I have just completed my PhD at the Mullard Space Science Laboratory in the heart of the Surrey Hills, where I was under the supervision of Prof. Graziella Branduardi-Raymont and
Prof. Mat Page . Before this, I did an integrated Masters degree in Physics with Astrophysics at the University of Leicester .
My interests are in research, data analysis, and problem solving. I have run outreach projects for school students to explore real X-ray data of AGN and have their worked published, organised seminars, and presented my research at conferences.
Research Interests:
I study the outflowing winds of AGN using X-ray data collected by ESA's XMM-Newton telescope. Observations peer into the heart of galaxies, where their supermassive black holes lie.
For an explanation on what AGN and AGN winds are, see the AGN Winds webpage.
The key questions I want to explore are:
- What are the origins and launching mechanisms of these winds?
- Where are these winds located with respect to the central black hole?
- Are these winds energetic enough to influence galaxy star formation?
- Are the warm absorber and narrow line region regions the same, just seen along different lines of sight?
- How do radio emitting outflows effect the observed plasma processes?
To answer these questions, I undertake the following:
- Analyse the high-resolution X-ray spectra with the SPEX code to create models that give insight into the properties of the wind and intrinsic AGN continuum.
- Study the emission and absorption features in the XMM-Newton Reflection Grating Spectrometer (RGS) spectra.
- Estimate the plasma wind locations with respect to the central black hole, allowing me to infer about the eenergetics of the wind.
- Compare different AGN together to build an overall picture of these complex environments.
- Led an XMM-Newton observation proposal to explore an AGN that shows possible outflow-induced star formation.
Recent First Author Papers
- S. Grafton-Waters , J. Mao, G. Branduardi-Raymont, J. Kaastra, M. Mehdipour, et al., submitted, A&A,
Transient obscuration event captuorange in NGC 3227 IV. Origin of the obscuration cloud variability
- S. Grafton-Waters and W. Dunn, 2021c, RNAAS, 5, 233,
A Study of the Soft X-ray Emission Lines in NGC 4151 II. The Internal Plasma Properties
- S. Grafton-Waters et al., 2021b, RNAAS, 5, 172,
A Study of the Soft X-ray Emission Lines in NGC 4151 I. Kinematic Properties of the Plasma Wind
- S. Grafton-Waters , G. Branduardi-Raymont, M. Mehdipour, et al., 2021, A&A, 649, A162,
Photoionisation Modelling of the X-ray Emission Line Regions within the Seyfert 2 AGN NGC 1068
- S. Grafton-Waters , G. Branduardi-Raymont, M. Mehdipour, M. Page, et al., 2020, A&A, 633 A62,
Multi-wavelength campaign on NGC 7469. VI. Photoionisation modelling of the emission line regions and the warm absorber
Recent Co-author Papers
- L. Gu, J. Mao, J. Kaastra ... S. Grafton-Waters , et al., 2022 Accepted , A&A, arXiv,
Detection of an Unidentified Soft X-ray Emission Feature in NGC 5548
- J. Mao, J. Kaastra, M. Mehdipour ... S. Grafton-Waters , et al., 2022, A&A,
Transient obscuration event captuorange in NGC 3227 III. The X-ray obscuration events in 2019
- Y. Wang, J. Kaastra, M. Mehdipour ... S. Grafton-Waters , et al., 2022, A&A, 657, A77
Transient obscuration event captuorange in NGC 3227 II. Warm absorbers and obscuration events in archival XMM-Newton and NuSTAR observations
- M. Mehdipour, G. Kriss, J. Kaastra, ... S. Grafton-Waters , et al., 2021, A&A, 652, A150
Transient obscuration event captuorange in NGC 3227. I. Continuum model for the broadband spectral energy distribution
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New Results in X-ray Astronomy Meeting 2022 , Leicester, UK, 26th May 2022
Presentation: The Obscuration Transient Event in NGC 3227 during 2019
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Seminar - MSSL, UK, 24th February 2022
Obscuration in AGN: NGC 5548, NGC 3783, and the 2019 Transient Event in NGC 3227
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Accretion Disk Winds Conference , Durham, UK (Remote) 9th September 2021
Presentation: Origin of the X-ray Narrow Line Region
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Seminar - Leicester, UK (Remote), 10th December 2020
Outflowing winds of Active Galactic Nuclei
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Seminar - MSSL, UK, 10th October 2019
Photoionisation Modelling of the Emission Line Regions in AGN
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New Results in X-ray Astronomy 2019 Conference , MSSL, UK, 4th September 2019
Presentation: Photoionisation Modelling of the Emission Line Regions in NGC 7469
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Xcalibur: Next generation X-ray spectroscopy , Winchester, UK, 15th July 2019
Poster Presentation: Multiwavelength Campaign on NGC 7469: Photoionisation Modelling of the Emission Line Regions
I submitted a research proposal for 20th XMM-Newton Announcement of Opportunity study the AGN NGC 5643 for 2021/22 observations. I led and wrote the proposal, implementing the science goals and
data analysis, as well as working with some collaborators to make sure the proposal was valid. The proposal was accepted.
Co-Investigators: G. Branduardi-Raymont, M. Page, P. Boorman, M. Symeonidis, and D. Walton
The abstract can be found here.
Outreach and public engagement activities are crucial in developing and inspiring the next generation into STEM subjects, and allowing them to reach their full potential.
During my PhD, I was lucky enough to run two projects, based on my research, as part of the ORBYTS education program at UCL.
You can see details of the projects I have run at the AGN Projects webpage.
Key Links:
UCL outreach page
MSSL Outreach page
UCL ORBYTS
Python Code
The Python code can be can be found on my Github page
Please cite the Zenodo reference if running a similar project
Blogs
I have written some blogs to the MSSL website:
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JOURNEY TO THE CENTRE OF A GALAXY: ACTIVE GALACTIC NUCLEI
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XMM-NEWTON: 20 YEARS AND COUNTING
Education
Ph.D at MSSL Sept 2017 - Feb 2022
Thesis Title: Exploring Photoionised Outflowing Winds in Active Galactic Nuclei
Supervisors: Graziella Branduardi-Raymont and Mat Page
Undergraduate degree, University of Leicester Sept 2013 - July 2017
MPhys - First Class Hons
MPhys Dissertation Title: Tracking X-rays in Galactic Black Holes
Supervisor: Simon Vaughan
A-Levels, John Masefield High School, Ledbury Sept 2011 - July 2013
Maths: A, Chemistry: B, Physics: C
Key Skills
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Programming: Python, R
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Spectral Codes: SPEX, XSPEC
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Document processors: LATEX, Microsoft Office
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Communication Platforms: Zoom, Microsoft Teams
Email:
sam.waters.17@ucl.ac.uk
Address:
Mullard Space Science Laboratory
University College London
Holmbury St. Mary
Dorking
Surrey
RH5 6NT
UK