Deep Near-Infrared Imaging and Photometry of the Antennae Galaxies with WIRC

We present deep near-infrared images of the Antennae galaxies, taken with the Palomar Wide-Field Infrared Camera (WIRC). The images cover a 4.′33 × 4.′33 (24.7 × 24.7 kpc) area around the galaxy interaction zone. We derive J- and Ks-band photometric fluxes for 172 infrared star clusters and discuss details of the two galactic nuclei and the overlap region. We also discuss the properties of a subset of 27 sources that have been detected with WIRC, HST, and the VLA. The sources in common are young clusters of less than 10 Myr, which show no correlation between their infrared colors and 6 cm radio properties. These clusters cover a wide range in infrared color due to extinction and evolution. The average extinction is about AV ~ 2 mag, while the reddest clusters may be reddened by up to 10 mag.

[1]  G. Fazio,et al.  The Off-Nuclear Starbursts in NGC 4038/4039 (The Antennae Galaxies) , 2004, astro-ph/0406276.

[2]  J. Hibbard,et al.  The Stellar Content of the Southern Tail of NGC 4038/4039 and a Revised Distance , 2003, astro-ph/0311200.

[3]  K. Sellgren,et al.  Stellar Populations in NGC 4038/39 (the Antennae): Exploring a Galaxy Merger Pixel by Pixel , 2003, astro-ph/0306325.

[4]  Stephen S. Eikenberry,et al.  A Wide-Field Infrared Camera for the Palomar 200-inch Telescope , 2003, SPIE Astronomical Telescopes + Instrumentation.

[5]  B. Whitmore,et al.  What Fraction of the Young Clusters in the Antennae Galaxies Are “Missing”? , 2002, astro-ph/0207100.

[6]  S. Murray,et al.  Chandra Observations of “The Antennae” Galaxies (NGC 4038/4039). II. Detection and Analysis of Galaxian X-Ray Sources , 2002, astro-ph/0203174.

[7]  N. Thatte,et al.  Dynamical masses of young star clusters in NGC 4038/4039 , 2001, astro-ph/0111560.

[8]  S. M. Fall,et al.  A Multiwavelength Study of the Young Star Clusters and Interstellar Medium in the Antennae Galaxies , 2001, astro-ph/0105174.

[9]  Susan G. Neff,et al.  VLA Observations of the Nearby Merger NGC 4038/4039: H II Regions and Supernova Remnants in the “Antennae” , 2000 .

[10]  Canada,et al.  High-Resolution Imaging of Molecular Gas and Dust in the Antennae (NGC 4038/39): Super Giant Molecular Complexes , 2000, astro-ph/0005208.

[11]  J. Graham,et al.  Infrared Spectroscopy of a Massive Obscured Star Cluster in the Antennae Galaxies (NGC 4038/9) with NIRSPEC , 1999, The Astrophysical journal.

[12]  S. M. Fall,et al.  The Luminosity Function of Young Star Clusters in “the Antennae” Galaxies (NGC 4038/4039) , 1999, astro-ph/9907430.

[13]  Denis Foo Kune,et al.  Starburst99: Synthesis Models for Galaxies with Active Star Formation , 1999, astro-ph/9902334.

[14]  B. Whitmore,et al.  Hubble space telescope observations of young star clusters in NGC-4038/4039, 'the antennae' galaxies , 1995 .

[15]  G. Rieke,et al.  The interstellar extinction law from 1 to 13 microns. , 1985 .

[16]  E. Salpeter.  The Luminosity function and stellar evolution , 1955 .