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The multi-wavelength properties of nearby low-luminosity Active Galactic Nuclei (LLAGN) with the Legacy e-MERLIN Multi-band Imaging of Nearby Galaxies survey (LeMMINGs)

The multi-wavelength properties of nearby low-luminosity Active Galactic Nuclei (LLAGN) with the Legacy e-MERLIN Multi-band Imaging of Nearby Galaxies survey (LeMMINGs)
The multi-wavelength properties of nearby low-luminosity Active Galactic Nuclei (LLAGN) with the Legacy e-MERLIN Multi-band Imaging of Nearby Galaxies survey (LeMMINGs)
The radio and multi-wavelength properties of active galactic nuclei (AGN) have been well documented in the literature, contributing to the unified picture of AGN as a super-massive black hole surrounded by various sub-structures. The study of low-luminosityAGN(LLAGN) is less well documented or understood, due largely to their intrinsic faintness. In this thesis, I study the radio emission of a statistically-complete sample of 280 nearby LLAGN using the Legacy e-MERLIN Multi-band Imaging of Nearby Galaxies survey (LeMMINGs), to detect the presence of kpc-scale radio jets. I compare the radio emission to the multi-wavelength properties of the host galaxy and LLAGN to understand the physical accretion mechanism in different types of LLAGN system. First, I present two in-depth multi-wavelength case studies of nearby LLAGN, observed with the LeMMINGs ‘deep’ survey: NGC4151 and NGC6217, studying long-term variability and the nuclear structures in these sources. I then present the LeMMINGs ‘shallow’ survey radio data for a statistically-complete sample of 280 nearby LLAGN based off the Palomar survey. I compare these observations with other available data in the literature, including X-ray observations from the Chandra X-ray Observatory to assess the multi-wavelength correlations of different types of LLAGN. Furthermore, I denote a type of star-forming galaxy, namely the ‘jetted H II galaxies’, that show similar multi-wavelength properties to that of other LLAGN, indicating that they may be hiding a LLAGN. Finally, the Fundamental Plane of Black Hole Activity (FPBHA) is correlation between the X-ray luminosity, radio luminosity and mass for black holes, spanning over eight orders of mass from Black hole X-ray binaries (BHXRBs) upto super-massive black holes in AGN. I construct the FPBHA for the LeMMINGs ‘shallow’ sample objects, including a sub-sample of BHXRBs, to investigate the correlation coefficients of the plane and test its validity with LLAGN sources. The results are consistent with previous formulations of the FPBHA but suggest that choice of LLAGN sub-sample is important for regressing the FPBHA parameters.
University of Southampton
Williams, David Richard Alexander
c9ded967-198f-4c26-96b1-8c03d7d26445
Williams, David Richard Alexander
c9ded967-198f-4c26-96b1-8c03d7d26445
McHardy, Ian
4f215137-9cc4-4a08-982e-772a0b24c17e

Williams, David Richard Alexander (2018) The multi-wavelength properties of nearby low-luminosity Active Galactic Nuclei (LLAGN) with the Legacy e-MERLIN Multi-band Imaging of Nearby Galaxies survey (LeMMINGs). University of Southampton, Doctoral Thesis, 444pp.

Record type: Thesis (Doctoral)

Abstract

The radio and multi-wavelength properties of active galactic nuclei (AGN) have been well documented in the literature, contributing to the unified picture of AGN as a super-massive black hole surrounded by various sub-structures. The study of low-luminosityAGN(LLAGN) is less well documented or understood, due largely to their intrinsic faintness. In this thesis, I study the radio emission of a statistically-complete sample of 280 nearby LLAGN using the Legacy e-MERLIN Multi-band Imaging of Nearby Galaxies survey (LeMMINGs), to detect the presence of kpc-scale radio jets. I compare the radio emission to the multi-wavelength properties of the host galaxy and LLAGN to understand the physical accretion mechanism in different types of LLAGN system. First, I present two in-depth multi-wavelength case studies of nearby LLAGN, observed with the LeMMINGs ‘deep’ survey: NGC4151 and NGC6217, studying long-term variability and the nuclear structures in these sources. I then present the LeMMINGs ‘shallow’ survey radio data for a statistically-complete sample of 280 nearby LLAGN based off the Palomar survey. I compare these observations with other available data in the literature, including X-ray observations from the Chandra X-ray Observatory to assess the multi-wavelength correlations of different types of LLAGN. Furthermore, I denote a type of star-forming galaxy, namely the ‘jetted H II galaxies’, that show similar multi-wavelength properties to that of other LLAGN, indicating that they may be hiding a LLAGN. Finally, the Fundamental Plane of Black Hole Activity (FPBHA) is correlation between the X-ray luminosity, radio luminosity and mass for black holes, spanning over eight orders of mass from Black hole X-ray binaries (BHXRBs) upto super-massive black holes in AGN. I construct the FPBHA for the LeMMINGs ‘shallow’ sample objects, including a sub-sample of BHXRBs, to investigate the correlation coefficients of the plane and test its validity with LLAGN sources. The results are consistent with previous formulations of the FPBHA but suggest that choice of LLAGN sub-sample is important for regressing the FPBHA parameters.

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Published date: September 2018

Identifiers

Local EPrints ID: 428650
URI: http://eprints.soton.ac.uk/id/eprint/428650
PURE UUID: 7c0aed8f-a313-4883-a594-29f1081209b4
ORCID for David Richard Alexander Williams: ORCID iD orcid.org/0000-0001-7361-0246

Catalogue record

Date deposited: 05 Mar 2019 17:30
Last modified: 14 Mar 2019 01:30

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Contributors

Author: David Richard Alexander Williams ORCID iD
Thesis advisor: Ian McHardy

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