We perform local excitation calculations to obtain line opacities and emissivity ratios and compare them with observed properties of H , HeI , OI , CaII , and NaI lines to determine the requisite conditions of density , temperature , and photon ionization rate .
We find that UV photoionization is the most probable excitation mechanism for generating the HeI \lambda 10830 opacities that produce all the associated absorption features .
We also calculate the specific line flux at an observed velocity of v _ { obs } = \pm 150 ~ { } km~ { } s ^ { -1 } for both radial wind and infall models .
All the model results , together with observed correlations between absorption and emission features and between narrow and broad emission components , are used to deduce the origins of the strong H , HeI , and CaII broad line emission .
We conclude that the first two arise primarily in a radial outflow that is highly clumpy .
The bulk of the wind volume is filled by gas at a density \sim 10 ^ { 9 } ~ { } cm ^ { -3 } and optically thick to HeI \lambda 10830 and H \alpha , but optically thin to HeI \lambda 5876 , Pa \gamma , and the CaII infrared triplet .
The optically thick HeI \lambda 5876 emission occur mostly in regions of density \geq 10 ^ { 11 } ~ { } cm ^ { -3 } and temperature \geq 1.5 \times 10 ^ { 4 } ~ { } K , while the optically thick H \alpha and Pa \gamma emission occur mostly in regions of density around 10 ^ { 11 } ~ { } cm ^ { -3 } and temperature between 8750 and 1.25 \times 10 ^ { 4 } ~ { } K .
In producing the observed line fluxes at a given v _ { obs } the covering factor of these emission clumps is sufficiently small to not incur significant absorption of the stellar and veiling continua in either HeI or H lines .
The strong CaII broad line emission likely arise in both the magnetospheric accretion flow and the disk boundary layer where the gases dissipate part of their rotational energies before infalling along magnetic field lines .
The needed density and temperature are \sim 10 ^ { 12 } ~ { } cm ^ { -3 } and \leq 7500 ~ { } K respectively .