Photometric Properties of the Arp 220 Super Star Clusters

Abstract

We investigate the photometric properties of six super stellar clusters (SSCs) seen in both the optical and near-infrared Hubble Space Telescope images of the local ultraluminous starburst galaxy Arp 220. Three of the SSCs are located in the central 0.5 kpc region. The remaining three are in the circumnuclear region between 0.5 kpc and 2.5 kpc from the centre. Comparing the observed spectral energy distributions (SEDs) of the SSCs with the Starburst99 models of Leitherer et al., we confirm that all the three nuclear SSCs are heavily obscured ($A_V\sim 10$ mag). Considering the results from this comparison in conjunction with measurements of the near-infrared CO absorption index and of millimetre CO line widths and luminosities, we estimate the ages of the nuclear SSCs to be $10^7-10^8$ yrs. The bolometric luminosity of the three nuclear SSCs is at most one-fifth of the total bolometric luminosity of Arp 220. On the other hand, the circumnuclear SSCs have little internal extinction ($A_V\le$ 1 mag). These contribute negligibly to the total bolometric luminosity.

8 pages, 5 figures. Accepted for publication in MNRAS

References in corpus (4)

• Starburst99: Synthesis Models for Galaxies with Active Star Formation
• Rotating Nuclear Rings and Extreme Starbursts in Ultraluminous Galaxies
• What Powers Ultra-luminous IRAS Galaxies?
• High Spatial Resolution Imaging of Arp 220 from 3 - 25 microns

Cited by in corpus (15)

• Two Populations of Young Massive Star Clusters in Arp 220
• Spectral Energy Distributions of Dusty Galaxies
• The Chandra View of Galaxy Mergers
• Clumpy and Extended Starbursts in the Brightest Unlensed Submillimeter Galaxies
• Merging Galaxies in Goods-s: First Extragalactic Results from Keck Laser Adaptive Optics
• Search for Tidal Dwarf Galaxies Candidates in a Sample of Ultraluminous Infrared Galaxies
• Hot dust in normal star-forming galaxies: JHKL' photometry of the ISO Key Project sample
• Nucler star formation in NGC 6240
• Changing physical conditions in star-forming galaxies between redshifts 0 < z < 4: [OIII]/Hb evolution
• Potential formation sites of super star clusters in ultra-luminous infrared galaxies
• The Infrared Properties of Super Star Clusters: Predictions from Three-Dimensional Radiative Transfer Models
• X-ray observations of sub-mm LABOCA galaxies in the eCDFS
• A possible physical connection between helium-rich stellar populations of massive globular clusters and the UV upturn of galactic spheroids
• A Massive Dense Gas Cloud close to the Nucleus of the Seyfert galaxy NGC 1068
• Star Cluster Formation and Star Formation: The Role of Environment and Star Formation Efficiencies