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Abstract / Description of output
We present the identification and analysis of an unbiased sample of
active galactic nuclei (AGN) that lie within the local galaxy
population. Using the MPA-JHU catalogue (based on SDSS DR8) and 3XMM DR7
we define a parent sample of 25 949 local galaxies (z ≤ 0.33).
After confirming that there was strictly no AGN light contaminating
stellar mass and star-formation rate calculations, we identified 917
galaxies with central, excess X-ray emission likely originating from an
AGN. We analysed their optical emission lines using the BPT diagnostic
and confirmed that such techniques are more effective at reliably
identifying sources as AGN in higher mass galaxies: rising from
30 per cent agreement in the lowest mass bin to 93 per cent in the
highest. We then calculated the growth rates of the black holes powering
these AGN in terms of their specific accretion rates (∝LX/M*). Our sample exhibits a wide range of accretion rates, with the majority accreting at rates ≤0.5 percent
of their Eddington luminosity. Finally, we used our sample to calculate
the incidence of AGN as a function of stellar mass and redshift. After
correcting for the varying sensitivity of 3XMM, we split the galaxy
sample by stellar mass and redshift and investigated the AGN fraction as
a function of X-ray luminosity and specific black hole accretion rate.
From this we found the fraction of galaxies hosting AGN above a fixed
specific accretion rate limit of 10−3.5 is constant (at ≈1 percent) over stellar masses of 8 < log M*/M⊙ < 12 and increases (from ≈1 percent to 10 per cent) with redshift.
Original language | English |
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Pages (from-to) | 4556-4572 |
Number of pages | 17 |
Journal | Monthly Notices of the Royal Astronomical Society |
Volume | 510 |
Issue number | 3 |
Early online date | 10 Dec 2021 |
DOIs | |
Publication status | Published - 1 Mar 2022 |
Keywords / Materials (for Non-textual outputs)
- astro-ph.GA
- astro-ph.HE
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Dive into the research topics of 'The Incidence of X-ray selected AGN in Nearby Galaxies'. Together they form a unique fingerprint.Projects
- 1 Finished
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Connecting the lifecycles of galaxies and their central black holes
1/11/20 → 31/10/24
Project: Research