Tests of the Tully-Fisher relation. 1: Scatter in infrared magnitude versus 21 CM width

Statistics – Applications

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

64

Astronomical Photometry, Galactic Clusters, Infrared Imagery, Near Infrared Radiation, Spiral Galaxies, Astronomical Observatories, Red Shift, Velocity Distribution

Scientific paper

We examine the precision of the Tully-Fisher relation (TFR) using a sample of galaxies in the Coma region of the sky, and find that it is good to 5% or better in measuring relative distances. Total magnitudes and disk axis ratios are derived from H and I band surface photometry, and Arecibo 21 cm profiles define the rotation speeds of the galaxies. Using 25 galaxies for which the disk inclination and 21 cm width are well defined, we find an rms deviation of 0.10 mag from a linear TFR with dI/d(log Wc) = -5.6. Each galaxy is assumed to be at a distance proportional to its redshift, and an extinction correction of 1.4(1-b/a) mag is applied to the total I magnitude. The measured scatter is less than 0.15 mag using milder extinction laws from the literature. The I band TFR scatter is consistent with measurement error, and the 95% CL limits on the intrinsic scatter are 0-0.10 mag. The rms scatter using H band magnitudes is 0.20 mag (N = 17). The low width galaxies have scatter in H significantly in excess of known measurement error, but the higher width half of the galaxies have scatter consistent with measurement error. The H band TFR slope may be as steep as the I band slope. As the first applications of this tight correlation, we note the following: (1) the data for the particular spirals commonly used to define the TFR distance to the Coma cluster are inconsistent with being at a common distance and are in fact in free Hubble expansion, with an upper limit of 300 km/s on the rms peculiar line-of-sight velocity of these gas-rich spirals; and (2) the gravitational potential in the disks of these galaxies has typical ellipticity less than 5%. The published data for three nearby spiral galaxies with Cepheid distance determinations are inconsistent with our Coma TFR, suggesting that these local calibrators are either ill-measured or peculiar relative to the Coma Supercluster spirals, or that the TFR has a varying form in different locales.

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

Tests of the Tully-Fisher relation. 1: Scatter in infrared magnitude versus 21 CM width 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 Tests of the Tully-Fisher relation. 1: Scatter in infrared magnitude versus 21 CM width, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Tests of the Tully-Fisher relation. 1: Scatter in infrared magnitude versus 21 CM width will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1862480

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