Star Forming Dense Cores: Properties from NH3 maps and a First Hydrostatic Core candidate, Jaime Pineda (CfA - Harvard)

Low-mass stars are formed in the densest and coldest regions inside Molecular Clouds called "Dense Cores." These dense cores present very low levels of turbulence (subsonic) while the surrounding lower density material shows supersonic turbulence (Mach>3). However, this transition in the level of turbulence has never been directly observed in the same tracer. I will present the results of mapping four regions within the Perseus MC in NH3 using the GBT. These data allow us to study the spatial properties of dense cores in detail, including the transition in turbulence.

Also, in one of the regions mapped in NH3 we identify a dense core that appear starless even in Spitzer wavelengths but with a high-level of concentration in the column density (probed by the dust continuum emission). This core would allow us to study the early stages of collapse. I will present the results of interferometric observations towards this core which reveal a central source. We constrain the possible scenarios to explain these observations using a simultaneous fit of the broadband SED and visibilities. We will show that this central source is the best candidate to date for a "First Hydrostatic Core."