The clustering of ALFALFA galaxies: dependence on HI mass, relationship to optical samples & clues on host halo properties

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We use a sample of ~6000 galaxies detected by the Arecibo Legacy Fast ALFA (ALFALFA) 21cm survey, to measure the clustering properties of HI-selected galaxies.

• We find no convincing evidence for a dependence of clustering on the galactic atomic hydrogen (HI) mass, over the range M_HI ~ 10^{8.5} - 10^{10.5} M_sun.
• We show that previously reported results of weaker clustering for low-HI mass galaxies are probably due to finite-volume effects.
• In addition, we compare the clustering of ALFALFA galaxies with optically selected samples drawn from the Sloan Digital Sky Survey (SDSS).