Kavli Affiliate: Jing Wang
| First 5 Authors: Jing Wang, Dong Yang, Xuchen Lin, Qifeng Huang, Zhijie Qu
| Summary:
We present the HI surface density ($Sigma_{rm HI}$) radial distributions
based on total-power HI images obtained by FAST in the FEASTS program, for 35
galaxies with inclinations lower than 72 degree. We derive the HI radius
$R_{001}$, which is the radius for the 0.01 $,M_{odot},{rm pc}^{-2}$
($sim10^{18.1},{rm cm}^{-2}$) iso-density level, 100 times deeper than the 1
$,M_{odot},{rm pc}^{-2}$ level previously commonly used to measure $R_1$.
The profile shapes show a large diversity at a given radius in units of kpc,
group virial radius, and $R_1$, but align more tightly with radius normalized
by $R_{001}$. The universal HI profile has a scatter of $sim0.2$ dex, and a
scale-length of $sim0.11R_{001}$ in the outer region. We derive a new
$R_{001}$-$M_{rm HI}$ relation, which has a scatter of 0.02 dex, and similar
slope of $sim$0.5 as the previously known $R_1$-$M_{rm HI}$ relation.
Excluding strongly tidal-interacting galaxies, the ratio $R_{001}/R_1$
(anti-)correlate strongly and significantly with the HI-to-stellar mass ratio
and sSFR, but not with the stellar mass, $M_{rm HI}$, dark matter mass, or
SFR. The strongly tidal-interacting galaxies tend to show deviations from these
trends, and have the most flattened profiles. These results imply that in
absence of major tidal interactions, physical processes must cooperate so that
$Sigma_{rm HI}$ distributes in a self-similar way in the outer region down to
the 0.01$,M_{odot},{rm pc}^{-2}$ level. Moreover, they may drive gas flows
in such a way, that HI-richer galaxies have HI disks not only extend further,
but also transport HI inward more efficiently from $R_{001}$ to $R_1$.
| Search Query: ArXiv Query: search_query=au:”Jing Wang”&id_list=&start=0&max_results=3