HI-rich Starless Halos

Data tables accompanying Moreno et al. (2026). These data underlie the figures comparing FIREbox, NIVARIA-LG, and Recal-EAGLE starless halos to the observed Cloud-9 system.

Figure 1 — Halo Population Properties

Population-level properties for HI-rich starless halos selected from three cosmological simulations. Each row is one galaxy; columns give the base-10 logarithm of halo mass (M₂₀₀), total gas mass (M_gas), and neutral hydrogen mass (M_HI), all in solar masses.

corner_plot_bottom_panel_data.csv

log₁₀ M₂₀₀, M_gas, M_HI [M☉] for FIREbox, NIVARIA-LG, and Recal-EAGLE (42 rows)

Figure 2 — Gas Phase Diagrams

Temperature–density phase diagram data for all four FIREbox halos pooled together, compared to NIVARIA-LG and Recal-EAGLE. The IQR bands show the 25th–75th percentile temperature in 0.3 dex hydrogen number density bins. The ratio panel (bottom) shows log₁₀(T / T_BL+2017), where T_BL+2017 is the BL+2017 photoionization equilibrium reference curve.

phase_BL2017.csv

BL+2017 reference curve: n_H [cm⁻³], T [K] (31 rows)

phase_recal_eagle.csv

Recal-EAGLE IQR band: upper and lower curves digitized from BL+2026

phase_firebox.csv

FIREbox IQR band: n_H, T₂₅, T₇₅ on 0.3 dex grid

phase_nivaria.csv

NIVARIA-LG IQR band: n_H, T₂₅, T₇₅ on 0.3 dex grid

phase_ratio.csv

Bottom panel: log₁₀(T/T_BL+2017) IQR for all three simulations

Figure 3 — N_HI Column Density Profiles

Neutral hydrogen column density profiles from the combined profiles figure. All radii are projected radii in arcminutes, assuming a distance to Cloud-9 of 4.41 Mpc (Anand et al. 2025). N_HI is in cm⁻². Convolved profiles use the FAST beam (σ = 1.23 arcmin) or half that (σ = 0.615 arcmin). Shape residuals in the bottom panel are log₁₀(N_HI^conv / N_HI^CL9), normalized to zero at the innermost radius.

profiles_cloud9.csv

Cloud-9 observed profile: radius, N_HI, lower & upper 1σ bounds (15 rows)

profiles_nivaria.csv

NIVARIA-LG intrinsic + FAST-convolved profiles (12 rows)

profiles_firebox.csv

FIREbox 4 halos — intrinsic + convolved profiles, one row per radial bin

profiles_residuals.csv

Shape residuals (bottom panel) for all halos + NIVARIA-LG, evaluated at Cloud-9 radii