NASA/IPAC EXTRAGALACTIC DATABASE
Date and Time of the Query: 2019-08-17 T10:51:55 PDT
Help | Comment | NED Home

For refcode 2009A&A...494..539L:
Retrieve 28 NED objects in this reference.
Please click here for ADS abstract

NED Abstract

Copyright by European Southern Observatory (ESO). Reproduced by permission
2009A&A...494..539L The mass function of young star clusters in spiral galaxies Larsen, S. S. Abstract. Aims. The initial cluster mass function (ICMF) in spiral discs is constrained and compared with data for old globular clusters and young clusters in starbursts. Methods: For a given absolute magnitude, the cluster age distribution depends on the ICMF. Here, the behaviour of the median age-magnitude relation is analysed in detail for Schechter ICMFs with various cut-off masses, M_c. The calculated relations are compared with observations of the brightest clusters in spiral galaxies. Schechter functions are also fitted directly to observed mass functions (MFs). Results: A single Schechter ICMF with an M_c_ of a few times 10^5^ M_o_ can reproduce the observed ages and luminosities of the brightest (and 5th brightest) clusters in the spirals if disruption of optically visible clusters is dominated by relatively slow secular evolution. A Schechter function fit to the combined cluster MF for all spirals in the sample yields M_c_ = (2.1+/-0.4)x10^5^ M_o_. The MFs in cluster-poor and cluster-rich spirals are statistically indistinguishable. An M_c_ = 2.1x10^5^ M_o_ Schechter function also fits the MF of young clusters in the Large Magellanic Cloud. If the same ICMF applies in the Milky Way, a bound cluster with M > 10^5^ M_o_ will form about once every 10^7^ years, while an M > 10^6^ M_o_ cluster will form only once every 50 Gyr. Luminosity functions (LFs) of model cluster populations drawn from an M_c_ = 2.1x10^5^ M_o_ Schechter ICMF generally agree with LFs observed in spiral galaxies. Conclusions: The ICMF in present-day spiral discs can be modelled as a Schechter function with M_c_ ~ 2x10^5^ M_o_. However, the presence of significant numbers of M > 10^6^ M_o_ (and even M > 10^7^ M_o_) clusters in some starburst galaxies makes it unlikely that the M_c_ value derived for spirals is universal. In high-pressure environments, such as those created by complex gas kinematics and feedback in mergers, M_c_ can shift to higher masses than in quiescent discs. Key words: Galaxy: open clusters and associations: general, galaxies: star clusters, galaxies: spiral
Retrieve 28 NED objects in this reference.
Please click here for ADS abstract

Back to NED Home