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We analyzed the properties of a sample of edge-on low-surface brightness galaxies, which are referred to as Cao23 ELSBGs. Cao23 ELSBGs exhibit a wide range of luminosities (−22 < Mr < −13) with a mean scale length of 3.19 ± 1.48 kpc. Compared to HI-rich dwarf ELSBGs, Cao23 ELSBGs display more extended disk structures and redder (g-r) colors. They are also, on average, more massive than HI-rich dwarf ELSBGs. Star formation rates (SFRs) were calculated using WISE 12 μm luminosity conversions and spectral energy distribution (SED) fitting methods, respectively. Cao23 ELSBGs fall below the main sequence with specific star formation rates (sSFRs) primarily in the range of 0.01–0.1 Gyr−1. More massive Cao23 LSBGs tend to have lower sSFRs. Additionally, we derived the non-parametric star formation histories (SFHs) of Cao23 ELSBGs by SED fitting, dividing the SFHs into seven look back time bins with constant SFRs assumed for each bin. Our analysis indicates that high-mass (M∗ > 109.0M⊙) Cao23 ELSBGs assembled their mass earlier than their lower-mass counterparts, supporting a downsizing trend for LSBGs.

As one type of blue early-type galaxy, the evolutionary history and fate of star-forming lenticular galaxies (S0s) remain elusive. We selected 134 star-forming S0s from the Sloan Digital Sky Survey IV MaNGA survey and found that they have steep and warped size–mass relations, similar to quiescent S0s and red spirals, indicating that they may have similar gas dissipation scenarios. These galaxies have a higher central stellar mass surface density than normal blue spirals. The radial profiles of D _n 4000 and [Mgb/Fe] show that red spirals and quiescent S0s have similar old central populations and high [Mgb/Fe] values, suggesting rapid bulge formation, though red spirals exhibit a steeper gradient possibly due to residual star formation (SF) in outer regions. In contrast, star-forming S0s exhibit profiles between quiescent S0s/red spirals and normal blue spirals, with relatively flat D _n 4000 and [Mgb/Fe] gradients. More long-term SF history causes normal blue spirals to have very flat D _n 4000 and [Mgb/Fe] profiles, and the majority of them (79% ± 5%) have a Sérsic index of

We present the integral field spectroscopic observations of ionized gas (H α and [N II ]) using the PCWI, along with deep CO(2–1) observations by the ${}^{\unicode{x02035}}{\bar{{\rm{U}}}}^{\unicode{x02035}}\bar{{\rm{u}}}$ receiver on JCMT for AGC 102004. The velocity field of H α shows an anomalous distribution in the northwestern (NW) disk. The H α spectrum is well-fitted by two Gaussian components, and the weak Gaussian component is dominated by the anomalous H α in the NW disk. The Gaussian fit center of H α emission is offset by +24.2 km s ^−1 from the systemic velocity obtained from the H i emission. We derive the gas-phase metallicity, 12+log(O/H), using [N II ] λ 6583/H α ratio as a proxy. The mean value of 12+log(O/H) is 8.30 ± 0.19 over the whole galaxy. The metallicity in the outer disk is lower than the detection limit of 7.72, indicating the metallicity gradient exists in AGC 102004. We speculate a minor/mini-merger event could have happened to the NW disk. CO(2–1) emission has nondetection in AGC 102004, reaching a noise level of 0.33 mK smoothed to 30 km s ^−1 . The upper limit of molecular gas mass in AGC 102004 is 2.1 × 10 ^7 M _⊙ with X _CO = 3.02 × 10 ^20 cm ^−2 (K km s ^−1 ) ^−1 . The ${M}_{{{\rm{H}}}_{2}}$ / M ${}_{{\rm{H}}\,{\rm{I}}}^{{\rm{corr}}}$ of AGC 102004 is lower than 0.0037 and lower than that of normal galaxies.