The luminosity function of galactic ultra-compact HII regions and the IMF for massive stars

Details The luminosity function of galactic ultra-compact HII regions and the IMF for massive stars The luminosity function of galactic ultra-compact HII regions and the IMF for massive stars

1999-12-20

arxiv.org/abs/astro-ph/9912430v1

Astron.Astrophys.358:514-520,2000

Astronomy and Astrophysics

Astrophysics

accepted for publication in A&A

Scientific paper

The population of newly formed massive stars, while still embedded in their parent molecular clouds, is studied on the galactic disk scale. We analyse the luminosity function of IRAS point-like sources, with far-infrared (FIR) colours of ultra-compact HII regions, that have been detected in the CS(2-1) line - a tracer of high density molecular gas. The FIR luminosities of 555 massive star forming regions (MSFRs), 413 of which lie within the solar circle, are inferred from their fluxes in the four IRAS bands and from their kinematic distances, derived using the CS(2-1) velocity profiles. The luminosity function (LF) for the UCHII region candidates shows a peak well above the completeness limit, and is different within and outside the solar circle (96% confidence level). While within the solar circle the LF has a maximum for 2E5 Lo, outside the solar circle the maximum is at 5E4 Lo. We model the LF using three free parameters: -alpha, the exponent for the initial mass function (IMF) expressed in log(M/Mo); -beta, the exponent for a power law distribution in N*, the number of stars per MSFR; and N*max, an upper limit for N*. While alpha has a value of \~ 2.0 throughout the Galaxy, beta changes from ~ 0.5 inside the solar circle to \~ 0.7 outside, with a maximum for the number of stars per MSFR of ~650 and \~450 (with 1

Affiliated with

Also associated with

No associations

Rating

The luminosity function of galactic ultra-compact HII regions and the IMF for massive stars does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with The luminosity function of galactic ultra-compact HII regions and the IMF for massive stars, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The luminosity function of galactic ultra-compact HII regions and the IMF for massive stars will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-43743