Using early data from the Dark Energy Spectroscopic Instrument (DESI) survey,we search for AGN signatures in 410,757 line-emitting galaxies. By employingthe BPT emission-line ratio diagnostic diagram, we identify AGN in75,928/296,261 ($\approx$25.6%) high-mass ($\log (M_{\star}/\rm M_{\odot}) >$9.5) and 2,444/114,496 ($\approx$2.1%) dwarf ($\log (M_{\star}/\rm M_{\odot})\leq$ 9.5) galaxies. Of these AGN candidates, 4,181 sources exhibit a broadH$\alpha$ component, allowing us to estimate their BH masses via virialtechniques. This study more than triples the census of dwarf AGN and doublesthe number of intermediate-mass black hole (IMBH; $M_{BH} \le 10^6~\rmM_{\odot}$) candidates, spanning a broad discovery space in stellar mass (7 $<\log (M_{\star}/M_{\odot}) <$ 12) and redshift (0.001 $< \rm z <$ 0.45). Theobserved AGN fraction in dwarf galaxies ($\approx$2.1%) is nearly four timeshigher than prior estimates, primarily due to DESI's smaller fiber size, whichenables the detection of lower luminosity dwarf AGN candidates. We also extendthe $M_{BH} - M_{\star}$ scaling relation down to $\log (M_{\star}/M_{\odot})\approx$ 8.5 and $\log (M_{BH}/\rm M_{\odot}) \approx$ 4.4, with our resultsaligning well with previous low-redshift studies. The large statistical sampleof dwarf AGN candidates from current and future DESI releases will beinvaluable for enhancing our understanding of galaxy evolution at the low-massend of the galaxy mass function.

Context. Giant Low Surface Brightness galaxies, such as Malin 1, hostextended stellar and gaseous disks exceeding 100 kpc in radius. Their formationand evolution remain debated, with interactions with satellite galaxies andaccretion streams proposed as key contributors. Malin 1 has multiplesatellites, including Malin 1A, Malin 1B, and the newly reported Malin 1C,along with eM1 at 350 kpc. Additionally, it exhibits two giant stellar streams,the largest extending 200 kpc, likely linked to past interactions. Aims. We investigate the orbital dynamics of Malin 1's satellites and theirrelationship with the observed stellar streams, testing their consistency withdifferent formation scenarios. Methods. We constructed gravitational potentials using optical and H Irotation curve data, using stellar, gaseous, and dark matter components. Weexplored a wide parameter space to see if the candidate progenitors of thestellar streams could have originated from past interactions, testing both NFWand isothermal halo profiles. Results. Among ten explored scenarios, seven produced bound orbitalsolutions. The isothermal halo model, with a virial mass of 3.8 x 10^12 solarmasses and a virial radius of approximately 323 kpc, favors bound satelliteorbits more than the NFW model (1.7 x 10^12 solar masses). We find that eM1probably had a pericenter passage 1.3 Gyr ago, Malin 1A around 1.4 Gyr ago, andMalin 1B's leading arm may be experiencing one now. Malin 1C displays bothleading and trailing arms. Furthermore, we identify three unbound orbitalsolutions that could link eM1, Malin 1A, or Malin 1B to the streams. Conclusions. The alignment of satellites and streams supports the idea thatpast interactions contributed to Malin 1's morphology, enriched its gasreservoir, and influenced the development of its extended disk, providinginsights into the evolution of gLSBGs.

Using spatially resolved spectroscopic data from the MaNGA sample, weinvestigate the parameters influencing the radial gradients of gas-phasemetallicity ($\nabla\log(\mathrm{O/H})$), to determine whether disk formationis primarily driven by coplanar gas inflow or by the independent evolution ofdistinct regions within the disk. Our results show that $\nabla\log(\mathrm{O/H})$ strongly correlates with local gas-phase metallicity at agiven stellar mass, with steeper gradients observed in metal-poorer disks. Thistrend supports the coplanar gas inflow scenario, wherein the gas isprogressively enriched by in situ star formation as it flows inward. Incontrast, the radial gradient of stellar mass surface density shows very weakcorrelations with $\nabla \log(\mathrm{O/H})$, which is inconsistent with theindependent evolution mode, where gas inflow, star formation, and metalenrichment occur independently within each annulus of the disk. Furthermore, wefind that $\nabla \log(\mathrm{O/H})$ is also closely correlated with anindicator of local gas turbulence $\sigma_{\mathrm{gas}}/R_{\mathrm{e}}$,highlighting the competing roles of turbulence and coplanar inflow in shapingmetallicity gradients. Our results provide indirect observational evidencesupporting coplanar gas inflow as the driving mechanism for disk evolution.