The TolTEC Clouds to Cores Legacy Survey

Science Goal: The Clouds to Cores Survey will map the bulk of ten nearby giant molecular clouds, taking a census of cores in each and characterizing their spatial distribution, as well as measure their masses, sizes and other structural properties. We will leverage commensurate Spitzer and Herschel imaging of the young stars and diffuse gas in these clouds in order to see how the presence of stars or diffuse gas properties may correlate with core properties. Ultimately, we will construct core mass functions of various subsets of cores to test its potential universality, providing a strong new constraint for star formation models.

Depth Goal: We aim to detect cores down to M>0.11MSolar (S1.1~0.27 mJy rms.)

Areal Coverage: 44-88 sq. deg. depending on mapping speeds

Field Priority:

  • LST group 1: Orion-A, Perseus, Orion-B, Auriga-Cal, Mon R2
  • LST group 2: Cygnus-X, Aquila-S, Aquila-N,
  • LST group 3: Ophiuchus, CepOB3,

    • Why do a C2C Survey?

    The stellar IMF is the fundamental basis of many astrophysical phenomena, from the rate of star formation and supernova explosions in galaxies to the frequency of habitable planets around other stars. Despite much empirical characterization, theories for the origin of the IMF remain very poorly constrained. One current set of theories postulates that the distribution of stellar masses is inherited from the distribution of gas. With FWHM=5” resolution, TolTEC and LMT will resolve individual pre-stellar cores out to distances of 2 kpc, enabling core censuses for a substantial number of giant molecular clouds that can provide strong tests for these theories. The C2C survey will map ten such clouds in their entirety with sufficient depth to detect 0.11 Mʘ pre-stellar cores and sufficient completeness to characterize the CMF to <0.3 Mʘ. This massive core census in a wide variety of clouds will enable the detection of any environmental effects on the CMF turnoff mass and power law index, and will provide a strong statistical base for the first time to address fundamental questions such as: What is the origin of the stellar IMF? Is there an intimate link between the CMF and the IMF? Is the CMF universal?

    Herschel/SPIRE-derived column density (intensity) and temperature (color) map from Pokhrel et al. (2016).

    Simulated core mass function sensitivity for the integrated Clouds-to-Cores survey with core numbers scaled from AzTEC observations of the MonR2 cloud (Sokol et al. 2019). Error bands denote 3σ uncertainties in the recovered CMF for differently scaled IMF models and are dominated by Poisson statistics for this survey.