The Roles of the Mid-infrared and Surveys in The Life and Times of Quasars

Lead Research Organisation: University of Edinburgh
Department Name: Sch of Physics and Astronomy

Abstract

Black holes are intriguing objects. These regions of the Universe where mass is so dense, and gravity so strong, that even light cannot escape, were once thought mere oddities due to their extreme properties. Today, however, black holes are now thought to be vital in the formation and lives of galaxies, including our own Milky Way.

Observations, including those from the Hubble Space Telescope, have discovered black holes with masses a million or more times that of the Sun lurking at the centres of nearby galaxies. However, upon analysing these data further, there are two very surprising findings. First, these aptly named "Supermassive Black Holes" are ubiquitous at the centres of galaxies, and second, there is a relationship between the mass of the black hole and the properties of the galaxy.

Thus, the question arises, do black holes have an intimate relationship with their host galaxy? Do they inform, limit and influence how a galaxy - including its constituent stars and gas - forms and evolves? One possible line of evidence supporting the idea that black holes "regulate" their host galaxies is when one considers the energy liberated by mass falling into the black holes potential well.

As gas and dust fall towards a black hole, but before it gets "swallowed", an accretion disk can form which swirls around the black hole, feeding it. However, due to the intense gravitational fields, the large amounts of angular momentum, and friction between the infalling layers of gas, the accretion disk can heat-up to tremendous temperatures, in the process emitting optical, ultra-violet and X-ray light. If a supermassive black hole at the centre of a galaxy is actively accreting, then this "active galactic nucleus" is termed a quasar.

The broad aim of my research is to discover and study quasars; to find out how they are fueled, how they generate their energy and how they can influence the host galaxies they live in.

I use several telescopes across a range of wavelengths, including data from the Sloan Digital Sky Survey and the Hubble Space Telescope in the optical, and the Spitzer Space Telescope and the WISE satellite in the infrared. The infrared is important since quasars emit a considerable amount of their energy at these wavelengths, and one goal is to make sure we account fully for the entire energy production from supermassive black holes.

It is with the data from these great observatories that I will discover and examine quasars, test theoretical and computer models of how quasars are fueled, and gain new insights into how the galaxy-quasar symbiosis is achieved.

This research has potential impact and wider benefits to society in two flavours. First, the direct technological spin-offs that are associated with e.g. space-based telescopes and detector technology. Second, and less tangible, but more importantly, this type of research, keeps the "awe" factor high. And it is this resource, from which "improving natural knowledge" subsequently flows.

Publications

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Alexandroff Rachael M. (2018) Spectropolarimetry of high-redshift obscured and red quasars in Monthly Notices of the Royal Astronomical Society

 
Description New analysis techniques for studying astronomical infrared data.
Exploitation Route Our analysis could be adapted and used for other applications that image manipulating large amounts of imaging data, or understanding the infrared properties of (non-astronomical) objects.
Sectors Aerospace, Defence and Marine,Agriculture, Food and Drink,Chemicals,Communities and Social Services/Policy,Construction,Creative Economy,Digital/Communication/Information Technologies (including Software),Education,Electronics,Energy,Environment,Healthcare,Government, Democracy and Justice,Culture, Heritage, Museums and Collections,Transport,Other

URL http://www.roe.ac.uk/~npross/
 
Description Scots for Science
Geographic Reach Local/Municipal/Regional 
Policy Influence Type Participation in a advisory committee
 
Description LBNL Observing
Amount $2,000 (USD)
Organisation Lawrence Berkeley National Laboratory 
Sector Public
Country United States
Start 12/2015 
End 01/2016
 
Description LSST:UK Travel Scheme
Amount £2,000 (GBP)
Organisation LSST Corporation 
Sector Charity/Non Profit
Country United States
Start 02/2019 
End 02/2019
 
Title My Research Tools & Methods 
Description https://github.com/d80b2t 
Type Of Material Improvements to research infrastructure 
Year Produced 2016 
Provided To Others? Yes  
Impact https://github.com/d80b2t 
URL https://github.com/d80b2t
 
Description Revolutionary Quasar Science with the JWST 
Organisation JWST-MIRI European Consortium
Country United Kingdom 
Sector Private 
PI Contribution I start the "Revolutionary Quasar Science with the JWST" programme and collaboration.
Collaborator Contribution All contributions are documented here: https://github.com/d80b2t/JWST_ERS
Impact All outputs are documented here: https://github.com/d80b2t/JWST_ERS
Start Year 2017
 
Description The 2dF-Spitzer Quasar Redshift Survey 
Organisation Drexel University
Country United States 
Sector Academic/University 
PI Contribution We/I P.I.'ed the project.
Collaborator Contribution Initial proposal writing; travel to take data; data analysis; experimental log keeping; publication of results and interpretation.
Impact Academic peer-reviewed journals.
Start Year 2015
 
Description The 2dF-Spitzer Quasar Redshift Survey 
Organisation Lawrence Berkeley National Laboratory
Country United States 
Sector Public 
PI Contribution We/I P.I.'ed the project.
Collaborator Contribution Initial proposal writing; travel to take data; data analysis; experimental log keeping; publication of results and interpretation.
Impact Academic peer-reviewed journals.
Start Year 2015
 
Description The 2dF-Spitzer Quasar Redshift Survey 
Organisation University of Edinburgh
Country United Kingdom 
Sector Academic/University 
PI Contribution We/I P.I.'ed the project.
Collaborator Contribution Initial proposal writing; travel to take data; data analysis; experimental log keeping; publication of results and interpretation.
Impact Academic peer-reviewed journals.
Start Year 2015
 
Description The 2dF-Spitzer Quasar Redshift Survey 
Organisation University of Wyoming
Country United States 
Sector Academic/University 
PI Contribution We/I P.I.'ed the project.
Collaborator Contribution Initial proposal writing; travel to take data; data analysis; experimental log keeping; publication of results and interpretation.
Impact Academic peer-reviewed journals.
Start Year 2015
 
Title My Analysis Code 
Description My Analysis Code. 
Type Of Technology Software 
Year Produced 2016 
Open Source License? Yes  
Impact Multiple research papers. 
URL https://github.com/d80b2t/
 
Description ROE Open DAy 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact 2015 ROE Open Days
"Weird New Worlds"
The ROE Open Days for 2015 took place over the weekend of the 26th and 27th of September.
The theme this year was Weird New Worlds
We had over 3000 visitors over the weekend.
Year(s) Of Engagement Activity 2015
URL http://www.stfc.ac.uk/news-events-and-publications/events/stfc-events/royal-observatory-edinburgh-op...
 
Description ROE Open Day Sep 2016 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Public/other audiences
Results and Impact Help at the ROE Open Day.
Year(s) Of Engagement Activity 2016