Although thick disk is a structure prevalent in local disk galaxies and alsopresent in our home Galaxy, its formation and evolution is still unclear.Whether the thick disk is born thick and/or gradually heated to be thick afterformation is under debate. To disentangle these two scenarios, one effectiveapproach is to inspect the thickness of young disk galaxies in the highredshift Universe. In this work we study the vertical structure of 191 edge-ongalaxies spanning redshift from 0.2 to 5 using JWST NIRCAM imagingobservations. For each galaxy, we retrieve the vertical surface brightnessprofile at 1 ${R_e}$ and fit a sech$^2$ function that has been convolved withthe line spread function. The obtained scale height of galaxies at $z>1.5$ showno clear dependence on redshift, with a median value in remarkable agreementwith that of the Milky Way's thick disk. This suggests that local thick disksare already thick when they were formed in the early times and secular heatingis unlikely the main driver of thick disk formation. For galaxies at $z<1.5$,however, the disk scale height decreases systematically towards lower redshift,with low-redshift galaxies having comparable scale height with that of theMilky Way's thin disk. This cosmic evolution of disk thickness favors anupside-down formation scenario of galaxy disks.

We probe the neutral circumgalactic medium (CGM) along the major axes ofNGC891 and NGC4565 in 21-cm emission out to $\gtrsim 100$kpc using the GreenBank Telescope (GBT), extending our previous minor axes observations. Weachieve an unprecedented $5\sigma$ sensitivity of $6.1\times 10^{16}$ cm$^{-2}$per 20 km s$^{-1}$ velocity channel. We detect HI with diverse spectral shapes,velocity widths, and column densities. We compare our detections to theinterferometric maps from the Westerbork Synthesis Radio Telescope (WSRT)obtained as part of the HALOGAS survey. At small impact parameters, $> 31-43\%$of the emission detected by the GBT cannot be explained by emission seen in theWSRT maps, and it increases to $> 64-73\%$ at large impact parameters. Thisimplies the presence of diffuse circumgalactic HI. The mass ratio between HI inthe CGM and HI in the disk is an order of magnitude larger than previousestimates based on shallow GBT mapping. The diffuse HI along the major axespointings is corotating with the HI disk. The velocity along the minor axespointings is consistent with an inflow and/or fountain in NGC891 and aninflow/outflow in NGC4565. Including the circumgalactic HI, the depletion timeand the accretion rate of NGC4565 are sufficient to sustain its star formation.In NGC891, most of the required accreting material is still missing.

We present the discovery of a new H I structure in the NGC 7194 group fromthe observations using the Karl G. Jansky Very Large Array. NGC 7194 group is anearby (z ~ 0.027) small galaxy group with five quiescent members. Theobservations reveal a 200 kpc-long H I plume that spans the entire group with atotal mass of M$_{HI}$ = 3.4 x 10$^{10}$ M$_{\odot}$. The line-of-sightvelocity of the H I gas gradually increases from south (7200 km s$^{-1}$) tonorth (8200 km $^{-1}$), and the local velocity dispersion is up to 70 kms$^{-1}$. The structure is not spatially coincident with any member galaxiesbut it shows close associations with a number of blue star-forming knots.Intragroup H I gas is not rare, but this particular structure is still one ofthe unusual cases in the sense that it does not show any clear connection withsizable galaxies in the group. We discuss the potential origins of thislarge-scale H I gas in the NGC 7194 group and its relation with theintergalactic star-forming knots. We propose that this HI feature could haveoriginated from tidal interactions among group members or the infall of alate-type galaxy into the group. Alternatively, it might be leftover gas fromflyby intruders.