Electron fraction and cosmic ray ionization rates in star-forming regions are important quantities for proper astrochemical modeling and properly quantifying nonideal MHD terms. However, these are difficult quantities to estimate. We combined observations of the nearby NGC 1333 star-forming region carried out with NOEMA interferometer and 30m single dish to generate high spatial dynamic range maps of different molecular transitions. We use the ratio of DCO+ and H13CO+ (in addition to complementary data) to estimate the electron fraction and cosmic ray ionization rate maps.
We derive the first electron fraction and cosmic rate ionization rate maps in a star-forming region. The maps present clear evidence for interaction with a single nearby bubble, as previously suggested. We find high values of the electron fraction, as well as strong evidence for locally generated cosmic rays. We show how a higher cosmic ray ionization rate (compared to the canonical value of 10^{-17} s-1) is found in the region, and it is generated by the accreting young stellar objects. Moreover, the electron fraction is affected by the depletion of metals and the higher cosmic rate in these regions.
We will discuss further implications and opportunities to expand these studies.