Extended Data Fig. 4

BDDGs data. Column 1 shows the ALFALFA galaxy ID; columns 2 and 3 show equatorial coordinates; column 4 shows the distance judged by ALFALFA group; column 5 shows the heliocentric velocity; column 6 shows the velocity width for 20% of the peak flux; column 7 shows the error of w₂₀; columns 8 and 9 show the g-band and r-band magnitudes, respectively; column 10 shows the effective radius in the r-band; column 11 shows the neutral hydrogen mass; column 12 shows the stellar mass; column 13 shows the dynamical mass within r_H i; column 14 shows the virial mass; column15 shows the r-band minor-to-major axis ratio; and column 16 shows the distance to the nearest group over virial radius.

*In the literature AGC 6980 was defined as Abell 1367’s member (Leo cluster: \({\mathrm{c}}z = 6459\), RA = 176.15083, Dec. = 19.77194)⁵⁵. The projected distance between the AGC 6980 and Abell 1367 is about 8 Mpc, well beyond 3R_vir of the Abell 1367. ^†The minimum projected distance of the BDDG to its surrounding clusters with relatively small difference in redshifts (cz_BDDG – cz_cluster < 10 × R_cluster;vir) is <3 × R_vir.