Modeling the Hα and He 10830 Transmission Spectrum of WASP-52b

Escaping atmosphere has been detected by the excess absorption of Ly$\alpha$, H$\alpha$ and He triplet (10830$\rm\AA$) lines. Simultaneously modeling 10830 lines can provide useful constraints about exoplanetary atmosphere. In this paper, we use a hydrodynamic model combined with non-local thermodynamic new Monte Carlo simulation to obtain H(2) He(2$^3$S) populations. The simulations Ly$\alpha$ radiative transfer are performed assumptions spherical stellar radiation planetary atmosphere, for first time, calculate mean intensity distribution inside necessary in estimating population. We transmission spectra simultaneously hot Jupiter WASP-52b. find that models many different H/He ratios reproduce observations well if host star (1) high X-ray/extreme ultraviolet (XUV) flux ($F_{\rm XUV}$) relatively low X-ray fraction XUV ($\beta_m$), or (2) $F_{\rm XUV}$ $\beta_m$. $\rm\AA$ suggest ratio ($\sim$ 98/2) is required fit observation. both confine be 0.5 times fiducial value $\beta_m$ have around 0.3. also hydrogen helium originate from escaping mass-loss rate 2.8$\times 10^{11}$ g s$^{-1}$.