  We report the discovery of two short-period massive giant planets from NASA's
Transiting Exoplanet Survey Satellite (TESS). Both systems, TOI-558 (TIC
207110080) and TOI-559 (TIC 209459275), were identified from the 30-minute
cadence Full Frame Images and confirmed using ground-based photometric and
spectroscopic follow-up observations from TESS's Follow-up Observing Program
Working Group. We find that TOI-558 b, which transits an F-dwarf
($M_{*}=1.349^{+0.064}_{-0.065}\ M_{\odot}$, $R_{*}=1.496^{+0.042}_{-0.040}\
R_{\odot}$, $T_{eff}=6466^{+95}_{-93}\ K$, age $1.79^{+0.91}_{-0.73}\ Gyr$)
with an orbital period of 14.574 days, has a mass of $3.61\pm0.15\ M_{\rm J}$,
a radius of $1.086^{+0.041}_{-0.038}\ R_{\rm J}$, and an eccentric
(e=$0.300^{+0.022}_{-0.020}$) orbit. TOI-559 b transits a G-dwarf
($M_{*}=1.026\pm0.057\ M_{\odot}$, $R_{*}=1.233^{+0.028}_{-0.026}\ R_{\odot}$,
$T_{eff}=5925^{+85}_{-76}\ K$, age $6.8^{+2.5}_{-2.0}\ Gyr$) in an eccentric
(e=$0.151\pm0.011$) 6.984-day orbit with a mass of $6.01^{+0.24}_{-0.23}\
M_{\rm J}$ and a radius of $1.091^{+0.028}_{-0.025}\ R_{\rm J}$. Our
spectroscopic follow-up also reveals a long-term radial velocity trend for
TOI-559, indicating a long-period companion. The statistically significant
orbital eccentricity measured for each system suggests that these planets
migrated to their current location through dynamical interactions.
Interestingly, both planets are also massive ($>3\ M_{\rm J}$), adding to the
population of massive giant planets identified by TESS. Prompted by these new
detections of high-mass planets, we analyzed the known mass distribution of hot
and warm Jupiters but find no significant evidence for multiple populations.
TESS should provide a near magnitude-limited sample of transiting hot Jupiters,
allowing for future detailed population studies.
