Google's Pixel 3a and 3a XL were only released today, but already factory images are available for download. Odds are prospective customers don't have either of the new mid-range phones just yet, but if you're the sort to tear into images looking for titillating tidbits or a developer looking to get an early edge on rooting or ROMing, they're free for the taking.
Each phone — labeled by the codename Sargo for the Pixel 3a and Bonito for the Pixel 3a XL — comes with two downloads featuring slightly different build numbers: PD2A.190115.029 and PD2A.190115.032. Both are interestingly only for the March security patch level. It's possible (if not likely) that the two images could be targeting or excluding support for specific carriers, but they aren't labeled as such.
If, somehow, you do have a device on-hand to flash these factory images and you decide to, remember that you'll need to unlock your bootloader first.
- Pixel Factory Images