Resumen

PARRAVANO, A; MCKEE, C.F  y  HOLLENBACH, D.J. The stellar initial mass function and star formation in the galaxy. Rev. mex. fis. [online]. 2006, vol.52, suppl.3, pp.1-4. ISSN 0035-001X.

We use observational constraints on the galactic ionizing photon production, the surface mass distribution of field M dwarfs, and the mass distribution of brown dwarfs in clusters to produce an effective galactic initial mass function (IMF). We assume that the IMF can be expressed as the product of a smooth function of mass m (in units of M_Θ),ψ (m), and a time dependent rate. We express the star formation rate per unit area per unit logarithmic mass interval as /[dA dln m] = [l - exp - ]; for (m < m_u ), with = 0.8 (the asymptotic low-mass slope inferred from the mass distribution in young clusters at sub-stellar masses), Γ = 1.35 (the negative of the high-mass slope), m_ch = 0.24 (producing a maximum at m_max~ m_ch), and m_u = 120. For a disk age of 11 Gyr, the average value of the star formation rate per unit logarithmic mass interval at 1 M_Θ at the solar circle is 620 kpc^-2 Myr^-1, and the ratio of the present to the mean SFR is b (t₀ ) = 1.085, where t₀ is the age of the disk.

Palabras llave : Stars; formation; stars; mass function; ISM; evolution.