering factor increase, leading the AGN to be preferentially observed as obscured. Once lambda(Edd) reaches the Eddington limit for dusty gas, the covering factor and N-H rapidly decrease, leading the AGN to be typically observed as unobscured. As the remaining fuel is depleted, the SMBH goes back into a quiescent phase.
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    BASS. XLII. The Relation between the Covering Factor of Dusty Gas and the Eddington Ratio in Nearby Active Galactic Nuclei
    Ricci, C.; Ichikawa, K.; Stalevski, M.; Kawamuro, T.; Yamada, S.; Ueda, Y.; Mushotzky, R.; Privon, G. C.; Koss, M. J.; Trakhtenbrot, B.; Fabian, A. C.; Ho, L. C.; Asmus, D.; Bauer, Franz Erik; Chang, C. S.; Gupta, K. K.; Oh, K.; Powell, M.; Pfeifle, R. W.; Rojas, A.; Ricci, F.; Temple, M. J.; Toba, Y.; Tortosa, A.; Treister, Ezequiel; Harrison, F.; Stern, D.; Urry, C. M.
    Accreting supermassive black holes (SMBHs) located at the centers of galaxies are typically surrounded by large quantities of gas and dust. The structure and evolution of this circumnuclear material can be studied at different wavelengths, from the submillimeter to the X-ray. Recent X-ray studies have shown that the covering factor of the obscuring material tends to decrease with increasing Eddington ratio, likely due to radiative feedback on dusty gas. Here we study a sample of 549 nearby (z less than or similar to 0.1) hard X-ray (14-195 keV) selected nonblazar active galactic nuclei (AGN) and use the ratio between the AGN infrared and bolometric luminosity as a proxy of the covering factor. We find that, in agreement with what has been found by X-ray studies of the same sample, the covering factor decreases with increasing Eddington ratio. We also confirm previous findings that showed that obscured AGN typically have larger covering factors than unobscured sources. Finally, we find that the median covering factors of AGN located in different regions of the column density-Eddington ratio diagram are in good agreement with what would be expected from a radiation-regulated growth of SMBHs.
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    BASS. XXXIII. Swift-BAT Blazars and Their Jets through Cosmic Time
    (2022) Marcotulli, L.; Ajello, M.; Urry, C. M.; Paliya, V. S.; Koss, M.; Oh, K.; Madejski, G.; Ueda, Y.; Balokovic, M.; Trakhtenbrot, B.; Ricci, F.; Ricci, C.; Stern, D.; Harrison, F.; Powell, M. C.
    We derive the most up-to-date Swift-Burst Alert Telescope (BAT) blazar luminosity function in the 14-195 keV range, making use of a clean sample of 118 blazars detected in the BAT 105 month survey catalog, with newly obtained redshifts from the BAT Active Galatic Nucleus Spectroscopic Survey. We determine the best-fit X-ray luminosity function for the whole blazar population, as well as for flat-spectrum radio quasars (FSRQs) alone. The main results are: (1) at any redshift, BAT detects the most luminous blazars, above any possible break in their luminosity distribution, which means we cannot differentiate between density and luminosity evolution; (2) the whole blazar population, dominated by FSRQs, evolves positively up to redshift z similar to 4.3, confirming earlier results and implying lower number densities of blazars at higher redshifts than previously estimated. The contribution of this source class to the cosmic X-ray background at 14-195 keV can range from 5%-18%, while possibly accounting for 100% of the MeV background. We also derived the average 14 keV-10 GeV spectral energy distribution for BAT blazars, which allows us to predict the number counts of sources in the MeV range, as well as the expected number of high-energy (>100 TeV) neutrinos. A mission like COSI will detect 40 MeV blazars, of which two may have coincident neutrino detections. Finally, taking into account beaming selection effects, the distribution and properties of the parent population of these extragalactic jets are derived. We find that the distribution of viewing angles is quite narrow, with most sources aligned within <5 degrees of the line of sight. Moreover, the average Lorentz factor, Gamma = 8-12, is lower than previously suggested for these powerful sources.
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    BAT AGN Spectroscopic Survey (BASS) – VI. The ΓX–L/LEdd relation.
    (2017) Trakhtenbrot, Benny; Ricci, Claudio; Treister, Ezequiel; Koss, M.; Schawinski, Kevin; Mushotzky, Richard; Ueda, Yoshihiro; Veilleux, Sylvain; Lamperti, Isabella; Oh, Kyuseok; Stern, Daniel; Harrison, F.; Baloković, Mislav; Gehrels, Neil
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    BAT AGN Spectroscopic Survey XXVII: scattered X-Ray radiation in obscured active galactic nuclei
    (2021) Gupta, K. K.; Ricci, C.; Tortosa, A.; Ueda, Y.; Kawamuro, T.; Koss, M.; Trakhtenbrot, B.; Oh, K.; Bauer, F. E.; Ricci, F.; Privon, G. C.; Zappacosta, L.; Stern, D.; Kakkad, D.; Piconcelli, E.; Veilleux, S.; Mushotzky, R.; Caglar, T.; Ichikawa, K.; Elagali, A.; Powell, M. C.; Urry, C. M.; Harrison, F.
    Accreting supermassive black holes (SMBHs), also known as active galactic nuclei (AGN), are generally surrounded by large amounts of gas and dust. This surrounding material reprocesses the primary X-ray emission produced close to the SMBH and gives rise to several components in the broadband X-ray spectra of AGN, including a power-law possibly associated with Thomson-scattered radiation. In this work, we study the properties of this scattered component for a sample of 386 hard-X-ray-selected, nearby (z similar to 0.03) obscured AGN from the 70-month Swift/BAT catalogue. We investigate how the fraction of Thomson-scattered radiation correlates with different physical properties of AGN, such as line-of-sight column density, X-ray luminosity, black hole mass, and Eddington ratio. We find a significant negative correlation between the scattering fraction and the column density. Based on a large number of spectral simulations, we exclude the possibility that this anticorrelation is due to degeneracies between the parameters. The negative correlation also persists when considering different ranges of luminosity, black hole mass, and Eddington ratio. We discuss how this correlation might be either due to the angle dependence of the Thomson cross-section or to more obscured sources having a higher covering factor of the torus. We also find a positive correlation between the scattering fraction and the ratio of [OIII] lambda 5007 to X-ray luminosity. This result is consistent with previous studies and suggests that the Thomson-scattered component is associated with the narrow-line region.
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    BAT AGN spectroscopic survey – XV: the high frequency radio cores of ultra-hard X-ray selected AGN
    (OUP, 2019) Smith, K. L.; Mushotzky, R. F.; Koss, M.; Trakhtenbrot, B.; Ricci, Claudio; Wong, O. I.; Bauer, F. E.; Ricci, F.; Vogel, S.; Stern, D.; Powell, M. C.; Urry, C. M.; Harrison, F.; Mejia-Restrepo, J.; Oh, K.; Baek, J.; Chun, A.
    We have conducted 22 GHz radio imaging at 1 arcsec resolution of 100 low-redshift AGN selected at 14–195 keV by the Swift-BAT. We find a radio core detection fraction of 96 per cent, much higher than lower frequency radio surveys. Of the 96 radio-detected AGN, 55 have compact morphologies, 30 have morphologies consistent with nuclear star formation, and 11 have sub-kpc to kpc-scale jets. We find that the total radio power does not distinguish between nuclear star formation and jets as the origin of the radio emission. For 87 objects, we use optical spectroscopy to test whether AGN physical parameters are distinct between radio morphological types. We find that X-ray luminosities tend to be higher if the 22 GHz morphology is jet-like, but find no significant difference in other physical parameters. We find that the relationship between the X-ray and core radio luminosities is consistent with the LR/LX ∼ 10−5 of coronally active stars. We further find that the canonical fundamental planes of black hole activity systematically overpredict our radio luminosities, particularly for objects with star formation morphologies.
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    Do some AGN lack X-ray emission?
    (2016) Simmonds, C.; Bauer, Franz Erik; Thuan, T.; Izotov, Y.; Stern, D.; Harrison, F.
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    Growing supermassive black holes in the late stages of galaxy mergers are heavily obscured.
    (2017) Ricci, Claudio; Bauer, Franz Erik; Treister, Ezequiel; Privon, G. C.; Schawinski, K.; Blecha, L.; Arevalo, P.; Armus, Lee; Harrison, F.; Ho, L. C.; Iwasawa, K.; Sanders, David B.; Stern, Daniel
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    Hard X-ray emission of the luminous infrared galaxy NGC 6240 as observed by NuSTAR
    (2016) Puccetti, S.; Comastri, A.; Bauer, Franz Erik; Brandt, W.; Fiore, E.; Harrison, F.; Luo, B.; Stern, D.; Urry, C.; Alexander, D.; Annuar, A.; Arevalo, P.; Balokovic, M.; Boggs, S.; Brightman, M.; Craig, W.; Ricci, Claudio
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    NGC 1068: No change in the mid-infrared torus structure despite X-ray variability
    (2017) Lopez-Gonzaga, N.; Asmus, D.; Bauer, Franz Erik; Tristam, K.; Burstcher, L.; Marinucci, A.; Matt, G.; Harrison, F.
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    Nustar and suzaku X-Ray spectroscopy of NGC 4151: evidence for reflection from the inner accretion disk
    (2015) Keck, M.; Brenneman, L.; Ballantyne, D.; Bauer, Franz Erik; Boggs, S.; Christensen, F.; Craig, W.; Dauser, T.; Elvis, M.; Fabian, A.; Fuerst, F.; García, J.; Grefenstette, B.; Hailey, C.; Harrison, F.; Madejski, G.; Marinucci, A.; Matt, G.; Reynolds, C.; Stern, D.; Walton, D.; Zoghbi, A.
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    NuSTAR and XMM-Newton observations of NGC 1365 : Extreme absorption variability and a constant inner accretion disk
    (2014) Walton, D.; Risaliti, G.; Harrison, F.; Fabian, A.; Miller, J.; Arévalo, Patricia; Ballantyne, D.; Boggs, S.
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    NuSTAR catches the unveiling nucleus of NGC 1068
    (2016) Bauer, Franz Erik; Ricci, Claudio; Marinucci, A.; Bianchi, S.; Matt, G.; Alexander, D.; Balokovic, M.; Brandt, W.; Gandhi, P.; Guainazzi, M.; Harrison, F.; Iwasawa, K.; Koss, M.; Madsen, K.; Nicastro, F.; Puccetti, S.; Stern, D.; Walton, D.
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    NuStar observations of the compton-thick active galactic nucleus and ultraluminous X-Ray source candidate in NGC 5643
    (2015) Annuar, A.; Gandhi, P.; Alexander, D.; Lansbury, G.; Arévalo, P.; Ballantyne, D.; Balokovic, M.; Boggs, S.; Brandt, W.; Brightman, M.; Christensen, F.; Craig, W.; Del Moro, A.; Hailey, C.; Harrison, F.; Bauer, Franz Erik
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    The BAT AGN Spectroscopic Survey. XVIII. Searching for Supermassive Black Hole Binaries in X-Rays
    (2020) Liu, T. T.; Koss, M.; Blecha, L.; Ricci, Claudio; Trakhtenbrot, B.; Mushotzky, R.; Harrison, F.; Ichikawa, K.; Kakkad, D.; Treister, Ezequiel; Oh, K.; Powell, M.; Privon, G. C.; Schawinski, K.; Shimizu, T. T.; Smith, K. L.; Stern, D.; Urry, C. M.
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    The Multi-Layer Variable Absorbers in NGC 1365 Revealed by XMM-Newton and NuSTAR
    (2015) Rivers, E.; Risaliti, G.; Walton, D. J.; Harrison, F.; Arévalo, P.; Bauer, Franz Erik; Boggs, S. E.; Brenneman, L. W.; Brightman, M.; Christensen, F. E.
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    The NuSTAR view of nearby compton-thick active galactic nuclei: The cases of NGC 424, NGC 1320, and IC 2560
    (2014) Balokovic, M.; Comastri, A.; Harrison, F.; Alexander, D.; Ballantyne, D.; Bauer, Franz Erik; Boggs, S.; Brandt, W.; Brightman, M.