The luminous starburst galaxy UGC 8387

Details The luminous starburst galaxy UGC 8387 The luminous starburst galaxy UGC 8387

Feb 1995

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1995apj...439..623s&link_type=abstract

The Astrophysical Journal, Part 1 (ISSN 0004-637X), vol. 439, no. 2, p. 623-636

Astronomy and Astrophysics

Astrophysics

20

Astronomical Spectroscopy, Data Reduction, Image Analysis, Luminosity, Star Formation, Starburst Galaxies, H Ii Regions, Infrared Spectra, Interstellar Extinction, Microwave Spectra, Radio Spectra, Spectrum Analysis

Scientific paper

We present broad-band J, H, and K images and K-band spectroscopy of the luminous starburst galaxy UGC 8387. The images show a disturbed morphology, tidal tails, and a single elongated nucleus. Near infrared color maps constructed from the images reveal that the nucleus region is highly reddened. Strong emission from the central 3 arcseconds in the 2.166 micrometer Brackett gamma, 2.122 micrometer H2 v = 1-0 S(1), and 2.058 micrometer He I lines is present in the K-band spectrum. From the Brackett gamma and published radio fluxes, we find an optical depth toward the nucleus of tauV approximately 24. The CO band heads produce strong absorption in the spectral region long-ward of 2.3 micrometers. We measure a 'raw' CO index of 0.17 +/- 0.02 mag, consistent with a population of K2 supergiants of K4 giants. The nuclear colors, however, are not consistent with an obscured population of evolved stars. Instead, the red colors are best explained by an obscured mixture of stellar and warm dust emission. The amount of dust emission predicted by the near-infrared colors exceeds that expected from comparisons to galactic H II regions. After correcting the spectrum of UGC 8387 for dust emission and extinction, we obtain a CO index of greater than or equal to 0.25 mag. This value suggests the stellar component of the 2.2 micrometer light is dominated by young supergiants. The infrared excess, LIR/LLy alpha derived for UGC 8387 is lower than that observed in galactic H II regions and M82. This implies that either the lower or upper mass cutoff of the initial mass function must be higher than those of local star-forming regions and M82. The intense nuclear starburst in this galaxy is presumably the result of merger activity; and we estimate the starburst age to be at least a few times 107 yr.

Affiliated with

Also associated with

No associations

Rating

The luminous starburst galaxy UGC 8387 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 luminous starburst galaxy UGC 8387, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The luminous starburst galaxy UGC 8387 will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1630585