The fundamental plane of brightest cluster galaxies and isolated elliptical galaxies

• Published in: Astrophysics and space science 2020-08, Vol.365 (8), Article 142
• Main Authors: Samir, R. M., Takey, A., Shaker, A. A.
• Format: Article
• Language: English
• Subjects: Astrobiology; Astronomy; Astrophysics; Astrophysics and Astroparticles; Cosmology; Elliptical galaxies; Galactic clusters; Luminosity; Object recognition; Observations and Techniques; Original Article; Physics; Physics and Astronomy; Sky surveys (astronomy); Slopes; Space Exploration and Astronautics; Space Sciences (including Extraterrestrial Physics; Space telescopes; Spectroscopy; Wavelengths
• ISSN: 0004-640X; 1572-946X
• DOI: 10.1007/s10509-020-03857-8

This work aims to investigate the fundamental plane, the Kormendy, the Faber-Jackson, and the size-luminosity relations for two galaxy samples (brightest cluster galaxies (BCGs) and isolated elliptical galaxies (IEs)) in different environments. These relations are investigated in different wavelength bands, griz , of the Sloan Digital Sky Survey (SDSS). We constructed a sample of 2002 BCGs from the redMaPPer clusters catalog with spectroscopic redshifts in the range ( 0.076 ⩽ z ⩽ 0.394 ). The sample of IEs consists of 550 objects and is extracted from the catalog of isolated galaxies (SDSS-based Isolated Galaxies, SIG) with spectroscopic redshifts range ( 0.01 ⩽ z ⩽ 0.08 ). In general, we found that slopes of all studied scaling relations are waveband dependent except for the Faber-Jackson relation. The fundamental plane (FP) for both samples steepens as one moves from shorter to longer wavelengths. We found that BCGs lie on a different FP from that of IEs. In average the coefficient a of BCGs is larger than that of IEs by about 5 σ , while the coefficient b is larger by about 11 σ . By studying the Kormendy relation (KR), we found that its slope varies through the waveband for both samples. Also, the slope of BCGs is smaller than that of IEs by about 7 σ , while the intercept is smaller by about 12 σ . We also examined the Faber-Jackson (FJ) relation and found that its slope is similar for all wavebands for both samples. BCGs defines a steeper FJ relation than IEs such that L ∝ σ 6.25 for BCGs and L ∝ σ 2.63 for IEs. We also studied the size-luminosity relation and found that its slope is decreasing slightly with waveband for both samples. We also found that BCGs define a steeper size-luminosity relation than IEs, in average the slope of BCGs is greater than that of IEs by ∼ 7 σ .