THE SNAPSHOT HUBBLE U-BAND CLUSTER SURVEY (SHUCS). II. THE STAR CLUSTER POPULATION OF NGC 2997

• We study the star cluster population of NGC 2997, a giant spiral galaxy located at 9.5 Mpc and targeted by the Snapshot Hubble U-band Cluster Survey (SHUCS). Combining our U-band imaging from SHUCS with archival BVI imaging from the Hubble Space Telescope, we select a high confidence sample of clusters in the circumnuclear ring and disk through a combination of automatic detection procedures and visual inspection. The cluster luminosity functions in all four filters can be approximated by power laws with indices of -1.7 to -2.3. Some deviations from pure power-law shape are observed, hinting at the presence of a high-mass truncation in the cluster mass function. However, upon inspection of the cluster mass function, we find it is consistent with a pure power law of index -2.2 +/- 0.2 despite a slight bend at similar to 2.5 x 10(4) M-circle dot. No statistically significant truncation is observed. From the cluster age distributions, we find a low rate of disruption(zeta similar to -0.1) in both the disk and circumnuclear ring. Finally, we estimate the cluster formation efficiency (Gamma) over the last 100 Myr in each region, finding 7% +/- 2% for the disk, 12% +/- 4% for the circumnuclear ring, and 10% +/- 3% for the entire UBVI footprint. This study highlights the need for wide-field UBVI coverage of galaxies to study cluster populations in detail, though a small sample of clusters can provide significant insight into the characteristics of the population.

Ämnesord

NATURVETENSKAP  -- Fysik -- Astronomi, astrofysik och kosmologi (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Astronomy, Astrophysics and Cosmology (hsv//eng)

Nyckelord

galaxies: individual (NGC 2997)

galaxies: star clusters: general

galaxies: star formation

surveys

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