A spectroscopic method for determining the luminosities of spiral galaxies and estimating their stellar population

Other

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

22

Astronomical Spectroscopy, Galactic Nuclei, Luminosity, Spiral Galaxies, Star Distribution, Virgo Galactic Cluster, Abundance, Galactic Evolution, Galactic Structure, Globular Clusters, Optical Scanners

Scientific paper

Spectra of the nuclei of 44 normal spiral galaxies have been obtained using the McGraw-Hill Observatory intensified Reticon scanner. A composite spectral index, Σ, has been formed which measures the strengths of Ca II, Hδ , CH, and Mg, all of which correlate with absolute magnitude of the nuclear bulge. It is found that this index can predict the magnitudes of normal galaxies with a dispersion of 0.5 mag. This index is used to show that many galaxies within 6° of the Virgo cluster center, normally assumed to be members, may not be at the mean cluster distance.
Using the same instrument, we also obtained fluxed spectra of halo globular clusters and solar neighborhood stars of both Population I and II. These data were used to construct simple population models for the nuclei of late-type spiral galaxies. It was found that, except in the case of the ∼2" semistellar nucleus in M33, the line strengths of Sc galaxy nuclei fit well models constructed from globular cluster observations but could not be reproduced using only a Population I stellar mix. The reverse was true, on the other hand, for the semistellar nucleus of M33, where a good fit is obtained by using young star light plus a smaller contribution from an old metalpoor population.
We interpret this to indicate that the predominant light from the amorphous nuclear bulges of late-type spiral nuclei is old, but some of these galaxies may have had recent bursts of star formation that affect the spectral characteristics of a central component of the nucleus.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

A spectroscopic method for determining the luminosities of spiral galaxies and estimating their stellar population 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 A spectroscopic method for determining the luminosities of spiral galaxies and estimating their stellar population, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A spectroscopic method for determining the luminosities of spiral galaxies and estimating their stellar population will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-927806

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.