Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Metal Enrichment of the Intergalactic Medium and Production of Massive
  Black Holes   A model for the chemical evolution of the intergalactic medium (IGM) is
presented using theoretical yields of very massive stars (VMSs) and Type II
supernovae (SNe II). It is shown that if [Si/C] is indeed as high as ~0.7 in
the IGM, then VMSs associated with pair-instability supernovae (PI-SNe) in
low-mass halos at high redshift must produce at least 50% of the Si. The
remainder is from later galactic outflows of SN II debris, which also provide
most of the C and O. Both sources are required to account for the metal
inventory in the IGM. The early VMS production must continue until redshift
z~15 so that the efficiency of VMS formation per low-mass halo is significantly
below unity. Contributions from the later galactic outflows mainly occur at
z~4-6. Using a Salpeter initial mass function, we infer that the number of VMSs
producing massive black holes (MBHs) is 0.72 times the the number of VMSs
associated with PI-SNe. The amount of metals (particularly Si) in the IGM that
is attributable to PI-SNe is thus closely coupled with the total mass of MBHs
produced in epochs prior to galaxy formation. Production of ~50% of the Si in
the IGM by PI-SNe corresponds to an early inventory of MBHs that is comparable
to the global mass budget of the central supermassive black holes in
present-day galaxies. (Abridged)

19
The categories of this paper are: eess
7
The categories of this paper are: hep-th
3
The categories of this paper are: physics
30
The categories of this paper are: q-alg
15
The categories of this paper are: nucl-ex
37
The categories of this paper are: supr-con
22
The categories of this paper are: chao-dyn
5
The categories of this paper are: gr-qc
32
The categories of this paper are: atom-ph
2
The categories of this paper are: math
28
The categories of this paper are: alg-geom
33
The categories of this paper are: plasm-ph
18
The categories of this paper are: econ
23
The categories of this paper are: solv-int
1
The categories of this paper are: cs
14
The categories of this paper are: math-ph