Context : First Hydrostatic Cores represent a theoretically predicted intermediate evolutionary link between the prestellar and protostellar phases .
Studying observational characteristics of first core candidates is therefore vital for probing and understanding the earliest phases of star formation .

Aims : We aim to determine the dynamical state of the First Hydrostatic Core candidate Cha-MMS1 .

Methods : We observed Cha-MMS1 in various molecular transitions with the APEX and Mopra telescopes .
Continuum data retrieved from the Spitzer Heritage Archive were used to estimate the internal luminosity of the source .
The molecular emission was modeled with a radiative transfer code to derive constraints on the kinematics of the envelope , which were then compared to predictions of magneto-hydrodynamic simulations .

Results : We derive an internal luminosity of 0.08 L _ { \odot } – 0.18 L _ { \odot } for Cha-MMS1 .
An average velocity gradient of 3.1 \pm 0.1 km s ^ { -1 } pc ^ { -1 } over \sim 0.08 pc is found perpendicular to the filament in which Cha-MMS1 is embedded .
The gradient is flatter in the outer parts and , surprisingly , also at the innermost \sim 2000 AU to 4000 AU .
The former features are consistent with solid-body rotation beyond 4000 AU and slower , differential rotation beyond 8000 AU , but the origin of the flatter gradient in the innermost parts is unclear .
The classical infall signature is detected in HCO ^ { + } 3–2 and CS 2–1 .
The radiative transfer modeling indicates a uniform infall velocity in the outer parts of the envelope .
In the inner parts ( at most 9000 AU ) , an infall velocity field scaling with r ^ { -0.5 } is consistent with the data but the shape of the profile is less well constrained and the velocity could also decrease toward the center .
The infall velocities are subsonic to transonic , 0.1 km s ^ { -1 } – 0.2 km s ^ { -1 } at r \geq 3300 AU , and subsonic to supersonic , 0.04 km s ^ { -1 } – 0.6 km s ^ { -1 } at r \leq 3300 AU .
Both the internal luminosity of Cha-MMS1 and the infall velocity field in its envelope are consistent with predictions of MHD simulations for the first core phase .
There is no evidence for a fast , large-scale outflow stemming from Cha-MMS1 but excess emission from the high-density tracers CS 5–4 , CO 6–5 , and CO 7–6 suggests the presence of higher-velocity material at the inner core .

Conclusions : Its internal luminosity excludes Cha-MMS1 being a prestellar core .
The kinematical properties of its envelope are consistent with Cha-MMS1 being a first hydrostatic core candidate or a very young Class 0 protostar .