Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The HI content of dark matter halos at $z\approx 0$ from ALFALFA   We combine information from the clustering of HI galaxies in the 100% data
release of the Arecibo Legacy Fast ALFA survey (ALFALFA), and from the HI
content of optically-selected galaxy groups found in the Sloan Digital Sky
Survey (SDSS) to constrain the relation between halo mass $M_h$ and its average
total HI mass content $M_{\rm HI}$. We model the abundance and clustering of
neutral hydrogen through a halo-model-based approach, parametrizing the $M_{\rm
HI}(M_h)$ relation as a power law with an exponential mass cutoff. To break the
degeneracy between the amplitude and low-mass cutoff of the $M_{\rm HI}(M_h)$
relation, we also include a recent measurement of the cosmic HI abundance from
the $\alpha$.100 sample. We find that all datasets are consistent with a
power-law index $\alpha=0.44\pm 0.08$ and a cutoff halo mass $\log_{10}M_{\rm
min}/(h^{-1}M_\odot)=11.27^{+0.24}_{-0.30}$. We compare these results with
predictions from state-of-the-art magneto-hydrodynamical simulations, and find
both to be in good qualitative agreement, although the data favours a
significantly larger cutoff mass that is consistent with the higher cosmic HI
abundance found in simulations. Both data and simulations seem to predict a
similar value for the HI bias ($b_{\rm HI}=0.875\pm0.022$) and shot-noise power
($P_{\rm SN}=92^{+20}_{-18}\,[h^{-1}{\rm Mpc}]^3$) at redshift $z=0$.

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The categories of this paper are: patt-sol
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The categories of this paper are: plasm-ph
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The categories of this paper are: comp-gas
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The categories of this paper are: ao-sci
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The categories of this paper are: math
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The categories of this paper are: bayes-an
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The categories of this paper are: hep-th
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The categories of this paper are: hep-ex
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The categories of this paper are: chem-ph
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The categories of this paper are: econ
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The categories of this paper are: solv-int
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The categories of this paper are: gr-qc
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The categories of this paper are: supr-con
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The categories of this paper are: funct-an
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The categories of this paper are: adap-org
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The categories of this paper are: q-bio