Intermediate-Mass Black Holes

By Jenny E. Greene, J. Strader, Luis C. Ho. 2019

472 citations recorded by the source corpus.

We describe ongoing searches for intermediate-mass black holes with M_BH ~ 100-10^5 M_sun. We review a range of search mechanisms, both dynamical and those that rely on accretion signatures. We find that dynamical and accretion signatures alike point to a high fraction of 10^9-10^10 M_sun galaxies hosting black holes with M_BH<10^5 M_sun. In contrast, there are no solid detections of black holes in globular clusters. There are few observational constraints on black holes in any environment with M_BH ~ 100-10^4 M_sun. Considering low-mass galaxies with dynamical black hole masses and constraining limits, we find that the M_BH-sigma_* relation continues unbroken to M_BH~10^5 M_sun, albeit with large scatter. We believe the scatter is at least partially driven by a broad range in black hole mass, since the occupation fraction appears to be relatively high in these galaxies. We fold the observed scaling relations with our empirical limits on occupation fraction and the galaxy mass function to put observational bounds on the black hole mass function in galaxy nuclei. We are pessimistic that local demographic observations of galaxy nuclei alone could constrain seeding mechanisms, although either high-redshift luminosity functions or robust measurements of off-nuclear black holes could begin to discriminate models.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/6d1a38d1c34063b4d6ad4b3a70a7fb5a72d0e325

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In Astronomy and Astrophysics

1. Marek Lewicki
2. John Ellis
3. V. Vaskonen
4. Floor Broekgaarden
5. O. Buchmueller
6. S. Carniani
7. D. Blas
8. M. Haehnelt

In Instrumentation

1. S. Carniani
2. M. Haehnelt
3. Floor Broekgaarden
4. John Ellis
5. Ilya Mandel
6. R. Maiolino
7. C. McCabe
8. V. Vaskonen

Citations in the corpus

• JWST CEERS and JADES Active Galaxies at z = 4–7 Violate the Local M •–M ⋆ Relation at >3σ: Implications for Low-mass Black Holes and Seeding Models (2023, background): “…flavors of black hole seeds (see, e.g., Hirschmann et al. 2010; Pacucci et al. 2017; Visbal & Haiman 2018; Pacucci et al. 2018; Nguyen et al. 2019; Greene et al. 2020; King & Nealon 2021; Hu et al. 2022; Koudmani et al. 2022; Schneider et al. 2023; Scog-gins et al. 2023; Scoggins & Haiman 2023).”
• Rates of compact object coalescences (2021, background): “The challenges associated with observing IMBHs are discussed by Miller and Colbert (2004) and Greene et al. (2019). Given the many orders of magnitude uncertainties, we resist the temptation to review”
• AION: an atom interferometer observatory and network (2019, methodology): “For IMBHs in the Milky Way with masses in the range of a few ×103 to ∼ 106 solar masses these transitions would give frequencies inside the AION sensitivity region.”