A Caltech Library Service

The dependence of the hierarchical distribution of star clusters on galactic environment

Menon, Shyam H. and Grasha, Kathryn and Elmegreen, Bruce G. and Federrath, Christoph and Krumholz, Mark R. and Calzetti, Daniela and Sánchez, Néstor and Linden, Sean T. and Adamo, Angela and Messa, Matteo and Cook, David O. and Dale, Daniel A. and Grebel, Eva K. and Fumagalli, Michele and Sabbi, Elena and Johnson, Kelsey E. and Smith, Linda J. and Kennicutt, Robert C. (2021) The dependence of the hierarchical distribution of star clusters on galactic environment. Monthly Notices of the Royal Astronomical Society, 507 (4). pp. 5542-5566. ISSN 0035-8711. doi:10.1093/mnras/stab2413.

[img] PDF - Published Version
See Usage Policy.

[img] PDF - Accepted Version
See Usage Policy.


Use this Persistent URL to link to this item:


We use the angular two-point correlation function (TPCF) to investigate the hierarchical distribution of young star clusters in 12 local (3–18 Mpc) star-forming galaxies using star cluster catalogs obtained with the Hubble Space Telescope (HST) as part of the Treasury Program Legacy ExtraGalactic UV Survey. The sample spans a range of different morphological types, allowing us to infer how the physical properties of the galaxy affect the spatial distribution of the clusters. We also prepare a range of physically motivated toy models to compare with and interpret the observed features in the TPCFs. We find that, conforming to earlier studies, young clusters (⁠T ≲ 10 Myr⁠) have power-law TPCFs that are characteristic of fractal distributions with a fractal dimension D₂, and this scale-free nature extends out to a maximum scale l_(corr) beyond which the distribution becomes Poissonian. However, l_(corr), and D₂ vary significantly across the sample, and are correlated with a number of host galaxy physical properties, suggesting that there are physical differences in the underlying star cluster distributions. We also find that hierarchical structuring weakens with age, evidenced by flatter TPCFs for older clusters (⁠T ≳ 10 Myr⁠), that eventually converges to the residual correlation expected from a completely random large-scale radial distribution of clusters in the galaxy in ∼100 Myr⁠. Our study demonstrates that the hierarchical distribution of star clusters evolves with age, and is strongly dependent on the properties of the host galaxy environment.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper ItemCode
Menon, Shyam H.0000-0001-5944-291X
Grasha, Kathryn0000-0002-3247-5321
Elmegreen, Bruce G.0000-0002-1723-6330
Federrath, Christoph0000-0002-0706-2306
Krumholz, Mark R.0000-0003-3893-854X
Calzetti, Daniela0000-0002-5189-8004
Sánchez, Néstor0000-0002-0042-3180
Linden, Sean T.0000-0002-1000-6081
Adamo, Angela0000-0002-8192-8091
Messa, Matteo0000-0003-1427-2456
Cook, David O.0000-0002-6877-7655
Dale, Daniel A.0000-0002-5782-9093
Grebel, Eva K.0000-0002-1891-3794
Fumagalli, Michele0000-0001-6676-3842
Sabbi, Elena0000-0003-2954-7643
Johnson, Kelsey E.0000-0001-8348-2671
Smith, Linda J.0000-0002-0806-168X
Kennicutt, Robert C.0000-0001-5448-1821
Additional Information:© 2021 The Author(s). Published by Oxford University Press on behalf of Royal Astronomical Society. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model ( Accepted 2021 August 6. Received 2021 August 5; in original form 2021 June 22. Published: 23 August 2021. We thank the anonymous referee for a constructive review that improved the quality of the paper. SHM would like to thank Dimitrios Gouliermis, James Beattie, and Piyush Sharda for insightful discussions during the course of the project. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with program # 13364. CF acknowledges funding provided by the Australian Research Council through Future Fellowship FT180100495, and the Australia-Germany Joint Research Cooperation Scheme (UA-DAAD). MRK acknowledges funding from the Australian Research Council through its Discovery Projects and Future Fellowship funding schemes, awards DP190101258 and FT180100375. MM acknowledges the support of the Swedish Research Council, Vetenskapsrådet (internationell postdok 2019-00502). This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement no. 757535). The following software tools were used for analysis and plotting: NUMPY (Harris et al. 2020), SCIPY (Virtanen et al. 2020), MATPLOTLIB (Hunter 2007), and CORNER (Foreman-Mackey 2016). Some of the figures used in this work make use of the CMASHER package (van der Velden 2020). This research made use of ASTROPY,8 a community-developed core PYTHON package for Astronomy (Astropy Collaboration 2013, 2018). This research has also made use of NASA’s Astrophysics Data System (ADS) Bibliographic Services. Data Availability: The data (cluster catalogs) underlying this article are publicly available online on the MAST9 for all galaxies except NGC 3627 and NGC 5457, which will be published in a forthcoming paper (Linden et al., in preparation). The tools and code to reproduce the analysis and plots of the paper are publicly available at
Group:Infrared Processing and Analysis Center (IPAC)
Funding AgencyGrant Number
NASANAS 5-26555
Australian Research CouncilFT180100495
Australia-Germany Joint Research Cooperation Scheme (UA-DAAD)UNSPECIFIED
Australian Research CouncilDP190101258
Australian Research CouncilFT180100375
Swedish Research Council2019-00502
European Research Council (ERC)757535
Subject Keywords:ISM: structure – galaxies: star clusters: general – galaxies: star formation – galaxies: statistics – galaxies: stellar content – galaxies: structure
Issue or Number:4
Record Number:CaltechAUTHORS:20211104-154229618
Persistent URL:
Official Citation:Shyam H Menon, Kathryn Grasha, Bruce G Elmegreen, Christoph Federrath, Mark R Krumholz, Daniela Calzetti, Néstor Sánchez, Sean T Linden, Angela Adamo, Matteo Messa, David O Cook, Daniel A Dale, Eva K Grebel, Michele Fumagalli, Elena Sabbi, Kelsey E Johnson, Linda J Smith, Robert C Kennicutt, The dependence of the hierarchical distribution of star clusters on galactic environment, Monthly Notices of the Royal Astronomical Society, Volume 507, Issue 4, November 2021, Pages 5542–5566,
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:111752
Deposited By: Tony Diaz
Deposited On:04 Nov 2021 16:10
Last Modified:04 Nov 2021 16:10

Repository Staff Only: item control page