NGC 4151 Project

The first project I ran for ORBYTS was with year 10 and 12 students from the Nottingham University Academy for Science and Technology (NUAST) where we explored the AGN NGC 4151.

The aim of this project was to assess whether the NLR properties changed between observations spanning a 15 year period, by measuring the outflow velocities and distances of each region. By analysing the strongest emission lines seen in the XMM-Newton Reflection Grating Spectrometer (RGS) spectrum of 27 observations spanning six epochs between 2000 and 2015.

Spectrum
This figure shows the RGS spectrum from the 2015 epoch, made up of nine different observations (grey line). The insert shows the O VII forbidden line fitted with its respective Gaussian. To each of the strongest lines, as labelled, the students fitted a simple Gaussian model (orange lines) to measure the observed wavelength. This wavelength was used to measure the outflow velocity of the plasma region that produced each line, which was then used to determine the distance from the central SMBH.
Vel_Dist
This figure displays the outflow velocities (top) and distances (bottom) from fitting each line with a Gaussian. The 2000 (left) and 2015 (right) observations are compared together to determine whether there are any groupings in velocity and distance. The black dashed lines indicate the plasma boundaries suggesting that there are at least two to three plasma regions.

The velocities and distances are consistent throughout the observations, implying that there is no change in the NLR properties over a 15 year observation period.

The paper can be seen here

The Python code can be can be found on my Github page
Please cite the Zenodo reference if running a similar project

Project Feedback

Before and after this project, 80% of students were likely to pursue a career in science.

Before starting this project, 60% of students were unlikely to pursue a career in research. But after the completing the project, 60% said that they were likely to pursue a career in research.

100% of students said that they would recommend the program to a friend.

piecharts

Quotes

  • "You made the project an enjoyable experience and taught us important skills that we will likely rely on later in our studies"
  • "You were good at helping me correct the error messages and understand where the code was wrong and how to then solve it by myself"
  • "Despite being an extremely in-depth advanced topic I was able to understand the broad idea of what we were doing"
  • "You clearly explained any key ideas and then expanded upon them and explained in detail the cause of the spectra we were studying"
  • "Very helpful and responsive with any problems I faced"