Jet Directions in Seyfert Galaxies

By A. L. Kinney, H. Schmitt, Cathie Clarke, J. Pringle, J. Ulvestad, R. Antonucci. 2000

183 citations recorded by the source corpus.

Here we present the study of the relative angle between the accretion disk (or radio jet) and the galaxy disk for a sample of Seyfert galaxies selected from a mostly isotropic property, the 60 μm flux, and warm infrared colors. We used VLA A-array 3.6 cm continuum data and ground-based optical imaging, homogeneously observed and reduced to minimize selection effects. For parts of the analysis we enlarged the sample by including galaxies serendipitously selected from the literature. For each galaxy we have a pair of points (i, δ), which are the inclination of the galaxy relative to the line of sight and the angle between the jet projected into the plane of the sky and the host galaxy major axis, respectively. For some galaxies we also had information about which side of the minor axis is closer to Earth. This data is combined with a statistical technique, developed by us, to determine the distribution of β angles in three dimensions, the angle between the jet and the host galaxy plane axis. We found from an initial analysis of the data of the 60 μm sample, where Seyfert 1 and 2 galaxies were not differentiated, that the observed distribution of i and δ values can be well represented either by a homogeneous sin β distribution in the range 0° ≤ β ≤ 90° or in 0° ≤ β ≤ 65°, but not by an equatorial ring. A more general model, which tested β-distributions in the range β1 ≤ β ≤ β2, for different ranges of β1 and β2 values, required β2 to be larger than 65° and gave preference for β1 smaller than 40°-50°. An important result from our analysis was obtained when we determined whether the jet was projected against the near or the far side of the galaxy and differentiated between Seyfert 1 and Seyfert 2 galaxies, which showed that the model could not represent Seyfert 1 galaxies adequately. We found that the inclusion of viewing angle restrictions for Seyfert 1 galaxies, namely, that a galaxy can be recognized as a Seyfert 1 only if the angle between the jet and the line of sight (|ϕ|) is smaller than a given angle ϕc and that the galaxy inclination i is smaller than an angle ic, gave rise to statistically acceptable models. This indication that there is a difference in viewing angle to the central engine between Seyfert 1 galaxies and Seyfert 2 galaxies is a direct and independent confirmation of the underlying concepts of the unified model. We discuss possible explanations for the misalignment between the accretion disk and the host galaxy disk: warping of the accretion disk by self-irradiation instability, by the Bardeen-Petterson effect, or by a misaligned gravitational potential of a nuclear star cluster surrounding the black hole, as well as feeding of the accretion disk by a misaligned inflow of gas from minor mergers, capture of individual stars or gas from the nuclear star cluster, and the capture of individual molecular clouds from the host galaxy.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/7d88e3337cd4109460280d8ca49c353836ed69c3

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Citations in the corpus

DUST IN THE POLAR REGION AS A MAJOR CONTRIBUTOR TO THE INFRARED EMISSION OF ACTIVE GALACTIC NUCLEI (2013, background): “Radio maps at 3.6 cm and 6 cm show an unresolved point-source, so that no position angle information can be extracted (Morganti et al. 2000; Kinney et al. 2000).”
Determining Inclinations of Active Galactic Nuclei Via Their Narrow-Line Region Kinematics (2012, background): “…between the NLR bicone axis and the normal to the host galaxy disk References: (1) Freeman et al. (1977), (2) Schmitt & Kinney (2000), (3) Kinney et al. (2000), (4) NED, (5) Xilouris & Papadakis (2002), (6) Hicks et al. (2009), (7) Das et al. (2005), (8) Das et al. (2006), (9) Crenshaw…”
Grand unification of AGN activity in the ΛCDM cosmology (2009, background): “King et al. suggest that these accretion episodes are randomly oriented around the BH, an assumption supported by observations indicating that there is no apparent relation between the accretiondisc (or radio jet) orientation and the host galaxy disc (Nagar & Wilson 1999; Kinney et al. 2000).”
A Hubble Space Telescope Survey of Extended [O III] λ5007 Å Emission in a Far-Infrared-Selected Sample of Seyfert Galaxies: Results (2003, methodology): “The information about the radio jet axis was obtained from Kinney et al. (2000).”
Resolving the obscuring torus in NGC 1068 with the power of infrared interferometry: revealing the inner funnel of dust (2009, background): “Although there seems to be little or no correlation between th relative angle of jets and the dust residing in the galactic diskfor Seyfert galaxies (Kinney et al. 2000), the naive expectation is that the dust directly orbiting the black hole and the accretion disk is perpendicular to the jet.”
A Hubble Space Telescope Survey of Extended [O III] λ5007 Emission in a Far-Infrared Selected Sample of Seyfert Galaxies: Observations (2003, methodology): “We also compare the distances and luminosities of the observed galaxies with those of the entire Kinney et al (2000) sample, to verify that they are a representative subsample, and can be used to draw robust statistics on the Unified Model.”
Massive Black Hole Binary Evolution (2004, background): “Among the possible explanations [101] for the misalignment, perhaps the most natural is that SBH spins were determined by the same merger events that formed the bulge, long before the formation of the gaseous disk, and that subsequent spin-up by gas accretion from the disk plane has been minimal [13”
Alignment of the Spins of Supermassive Black Holes Prior to Coalescence (2007, result): “At first glance, alignment of black hole spin with the large scale angular momentum of the gas would seem to run contrary to the observation that Seyfert galaxies have jets that are randomly oriented relative to their host galaxy disks (Kinney et al. 2000).”
Formation of Galactic Nuclei (2001, background): “The number of mergers that have contributed to the growth of supermassive BHs might also be constrained by the almost random observed orientation of radio jets with respect to galactic disks in Seyfert galaxies (Kinney et al. 2000).”
Revisiting the Unified Model of Active Galactic Nuclei (2015, methodology): “For example, Kinney et al. (2000) used information from radio jet position angles and claimed to find no correlation between jet direction (i.e. inner accretion disk orientation) and the disk of the host galaxy.”
Radio Loudness of Active Galactic Nuclei: Observational Facts and Theoretical Implications (2006, result): “[6]) is severe but consistent with observations indicating very short lifetimes of individual accretion events in Seyfert galaxies (Capetti et al. 1999; Kharb et al. 2006) and showing a random orientation of jets relative to the host galaxy axis (Kinney et al. 2000; Schmitt et al. 2001).”
A Survey of Kiloparsec-Scale Radio Outflows in Radio-Quiet Active Galactic Nuclei (2006, background): “…that the orientation of the KSR axis is effectively random with respect to the optical major axis of the host galaxy (see, e.g., Nagar &Wilson 1999; Kinney et al. 2000), and it seems unlikely that starburst-driven superwinds, at least of the kind observed to occur in starburst nuclei, dominate the…”
AGN Dusty Tori. II. Observational Implications of Clumpiness (2008, unknown): “…dependence of the absorption cannot be attributed to the host galaxy because the AGN axis, as traced by the jet position angle, is randomly oriented with respect to the galactic disk in Seyfert galaxies (Kinney et al. 2000) and the nuclear dust disk in radio galaxies (Schmitt et al. 2002).”
The SAMI Galaxy Survey: shocks and outflows in a normal star-forming galaxy (2014, background): “Both energy injections from an AGN or central starburst can yield very similar bipolar structures, although the orientations of AGN-driven outflows can be random relative to the major axis of the host galaxy (e.g., Ulvestad & Wilson 1984; Cecil, Bland & Tully 1990; Kinney et al. 2000).”
Ejection of Supermassive Black Holes from Galaxy Cores (2007, background): “However there is considerable circumstantial evidence that SMBH spin axes bear no relation to the orientations of the gas disks that surround them (Kinney et al. 2000; Gallimore et al. 2006; Borguet et al. 2007) and this is presumably even more true with respect to the directions of infalling BHs…”