CORRELATION BETWEEN INTERSTELLAR MAGNETIC-FIELDS AND STAR-FORMATION RATE

We examine the correlation behveen the star formation rate (SFR) and t he strength of mean interstellar magnetic fields, adopting some simple assumptions. According to the recent work by Vallee, the strength of an interstellar magnetic field (B) have only weak dependence on SFR, a nd he observationally obtained B proportional to SFR(0.13) However, ad opting two assumptions (the so-called Schmidt law and double equiparti tion of energy among three types of interstellar medium [ISM] [thermal gas: E(th), magnetic fields: E(mag), and nonthermal component: E(non) ]), we find that Vallee's observational result includes an important m eaning. According to our result, the correlation predicted by the doub le equipartition theory is represented by B proportional to SFR(1/2n) where n is defined by SFR proportional to rho(n). We note that Vallee adopts the data corresponding to the case of single equipartition (E(m ag) = E(non)) and n = 1.3. Then, B should have a stronger dependence o n SFR as far as our assumptions permit. This discrepancy suggests that the double equipartition model of ISM is not established ina galactic wide view (E(mag) not equal E(th)).