Panchromatic Hubble Andromeda Treasury. XVIII. The High-mass Truncation of the Star Cluster Mass Function

Johnson, L. Clifton; Seth, Anil; Dalcanton, Julianne J.; Beerman, Lori C.; Fouesneau, M.; Weisz, Daniel R.; Bell, Timothy A.; Dolphin, Andrew E.; Sandström, Karin; Williams, Benjamin F.

doi:10.3847/1538-4357/aa6a1f

Cited by 104 publications

(207 citation statements)

References 94 publications

Supporting

Mentioning

175

Contrasting

Unclassified

Order By: Relevance

“…shear), the maximum cluster mass is not limited by shear, but by feedback disrupting a collapsing cloud before it has coalesced altogether. This updated model yields excellent agreement with observations of clouds, clumps, and clusters from the local Universe out to high redshift, including the lowest maximum cluster mass observed to date (M c = 8 × 10 3 M ⊙ in M31, Johnson et al 2017). Most importantly for the present work, Reina-Campos & Kruijssen (2017) demonstrated that the high-pressure conditions of globular cluster formation (almost) entirely correspond to the shear-limited regime.…”

Section: The Environmental Dependence Of the Maximum Cluster Masssupporting

confidence: 69%

“…There is a range of observational evidence showing that the cluster mass function has an exponential truncation at the highmass end, both for young clusters (e.g. Gieles et al 2006a;Larsen 2009;Portegies Zwart et al 2010;Johnson et al 2017) and globular clusters (e.g. Fall & Zhang 2001;Jordán et al 2007;Kruijssen & Portegies Zwart 2009).…”

Section: The Environmental Dependence Of the Maximum Cluster Massmentioning

confidence: 99%

See 1 more Smart Citation

The difference in metallicity distribution functions of halo stars and globular clusters as a function of galaxy type

Lamers

Kruijssen

Bastian

et al. 2017

A&A

View full text Add to dashboard Cite

Context. Observations of globular clusters (GCs) and field stars in the halos of the giant elliptical galaxy Cen A and the spiral galaxy M31 show a large range of cluster-to-star number ratios (or 'specific frequencies'). The cluster-to-star ratio decreases with increasing metallicity by over a factor of 100-1000, at all galactocentric radii and with a slope that does not seem to depend on radius. In dwarf galaxies, the GCs are also more metal-poor than the field stars on average. These observations indicate a strong dependence of either the cluster formation efficiency and/or the cluster destruction rate on metallicity and environment. Aims. We aim to explain the observed trends by considering the various effects that influence the cluster-to-star ratio as a function of metallicity, environment and cosmological history. Methods. We discuss the following effects that may influence the observed cluster-to-star ratio: (a) the formation efficiency of GCs; (b) the destruction of embedded GCs by gas expulsion; (c) the maximum masses of GCs; (d) the destruction of GCs by tidal stripping, dynamical friction, and tidal shocks as a function of environment; (e) the hierarchical assembly of GC systems during galaxy formation and the dependence on metallicity. Results. We show that both the cluster formation efficiency and the maximum cluster mass increase with metallicity, so they cannot explain the observed trend. Destruction of GCs by tidal stripping and dynamical friction destroy clusters mostly within the inner few kpc, whereas the cluster-to-star ratio trend is observed over a much larger range of galactocentric radii. We show that cluster destruction by tidal shocks from giant molecular clouds in the high-density formation environments of GCs becomes increasingly efficient towards high galaxy masses and, hence, towards high metallicities. The predicted cluster-to-star ratio decreases by a factor 100-1000 towards high metallicities and should only weakly depend on galactocentric radius due to orbital mixing during hierarchical galaxy merging, consistent with the observations. Conclusions. The observed, strong dependence of the cluster-to-star ratio on metallicity and the independence of its slope on galactocentric radius can be explained by cluster destruction and hierarchical galaxy growth. During galaxy assembly, GC metallicities remain a good tracer of the host galaxy masses in which the GCs formed and experienced most of their destruction. As a result, we find that the metallicity-dependence of the cluster-to-star ratio does not reflect a GC formation efficiency, but a survival fraction.

show abstract

Section: The Environmental Dependence Of the Maximum Cluster Masssupporting

confidence: 69%

Section: The Environmental Dependence Of the Maximum Cluster Massmentioning

confidence: 99%

The difference in metallicity distribution functions of halo stars and globular clusters as a function of galaxy type

Lamers

Kruijssen

Bastian

et al. 2017

A&A

View full text Add to dashboard Cite

show abstract

“…This is about an order of magnitude lower than the Σ SFR values typical of normal disc galaxies in the Local Universe (Kennicutt 1998). From the relation in Johnson et al (2017), this Σ SFR would correspond to a truncation mass of M c 4000 M , which would naturally explain why Fornax did not form any massive clusters for most of its lifetime.…”

Section: Metallicitiesmentioning

confidence: 85%

“…Using the relation in Johnson et al (2017), this gives a truncation mass of M c = 1.3 × 10 5 M , suggesting that some relatively massive clusters might have formed in NGC 147 during this epoch. Given that there are few, if any, GCs associated with the metal-rich field stars in NGC 147, cluster disruption may indeed have played a more important role in NGC 147.…”

Section: Metallicitiesmentioning

confidence: 99%

Detailed abundance analysis of globular clusters in the Local Group

Larsen

Brodie

Wasserman

et al. 2018

A&A

View full text Add to dashboard Cite

Context. Globular clusters (GCs) are emerging as powerful tracers of the chemical composition of extragalactic stellar populations. Aims. We present new abundance measurements for eleven GCs in the Local Group galaxies NGC 147, NGC 6822, and Messier 33. These are combined with previously published observations of four GCs in the Fornax and WLM galaxies. Methods. The abundances were determined from analysis of integrated-light spectra, obtained with the HIRES spectrograph on the Keck I telescope and with UVES on the VLT. We used our analysis technique that has been developed for this purpose and tested on Milky Way GCs. Results. We find that the clusters with [Fe/H] < −1.5 are all α-enhanced at about the same level as Milky Way GCs. Their Na abundances are also generally enhanced relative to Milky Way halo stars, suggesting that these extragalactic GCs resemble their Milky Way counterparts in containing significant fractions of Na-rich stars. For [Fe/H] > −1.5, the GCs in M33 are also α-enhanced, while the GCs that belong to dwarfs (NGC 6822 SC7 and Fornax 4) have closer to Solar-scaled α-element abundances. The abundance patterns in SC7 are remarkably similar to those in the Galactic GC Ruprecht 106, including significantly sub-solar [Na/Fe] and [Ni/Fe] ratios. In NGC 147, the GCs with [Fe/H] < −2.0 account for about 6% of the total luminosity of stars in the same metallicity range, a lower fraction than those previously found in the Fornax and WLM galaxies, but substantially higher than in the Milky Way halo. Conclusions. At low metallicities, the abundance patterns suggest that GCs in the Milky Way, dwarf galaxies, and M33 experienced similar enrichment histories and/or processes. At higher metallicities, the lower levels of α-enhancement in the GCs found in dwarf galaxies resemble the abundance patterns observed in field stars in nearby dwarfs. Constraining the presence of multiple populations in the GCs is complicated by the lack of information about detailed abundances in field stars of the corresponding metallicities. We suggest that correlations such as [Na/Fe] vs. [Ni/Fe] may prove useful for this purpose if an accuracy of ∼ 0.1 dex or better can be reached for the integrated-light measurements.

show abstract

“…Johnson et al (2017), studying the YSC population of M31, find that the CMF in this galaxy has a Schechter-type form,…”

Section: Cluster and Compact Association Evolutionmentioning

confidence: 97%

Legacy ExtraGalactic UV Survey with The Hubble Space Telescope: Stellar Cluster Catalogs and First Insights Into Cluster Formation and Evolution in NGC 628^∗

Adamo

Ryon

Messa

et al. 2017

ApJ

141

341

View full text Add to dashboard Cite

We report the large effort that is producing comprehensive high-level young star cluster (YSC) catalogs for a significant fraction of galaxies observed with the Legacy ExtraGalactic UV Survey (LEGUS) Hubble treasury program. We present the methodology developed to extract cluster positions, verify their genuine nature, produce multiband photometry (from NUV to NIR), and derive their physical properties via spectral energy distribution fitting analyses. We use the nearby spiral galaxy NGC 628 as a test case for demonstrating the impact that LEGUS will have on our understanding of the formation and evolution of YSCs and compact stellar associations within their host galaxy. Our analysis of the cluster luminosity function from the UV to the NIR finds a steepening at the bright end and at all wavelengths suggesting a dearth of luminous clusters. The cluster mass function of NGC 628The 1 is consistent with a power-law distribution of slopes~-2 and a truncation of a few times 10 5  M . After their formation, YSCs and compact associations follow different evolutionary paths. YSCs survive for a longer time frame, confirming their being potentially bound systems. Associations disappear on timescales comparable to hierarchically organized star-forming regions, suggesting that they are expanding systems. We find massindependent cluster disruption in the inner region of NGC 628, while in the outer part of the galaxy there is little or no disruption. We observe faster disruption rates for low mass (10 4  M ) clusters, suggesting that a massdependent component is necessary to fully describe the YSC disruption process in NGC 628.Astrophysical Journal, 841:131 (26pp), 2017 June 1 https:

show abstract

Panchromatic Hubble Andromeda Treasury. XVIII. The High-mass Truncation of the Star Cluster Mass Function

Cited by 104 publications

References 94 publications

The difference in metallicity distribution functions of halo stars and globular clusters as a function of galaxy type

The difference in metallicity distribution functions of halo stars and globular clusters as a function of galaxy type

Detailed abundance analysis of globular clusters in the Local Group

Legacy ExtraGalactic UV Survey with The Hubble Space Telescope: Stellar Cluster Catalogs and First Insights Into Cluster Formation and Evolution in NGC 628^∗

Contact Info

Product

Resources

About

Panchromatic Hubble Andromeda Treasury. XVIII. The High-mass Truncation of the Star Cluster Mass Function

Cited by 104 publications

References 94 publications

The difference in metallicity distribution functions of halo stars and globular clusters as a function of galaxy type

The difference in metallicity distribution functions of halo stars and globular clusters as a function of galaxy type

Detailed abundance analysis of globular clusters in the Local Group

Legacy ExtraGalactic UV Survey with The Hubble Space Telescope: Stellar Cluster Catalogs and First Insights Into Cluster Formation and Evolution in NGC 628∗

Contact Info

Product

Resources

About

Legacy ExtraGalactic UV Survey with The Hubble Space Telescope: Stellar Cluster Catalogs and First Insights Into Cluster Formation and Evolution in NGC 628^∗