Detection of $δ$ Scuti pulsators in the eclipsing binaries observed by TESS

Abstract: Based on 2-minute cadence TESS data from sectors 1-50, we report the results of the systematic extraction of $\delta$ Scuti-type pulsations in the 6431 eclipsing binaries with orbital periods shorter than 13 days. A total number of 242 pulsators were found in those systems, including 143 new discoveries. We examined their pulsation properties based on the H-R diagram and the relationships between the dominant pulsation period $P_{\rm dom}$, orbital period $P_{\rm orb}$, and effective temperature $T_{\rm eff}$. As a consequence, 216 targets are likely $\delta$ Scuti stars (123 new), 11 likely $\gamma$ Doradus-$\delta$ Scuti hybrid stars (8 new), 5 likely $\beta$ Cephei stars (4 new), 4 likely $\delta$ Scuti-$\gamma$ Doradus hybrid stars (3 new), 3 likely Maia stars (3 new), 2 likely pulsating red giants (1 new), and a new unclassified star. As for the 6 new $\delta$ Scuti pulsators in eclipsing binaries with $P_{\rm orb}$ $<$ 0.65 days, we found that 3 of them significantly exceed the upper limits of the $P_{\rm dom}$/$P_{\rm orb}$ ratio. This may indicate that $P_{\rm dom}$ and $P_{\rm orb}$ are uncorrelated for them. Finally, we statistically analyzed the dominant pulsation periods of the 216 $\delta$ Scuti stars in eclipsing binaries. Those stars concentrate around 225 $\mu$Hz and the proportion of stars in the high-frequency region is significantly higher than that of single stars, which could be ascribed to the mass transfer process.