Searching in HI for Massive Low Surface Brightness Galaxies: Samples from HyperLeda and the UGC

TL;DR

This study searches for massive low surface brightness galaxies using 21 cm HI line emission in samples from HyperLeda and UGC, detecting many and identifying at least 31 as truly massive, revealing no clear correlation with surface brightness.

Contribution

It provides the first large-scale HI survey of low surface brightness galaxies from HyperLeda and UGC, identifying a significant number of massive LSB galaxies.

Findings

84.3% detection rate of HI in the sample

At least 31 galaxies are massive LSB with HI mass ≥ 10^10 M_sun

No clear trend between surface brightness and galaxy mass

Abstract

A search has been made for 21 cm HI line emission in a total of 350 unique galaxies from two samples whose optical properties indicate they may be massive The first consists of 241 low surface brightness (LSB) galaxies of morphological type Sb and later selected from the HyperLeda database and the the second consists of 119 LSB galaxies from the UGC with morphological types Sd-m and later. Of the 350 unique galaxies, 239 were observed at the Nancay Radio Telescope, 161 at the Green Bank Telescope, and 66 at the Arecibo telescope. A total of 295 (84.3%) were detected, of which 253 (72.3%) appear to be uncontaminated by any other galaxies within the telescope beam. Finally, of the total detected, uncontaminated galaxies, at least 31 appear to be massive LSB galaxies, with a total HI mass $\ge$ 10$^{10}$ M$_{sol}$, for H$_0$ = 70 km/s/Mpc. If we expand the definition to also include galaxies with significant total (rather than just gas) mass, i.e., those with inclination-corrected HI line width W$_{50}$,cor > 500 km/s, this bring the total number of massive LSB galaxies to 41. There are no obvious trends between the various measured global galaxy properties, particularly between mean surface brightness and galaxy mass.