Toward Cosmicflows-4: The \hi data catalog
  In this study, we present an update of a compilation of line width
measurements of neutral atomic hydrogen (HI) galaxy spectra at 21 cm
wavelength. Our All Digital HI (ADHI) catalog consists of the previous release
augmented with our new HI observations and an analysis of archival data. This
study provides the required HI information to measure the distances of spiral
galaxies through the application of the Tully-Fisher (TF) relation. We
conducted observations at the Green Bank telescope (GBT) and reprocessed
spectra obtained at the Nancay radiotelescope by the Nancay Interstellar
Baryons Legacy Extragalactic Survey (NIBLES) and Kinematics of the Local
Universe (KLUN) collaborations and we analyzed the recently published full
completion Arecibo Legacy Fast ALFA (ALFALFA) 100% survey in order to identify
galaxies with good quality HI line width measurements. This paper adds new HI
data adequate for TF use for 385 galaxies observed at GBT, 889 galaxies from
archival Nancay spectra, and 1,515 rescaled Arecibo ALFALFA spectra. In total,
this release adds 1,274 new good quality measurements to the ADHI catalog.
Today, the ADHI database contains 18,874 galaxies, for which 15,433 have good
quality data for TF use. The final goal is to compute accurate distances to
spiral galaxies, which will be included in the next generation of peculiar
velocities catalog: Cosmicflows-4.
