Astronomy and Astrophysics – Astronomy
Scientific paper
Jan 2012
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2012aas...21924628n&link_type=abstract
American Astronomical Society, AAS Meeting #219, #246.28
Astronomy and Astrophysics
Astronomy
Scientific paper
Isolated galaxies provide a means of assessing theories of formation and evolution. Past studies have employed a variety of techniques to obtain samples of isolated elliptical galaxies (IEGs), but the results of these studies have not provided a uniform understanding of IEG properties. Our goal is to examine the set of isolation criteria that yields a uniform sample of the most isolated early-type galaxies with minimal contamination from spiral galaxies. We use the Sloan Digital Sky Survey (SDSS) to identify IEGs in the nearby universe. Redshifts derived from the SDSS spectra permit a robust three-dimensional assessment of the environment surrounding the IEG candidates.
The study examined four criteria for selecting isolated early-type systems: 1. 2D radial separation between IEGs and neighboring galaxies, 2. 3D redshift difference, 3. The neighbor galaxy brightness limit, and 4. the Petrosian ratio (P50/P90), used to extract early-type systems. The examination of the selection criteria allowed us the ability to judge the relative importance of the individual criteria when building samples of IEGs.
The results indicate that multiple selection criteria can be used to create samples of IEGs. Specifically, each search resulted in samples with a population of low- to intermediate-luminosity, bluer than average early-type galaxies. However, some searches yielded samples with colors and luminosities associated with "typical” early-type systems. The selection criteria that identify the largest number of bright, red, isolated early-type systems are 2.0 Mpc radial separation, a redshift difference between IEG and any neighbor galaxy of Δcz 300 km s-1, a neighbor galaxy brightness limit of -18.0 ≤ MV ≤ -17.0, and a Petrosian ratio of 0.42 ≤ P50/P90 ≤ 0.36.
Fanelli Michael N.
Fuse Chris
Marcum Pam
Negron-Rivera Alfredo J.
No associations
LandOfFree
Investigating the Isolated Early-type Galaxy Selection Criteria 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 Investigating the Isolated Early-type Galaxy Selection Criteria, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Investigating the Isolated Early-type Galaxy Selection Criteria will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1579534