X- RAY EMISSION IN GREEN PEAS 3 Table 1. Host galaxy properties of green peas Object RA DEC Redshift SFR (M⊙ yr −1 ) 12+log(O/H) X-ray detection He II detection J173501.2+570308 263.76 57.05 0.091 14.04 8.26 True True J002101.0+005248 5.25 0.88 0.077 8.00 8.22 True True J084414.2+022620 131.06 2.44 0.066 5.06 8.10 True True J093813.5+542824 144.56 54.47 0.047 10.19 8.07 True True J080619.5+194927 121.58 19.82 0.102 13.56 8.27 True True J141059.2+430247 212.75 43.05 0.07 9.84 8.29 True True J140956.6+545648 212.49 54.95 0.098 13.71 8.23 True True J162410.10-002202.5 246.04 -0.37 0.031 3.98 8.24 True True SHOC 486 22.02 -1.18 0.027 2.77 8.07 True True J121903.98+152608.5 184.77 15.44 0.196 12.96 7.87 False True J101629.88+073404.9 154.12 7.57 0.183 16.94 8.18 False False J164235.52+422349.7 250.65 42.40 0.151 16.48 8.24 False False J104645.75+302330.9 161.69 30.39 0.127 8.58 8.32 False False J121932.22+213324.9 184.88 21.56 0.141 19.06 8.21 False True J014721.7-091646 26.84 -9.28 0.136 4.99 8.19 False False J144231.37-020952.0 220.63 -2.16 0.294 21.23 8.00 False False J150934.17+373146.1 227.39 37.53 0.033 1.77 7.85 False True J160627.53+135547.8 241.61 13.93 0.107 9.28 8.20 False True J101526.38+305451.9 153.86 30.91 0.092 6.09 8.26 False False J031023.94-083432.8 47.6 -8.58 0.052 0.96 8.26 False False J092532.36+140313.1 141.38 14.05 0.301 23.8 8.06 False False J235604.67-85423.4 359.02 -8.91 0.169 9.06 8.26 False False J094244.23+411019.3 145.68 41.17 0.046 2.56 7.94 False False J132916.55+170020.9 202.32 17.01 0.094 9.95 8.22 False True J155027.78+192058.7 237.62 19.35 0.212 20.76 8.27 False False J154748.99+22303.2 236.95 22.05 0.031 0.68 8.05 False False J140018.93+010453.8 210.08 1.08 0.121 11.78 8.08 False False J154543.55+085801.3 236.43 8.97 0.038 4.43 7.76 False True lent width emission lines, with either the equivalent width of [O III] 5007 ˚ A, EW 5007 > 300 ˚ A, or the equivalent width of the Balmer Hβ line EW Hβ > 100 ˚ A. Further details of the se- lection are given in Jiang et al. (2019). We cross matched this list with the Chandra Observations Catalog and the Chandra Source Catalog, Version 2.0 to identify green pea galaxies where we can study X-ray emission properties. We identified 29 green peas with CXO observations, including 7 that are detected in the Chandra Source Catalog. 2 additional sources were detected with X-ray emission over > 3σ confidence among the remaining 22 sources. 2.2. Optical Data: We used Sloan Digital Sky Survey optical spectra to mea- sure the flux and flux error of the He IIλ4686 line for the 29 sources in our sample. We considered He IIλ4686 as detected only when the signal-to-noise ratio, S/N He II > 3. Among the 9 X-ray-detected sources, 8 exhibited He IIλ4686λ4686 detection over 3σ confidence. Similarly, among the 20 X- ray non-detected sources, 9 displayed He IIλ4686 detections. One source hovered at a borderline S/N He II ∼ 2.99. How- ever, adopting a conservative stance, we opted to disregard this particular source due to its S/N < 3. Other emis- sion lines used in our analysis (e.g., Hα and [N II]; see sec- tion 3.2.2) are similarly measured from the SDSS spectra. 2.3. X-ray Data: For X-ray measurements, we used measurements from the Chandra Source Catalog, Version 2.0 for the seven sample objects contained in that catalog. We downloaded the data for the remaining 22 sources from the Chandra X-ray Cen- ter (CXC), and then reduced and analyzed using the Chandra Interactive Analysis of Observations (CIAO; v4.16) tools (Fr- uscione et al. 2006). Firstly, we utilized the CIAO task repro to reprocess the level-1 ACIS event file data. Then we used the task srcflux to estimate the source counts and fluxes in the