AGNOsc

Code for AGN Oscillator project described in the paper titled "Statistical evidence for massive black hole recoils in active galactic nuclei" by Becsy, B., Raffai, P., Haiman, Z., Budai, A., & Frei, Z.

The analysis can be reproduced by running a mix of python and MATLAB codes in the workflow outlined below. We also provide intermediate data files for those who want to access the results without rerunning the entire analysis (Step 3 below).

Workflow

1. The analysis starts with data files from the SDSS DR16Q Calatog [1] and the spectral analyses of Wu & Shen (2022) [2], which are available from [3] and [4] respectively. The first step is to run through the prefilter_and_dgmi_calc.ipynb notebook. This selects the requered columns from the Wu & Shen (2022) data, applies some necessary filters, and calculates dgmi (and dgmr) values based on the SDSS data. Then it crossmatches these and produces a combined txt data file needed for the next step.
2. The data file produced in step 1 is processed with the QSO_Oscillator.m MATLAB code, which calculates Dv line-of-sight velocities between the selected broad line and a collection of narrow lines, and it applies additional quality cuts. It performs the correlation test between Dv and dgmi. It also outputs all the data to a txt file.
3. The output file of step 2 can be used to reproduce Figs 1-6 of our paper via running through the plotting.ipynb notebook. The output file required for this is also provided in the data directory of the repository, so the plots can be reproduced without going through the full workflow.

[1] Lyke, B. W. et al., “The Sloan Digital Sky Survey Quasar Catalog: Sixteenth Data Release”, The Astrophysical Journal Supplement Series, vol. 250, no. 1, Art. no. 8, IOP, 2020. doi:10.3847/1538-4365/aba623. https://ui.adsabs.harvard.edu/abs/2020ApJS..250....8L/abstract

[2] Wu, Q. and Shen, Y., “A Catalog of Quasar Properties from Sloan Digital Sky Survey Data Release 16”, The Astrophysical Journal Supplement Series, vol. 263, no. 2, Art. no. 42, IOP, 2022. doi:10.3847/1538-4365/ac9ead. https://ui.adsabs.harvard.edu/abs/2022ApJS..263...42W/abstract

[3] http://quasar.astro.illinois.edu/paper_data/DR16Q/dr16q_prop_May01_2024.fits.gz

[4] https://data.sdss.org/sas/dr16/eboss/qso/DR16Q/DR16Q_v4.fits