On the star formation rate – brightest cluster relation: estimating the peak star formation rate in post-merger galaxies

By N. Bastian. 2008

166 citations recorded by the source corpus.

We further the recent discussion on the relation between the star formation rate (SFR) of a galaxy and the luminosity of its brightest star cluster (SFR versus M V brightest ). We first show that the observed trend of SFR versus M V brightest is due to the brightest cluster in a galaxy being preferentially young (≤15 Myr - for a constant SFR) and hence a good tracer of the current SFR, although we give notable exceptions to this rule. Archival Hubble Space Telescope (HST) imaging of high-SFR galaxies, as well as additional galaxies/clusters from the literature, is used to further confirm the observed trend. Using a series of Monte Carlo simulations, we show that a pure power-law mass function with index a = 2 is ruled out by the current data. Instead, we find that a Schechter function (i.e. a power law with an exponential truncation at the high-mass end) provides an excellent fit to the data. Additionally, these simulations show that bound cluster formation (in M ⊙ yr -1 ) represents only ∼8±3 per cent of the total star formation within a galaxy, independent of the SFR. From this, we conclude that there is only a single mode of cluster formation which operates over at least 6 orders of magnitude in the SFR. We provide a simple model of star/cluster formation feedback within dwarf galaxies (and star-forming complexes within spirals) which highlights the strong impact that a massive cluster can have on its surroundings. Using this relation, we can extrapolate backwards in time in order to estimate the peak SFR of major merger galaxies, such as NGC 7252,1316 and 3610. The derived SFRs for these galaxies are between a few hundred and a few thousand solar masses per year. The inferred far-infrared luminosity of the galaxies, from the extrapolated SFR, places them well within the range of ultraluminous infrared galaxies (ULIRGs) and for NGC 7252 within the hyperluminous infrared galaxy (HLIRG) regime. Thus, we provide evidence that these post-merger galaxies passed through a ULIRG/HLIRG phase and are now evolving passively. Using the current and extrapolated past SFR of NGC 34, we infer that the ULIRG phase of this galaxy has lasted for at least 150 Myr.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/53dcae24cb7543c9cbc60d01890d57239406c2ae

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Citations in the corpus

Young Massive Star Clusters (2010, methodology): “More recently, Bastian (2008) has used the Lmax–SFR relation to derive a cluster formation efficiency of ∼ 8%.”
The formation and assembly history of the Milky Way revealed by its globular cluster population (2018, methodology): “MNRAS 000, 1–22 (2018) star formation occurring in bound clusters (Bastian 2008; Goddard et al. 2010, the cluster formation efficiency) is environmentally dependent according to the model of Kruijssen (2012).”
Probing the role of the galactic environment in the formation of stellar clusters, using M83 as a test bench (2015, background): “Widely used in the cluster literature, the brightest cluster luminosity versus the SFR of the galaxy is a relation dominated by the size-of-sample effect (Larsen 2002; Bastian 2008).”
The big problems in star formation: The star formation rate, stellar clustering, and the initial mass function (2014, background): “Some authors also report a non-powerlaw cutoff at the highest masses (Bastian 2008; Larsen 2009; Bastian et al. 2012a), though the reality of this feature is disputed (Fall & Chandar 2012).”
THE ANTENNAE GALAXIES (NGC 4038/4039) REVISITED: ADVANCED CAMERA FOR SURVEYS AND NICMOS OBSERVATIONS OF A PROTOTYPICAL MERGER (2010, background): “We have interpreted this steep decline – 22 – as being primarily due to the disruption, rather than the formation, of clusters (see also FCW05; WCF07; FCW09).”
Globular cluster systems in nearby dwarf galaxies – III. Formation efficiencies of old globular clusters (2010, background): “…and star-cluster formation efficiencies generally appear to be closely correlated as it is observed that the ratio of cluster to star formation rates (SFR) is nearly constant (e.g. Lada & Lada 2003; Lamers & Gieles 2008; Gieles & Bastian 2008) and independent of the present-day SFR (Bastian 2008).”
On the fraction of star formation occurring in bound stellar clusters (2012, background): “The fraction of star formation occurring in bound stellar clusters is often quantified as the cluster formation efficiency (CFE or ; see e.g. Bastian 2008; Goddard, Bastian & Kennicutt 2010; Adamo, Östlin & Zackrisson 2011; Silva-Villa & Larsen 2011).”
Globular clusters as the relics of regular star formation in ‘normal’ high-redshift galaxies (2015, background): “(ii) Only some fraction of all star formation occurs in bound stellar clusters (Lada & Lada 2003), which is referred to as the the cluster formation efficiency (CFE orΓ, Bastian 2008).”
The mass function of young star clusters in spiral galaxies (2008, background): “If a peak star formation rate of ∼1000 M yr−1 (Bastian 2008) were turned completely into clusters, the number of clusters with M > 107 M formed would be less than 5 × 10−5 Myr−1 for Mc = 106 M .”