text: 418,102,1457535272678166528,60893773,James Bullock,"New paper led by @UCIPhysAstro PhD student @danphysic uses FIRE simulations to predict J-factors for DM-indirect detection @ Galactic Center ➡️Velocity-dependent p & d-wave annihilation amplified compared to dark-matter-only expectations @UCIrvineGD <LINK> <LINK> For p-wave annihilation ~(v/c)^2, standard expectation is these models not detectable because v&lt;&lt;c in Milky Way. We find signal is ~10 times higher than you'd expect from dark-matter-only =&gt; p-wave models w/ correct thermal abundance may be within the range of detection! <LINK> The reason for enhancement is that dark-matter particle velocities are significantly enhanced in the Galactic Center compared to dark-matter-only simulations - a result of galaxy formation <LINK> What fantastic work by Daniel McKeown @danphysic and wonderful collaborators @AstronoMerc_ @ZachHafen @MBKplus @AndrewWetzel @linoush95 @PFHopkins_Astro @AstroBananna - Congratulations! <LINK> @TillSawala @UCIPhysAstro @danphysic @UCIrvineGD For p & d-wave, yes. Dwarfs harder. Clusters easier though. @ProfTimTait @danphysic @AstronoMerc_ @ZachHafen @MBKplus @AndrewWetzel @linoush95 @PFHopkins_Astro @AstroBananna Yes! Simona was on @danphysic advancement so has a heads up!",https://arxiv.org/abs/2111.03076,"We use FIRE-2 zoom cosmological simulations of Milky Way size galaxy halos to calculate astrophysical J-factors for dark matter annihilation and indirect detection studies. In addition to velocity-independent (s-wave) annihilation cross sections $\sigma_v$, we also calculate effective J-factors for velocity-dependent models, where the annihilation cross section is either either p-wave ($\propto v^2/c^2$) or d-wave ($\propto v^4/c^4$). We use 12 pairs of simulations, each run with dark-matter-only (DMO) physics and FIRE-2 physics. We observe FIRE runs produce central dark matter velocity dispersions that are systematically larger than in DMO runs by factors of $\sim 2.5-4$. They also have a larger range of central ($\sim 400$ pc) dark matter densities than the DMO runs ($\rho_{\rm FIRE}/\rho_{\rm DMO} \simeq 0.5 - 3$) owing to the competing effects of baryonic contraction and feedback. At 3 degrees from the Galactic Center, FIRE J-factors are $5-50$ (p-wave) and $15-500$ (d-wave) times higher than in the DMO runs. The change in s-wave signal at 3 degrees is more modest and can be higher or lower ($\sim 0.3-6$), though the shape of the emission profile is flatter (less peaked towards the Galactic Center) and more circular on the sky in FIRE runs. Our results for s-wave are broadly consistent with the range of assumptions in most indirect detection studies. We observe p-wave J-factors that are significantly enhanced compared to most past estimates. We find that thermal models with p-wave annihilation may be within range of detection in the near future. ","Amplified J-factors in the Galactic Center for velocity-dependent