1 Brodie, J. P., Romanowsky, A. J., Strader, J. & Forbes, D. A. The relationships among compact stellar systems: a fresh view of ultracompact dwarfs. Astron. J. 142, 199 (2011)

2 Mieske, S. et al. On central black holes in ultra-compact dwarf galaxies. Astron. Astrophys. 558, A14 (2013)

3 Frank, M. J. et al. Spatially resolved kinematics of an ultracompact dwarf galaxy. Mon. Not. R. Astron. Soc. 414, L70–L74 (2011)

4 Dabringhausen, J., Kroupa, P., Pflamm-Altenburg, J. & Mieske, S. Low-mass X-ray binaries indicate a top-heavy stellar initial mass function in ultracompact dwarf galaxies. Astrophys. J. 747, 72 (2012)

5 Strader, J. et al. The densest galaxy. Astrophys. J. 775, L6 (2013)

6 Blakeslee, J. P. et al. The ACS Fornax cluster survey. V. Measurement and recalibration of surface brightness fluctuations and a precise value of the Fornax–Virgo relative distance. Astrophys. J. 694, 556–572 (2009)

7 Schwarzschild, M. A numerical model for a triaxial stellar system in dynamical equilibrium. Astrophys. J. 232, 236–247 (1979)

8 van den Bosch, R. C. E., van de Ven, G., Verolme, E. K., Cappellari, M. & de Zeeuw, P. T. Triaxial orbit based galaxy models with an application to the (apparent) decoupled core galaxy NGC 4365. Mon. Not. R. Astron. Soc. 385, 647–666 (2008)

9 van den Bosch, R. C. E. & de Zeeuw, P. T. Estimating black hole masses in triaxial galaxies. Mon. Not. R. Astron. Soc. 401, 1770–1780 (2010)

10 Kormendy, J. & Ho, L. C. Coevolution (or not) of supermassive black holes and host galaxies. Annu. Rev. Astron. Astrophys. 51, 511–653 (2013)

11 Reines, A. E., Greene, J. E. & Geha, M. Dwarf galaxies with optical signatures of active massive black holes. Astrophys. J. 775, 116 (2013)

12 Gebhardt, K., Rich, R. M. & Ho, L. C. An intermediate-mass black hole in the globular cluster G1: improved significance from new Keck and Hubble Space Telescope observations. Astrophys. J. 634, 1093–1102 (2005)

13 Jalali, B. et al. A dynamical N-body model for the central region of ω Centauri. Astron. Astrophys. 538, A19 (2012)

14 van der Marel, R. P. & Anderson, J. New limits on an intermediate-mass black hole in Omega Centauri. II. Dynamical models. Astrophys. J. 710, 1063–1088 (2010)

15 Miller-Jones, J. C. A. et al. The absence of radio emission from the globular cluster G1. Astrophys. J. 755, L1 (2012)

16 van den Bosch, R. C. E. et al. An over-massive black hole in the compact lenticular galaxy NGC1277. Nature 491, 729–731 (2012)

17 Gallo, E. et al. AMUSE-Virgo. II. Down-sizing in black hole accretion. Astrophys. J. 714, 25–36 (2010)

18 Ho, L. C. Nuclear activity in nearby galaxies. Annu. Rev. Astron. Astrophys. 46, 475–539 (2008)

19 Mieske, S., Hilker, M. & Misgeld, I. The specific frequencies of ultra-compact dwarf galaxies. Astron. Astrophys. 537, A3 (2012)

20 Drinkwater, M. J. et al. A class of compact dwarf galaxies from disruptive processes in galaxy clusters. Nature 423, 519–521 (2003)

21 Pfeffer, J. & Baumgardt, H. Ultra-compact dwarf galaxy formation by tidal stripping of nucleated dwarf galaxies. Mon. Not. R. Astron. Soc. 433, 1997–2005 (2013)

22 Portegies Zwart, S. F., Baumgardt, H., Hut, P., Makino, J. & McMillan, S. L. W. Formation of massive black holes through runaway collisions in dense young star clusters. Nature 428, 724–726 (2004)

23 Graham, A. W. & Spitler, L. R. Quantifying the coexistence of massive black holes and dense nuclear star clusters. Mon. Not. R. Astron. Soc. 397, 2148–2162 (2009)

24 Ferrarese, L. et al. A fundamental relation between compact stellar nuclei, supermassive black holes, and their host galaxies. Astrophys. J. 644, L21–L24 (2006)

25 Côté, P. et al. The ACS Virgo cluster survey. VIII. The nuclei of early-type galaxies. Astrophys. J. 165 (suppl.). 57–94 (2006)

26 Turner, M. L. et al. The ACS Fornax cluster survey. VI. The nuclei of early-type galaxies in the Fornax cluster. Astrophys. J. 203 (suppl.). 5 (2012)

27 Strader, J., Caldwell, N. & Seth, A. C. Star clusters in M31. V. Internal dynamical trends: some troublesome, some reassuring. Astron. J. 142, 8 (2011)

28 Bastian, N., Covey, K. R. & Meyer, M. R. A universal stellar initial mass function? A critical look at variations. Annu. Rev. Astron. Astrophys. 48, 339–389 (2010)

29 Gültekin, K., Cackett, E. M., King, A. L., Miller, J. M. & Pinkney, J. Low-mass AGNs and their relation to the fundamental plane of black hole accretion. Astrophys. J. 788, L22 (2014)

30 Miller, M. C., Farrell, S. A. & Maccarone, T. J. A wind accretion model for HLX-1. Astrophys. J. 788, 116 (2014)

31 McGregor, P. J. et al. Gemini near-infrared integral field spectrograph (NIFS). In Instrument Design and Performance for Optical/Infrared Ground-based Telescopes (eds Iye, M. & Moorwood, A. F. M .) Proc. SPIE 4841, 1581–1591 (SPIE, 2003)

32 Seth, A. C. et al. The NGC 404 nucleus: star cluster and possible intermediate-mass black hole. Astrophys. J. 714, 713–731 (2010)

33 Wallace, L. & Hinkle, K. High-resolution spectra of ordinary cool stars in the K band. Astrophys. J. Suppl. Ser. 107, 312–390 (1996)

34 Cappellari, M. & Emsellem, E. Parametric recovery of line-of-sight velocity distributions from absorption-line spectra of galaxies via penalized likelihood. Publ. Astron. Soc. Pacif. 116, 138–147 (2004)

35 Cappellari, M. & Copin, Y. Adaptive spatial binning of integral-field spectroscopic data using Voronoi tessellations. Mon. Not. R. Astron. Soc. 342, 345–354 (2003)

36 Husser, T.-O. et al. A new extensive library of PHOENIX stellar atmospheres and synthetic spectra. Astron. Astrophys. 553, A6 (2013)

37 Emsellem, E., Monnet, G. & Bacon, R. The multi-gaussian expansion method: a tool for building realistic photometric and kinematical models of stellar systems. I. The formalism. Astron. Astrophys. 285, 723–738 (1994)

38 Cappellari, M. Efficient multi-Gaussian expansion of galaxies. Mon. Not. R. Astron. Soc. 333, 400–410 (2002)

39 van de Ven, G., de Zeeuw, P. T. & van den Bosch, R. C. E. Recovery of the internal orbital structure of galaxies. Mon. Not. R. Astron. Soc. 385, 614–646 (2008)

40 van den Bosch, R. C. E. & van de Ven, G. Recovering the intrinsic shape of early-type galaxies. Mon. Not. R. Astron. Soc. 398, 1117–1128 (2009)

41 Merritt, D. Dynamics and Evolution of Galactic Nuclei (Princeton Univ. Press, 2013)

42 Cappellari, M. Measuring the inclination and mass-to-light ratio of axisymmetric galaxies via anisotropic Jeans models of stellar kinematics. Mon. Not. R. Astron. Soc. 390, 71–86 (2008)

43 Cappellari, M. et al. Testing mass determinations of supermassive black holes via stellar kinematics. Preprint at http://arxiv.org/abs/1001.3233 (2010)

44 Schödel, R., Merritt, D. & Eckart, A. The nuclear star cluster of the Milky Way: proper motions and mass. Astron. Astrophys. 502, 91–111 (2009)

45 Tollerud, E. J., Bullock, J. S., Graves, G. J. & Wolf, J. From galaxy clusters to ultra-faint dwarf spheroidals: a fundamental curve connecting dispersion-supported galaxies to their dark matter halos. Astrophys. J. 726, 108 (2011)

46 Cappellari, M. et al. Systematic variation of the stellar initial mass function in early-type galaxies. Nature 484, 485–488 (2012)

47 Binney, J. & Tremaine, S. Galactic Dynamics 2nd edn (Princeton Univ. Press, 2008)

48 Dabringhausen, J., Kroupa, P. & Baumgardt, H. A top-heavy stellar initial mass function in starbursts as an explanation for the high mass-to-light ratios of ultra-compact dwarf galaxies. Mon. Not. R. Astron. Soc. 394, 1529–1543 (2009)

49 Seth, A. C. Gas accretion in the M32 nucleus: past and present. Astrophys. J. 725, 670–676 (2010)