The structure and environment of young stellar clusters in spiral galaxies

By S. Larsen. 2003

160 citations recorded by the source corpus.

A search for stellar clusters has been carried out in 18 nearby spiral galaxies, using archive images from the Wide Field Planetary Camera 2 on board the Hubble Space Telescope. All of the galaxies have previously been imaged from the ground in UBVI. A catalogue of structural parameters, photometry and comments based on visual inspection of the clusters is compiled and used to investigate correlations between cluster structure, environment, age and mass. Least-squares fits to the data suggest correlations between both the full-width at half-maximum (FWHM) and half-light radius (Reff )o f the clusters and their masses (M) at about the 3σ level. Although both relations show a large scatter, the fits have substantially shallower slopes than for a constant-density relation (size ∝ M 1/3 ). However, many of the youngest clusters have extended halos which make the Reff determinations uncertain. There is no evidence for galaxy-to-galaxy variations in the mean cluster sizes. In particular, the mean sizes do not appear to depend on the host galaxy star formation rate surface density. Many of the youngest objects (age < 10 7 years) are located in strongly crowded regions, and about 1/3-1/2 of them are double or multiple sources. The HST images are also used to check the nature of cluster candidates identified in a previous ground-based survey. The contamination rate in the ground-based sample is generally less than about 20%, but some cluster identifications remain ambiguous because of crowding even with HST imaging, especially for the youngest objects.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/8fb6b726c14805d15b209cd14a6512cc66271300

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Citations in the corpus

The dynamical state of stellar structure in star‐forming regions (2011, background): “Indeed, first observational indications for such a relation have been found by Larsen & Richtler (2000), Larsen (2004), and recently also by Goddard et al. (2010), who obtain CFE∝ Σ0.”
Globular clusters as the relics of regular star formation in ‘normal’ high-redshift galaxies (2015, background): “The characteristic radius of nearby YMCs ofrh = 3.75 pc (Larsen 2004) thus becomesrh = 1.5 pc in cluster-forming galaxies atz ∼ 3.”
Inverse dynamical population synthesis: Constraining the initial conditions of young stellar clusters by studying their binary populations (2012, result): “10±0.03, found by Larsen (2004).”
Young Massive Star Clusters (2010, methodology): “Several studies have discussed the lack of any clear correlation between the size of a cluster and its mass or luminosity (Zepf et al. 1999, Larsen 2004, Scheepmaker et al. 2007).”
Evidence for the Strong Effect of Gas Removal on the Internal Dynamics of Young Stellar Clusters (2006, background): “This profile has been shown to fit young clusters in the Large Magellanic Cloud (LMC) better (EFF) as well as young massive clusters in galaxies outside the Local Group (e.g. Larsen 2004; Schweizer 2004).”
RADIATION PRESSURE FROM MASSIVE STAR CLUSTERS AS A LAUNCHING MECHANISM FOR SUPER-GALACTIC WINDS (2010, background): “Younger clusters of the same mass tend to have even smaller half-light radii, e.g. Larsen (2004) and McCrady & Graham (2007).”
Progenitors of Core-Collapse Supernovae (2009, background): “Thus single stars can be confused with the most compact stellar clusters which can have diameters of between 0.5-10 pc (Larsen 2004, Scheepmaker et al. 2007).”
On the fraction of star formation occurring in bound stellar clusters (2012, background): “…(Elmegreen & Falgarone 1996), but the understanding of the corresponding upper (e.g. Gieles et al. 2006a; Bastian 2008; Larsen 2009) and lower (e.g. Lada & Lada 2003; Moeckel et al. 2012) cluster mass limits requires more work, as does the distribution of initial cluster radii (e.g. Larsen 2004).”
Star cluster disruption by giant molecular clouds (2006, methodology): “We choose the use the recently observed relation between radius and mass of Larsen (2004), who fits a function of the form reff = AMc λ to a sample of young star clusters in nearby spiral galaxies and finds that A = 1.12 ± 0.35 and λ = 0.10± 0.03.”
Resolved Massive Star Clusters in the Milky Way and Its Satellites: Brightness Profiles and a Catalog of Fundamental Parameters (2005, background): “The physical parameters extracted for young massive clusters from fits of equation (2) by Elson, Fall, & Freeman (1987), MG03, and others (e.g., Larsen 2004) are generally confined to the central intensityI0, the scale radiusr0 (and perhaps an associated core radiusRc and/or effective radius Rh),…”
On the massive stellar population of the super star cluster Westerlund 1 (2005, background): “Indeed, by analogy with other young massive clusters we might expect the density profile of Wd 1 to be described by a EFF (Elson et al. 1987) King-like profile (Schweizer 2005; Larsen 2004); this will be addressed in a future paper in which we analyse VLT (NAOS CONICA & FORS1) imaging data.”