Astronomy and Astrophysics – Astrophysics
Scientific paper
2004-06-10
Astronomy and Astrophysics
Astrophysics
13 pages, 3 figures, to appear in the ApJ Supplement, September 2004 (Spitzer Special Issue)
Scientific paper
10.1086/423205
Imaging of the Antennae galaxies (NGC 4038/4039) with the Infrared Array Camera (IRAC) aboard the Spitzer Space Telescope reveals large concentrations of star forming activity away from both nuclei of the two merging galaxies. These images confirm earlier findings based on ISO data with lower angular resolution. The short wavelength emission shows numerous compact sources identified as stellar clusters. At the longer wavelengths, bright, more amorphous and filamentary features correlate well with the known distributions of denser gas, warm dust, and HII regions. There are also fainter, more diffuse components at all wavelengths that permeate the entire region and extend into the two tidal tails. Non-stellar dust emission dominates the 5.8 and 8.0 micron images, accounting for as much as 79% of the light at 5.8 micron and 95% at 8 micron, averaged over the entire galaxy. Assuming that the non-stellar emission traces star formation, the IRAC data provide a view into the total underlying star forming activities unaffected by obscuration. Using the flux ratio of non-stellar to stellar emission as a guide, we map the local star formation rate in the Antennae and compare that to similar measurements in both normal and infrared-luminous galaxies. This rate in the active regions is found to be as high as those seen in starburst and some ultra-luminous infrared galaxies on ``per unit mass'' basis. The two galactic centers actually have lower star forming rates than the off-nuclear regions despite the presence of abundant dense gas and dust, suggesting that the latter is a necessary but not sufficient condition for on-going star formation.
Ashby Matt L. N.
Fazio Giacomo
Forrest William John
Huang Sheng-Jun
Pahre Michael A.
No associations
LandOfFree
The Off-nuclear Starbursts In NGC 4038/4039 (The Antennae Galaxies) does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with The Off-nuclear Starbursts In NGC 4038/4039 (The Antennae Galaxies), we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Off-nuclear Starbursts In NGC 4038/4039 (The Antennae Galaxies) will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-105844