Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Competitive feedback in galaxy formation   It is now well established that many galaxies have nuclear star clusters
(NCs) whose total masses correlate with the velocity dispersion (sigma) of the
galaxy spheroid in a very similar way to the well--known supermassive black
hole (SMBH) M - sigma relation. Previous theoretical work suggested that both
correlations can be explained by a momentum feedback argument. Observations
further show that most known NCs have masses < 10^8 Msun, while SMBHs
frequently have masses > 10^8 Msun, which remained unexplained in previous
work. We suggest here that this changeover reflects a competition between the
SMBH and nuclear clusters in the feedback they produce. When one of the massive
objects reaches its limiting M-sigma value, it drives the gas away and hence
cuts off its own mass and also the mass of the ``competitor''. The latter is
then underweight with respect to the expected M-sigma mass (abridged).

37
The categories of this paper are: supr-con
3
The categories of this paper are: physics
31
The categories of this paper are: ao-sci
1
The categories of this paper are: cs
17
The categories of this paper are: q-fin
21
The categories of this paper are: adap-org
15
The categories of this paper are: nucl-ex
23
The categories of this paper are: solv-int
26
The categories of this paper are: bayes-an
2
The categories of this paper are: math
13
The categories of this paper are: quant-ph
10
The categories of this paper are: q-bio
11
The categories of this paper are: hep-lat
5
The categories of this paper are: gr-qc
12
The categories of this paper are: nucl-th
4
The categories of this paper are: cond-mat