Abstract

A new solution is presented for the puzzling, observed universality of the exponential luminosity profiles, perpendicular to the disk plane of spiral and lenticular galaxies. It is shown that such exponential z-profiles result naturally from gaseous protodisks which settle into isothermal equilibrium prior to star formation. Subsequent cooling leads to a gravitational contraction of the gas towards the equatorial plane and to a stellar exponential z-profile if the star formation rate is assumed to be comparable to the cooling rate of the gas. The final stellar scale height depends only on the initial gas temperature and local surface density. This model therefore provides a new method to investigate the early energetic state of galactic protodisks with measured scale heights and surface densities along the disk plane.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.