Gary Mamon's Research Highlights

• Cosmology
  • 1^st measures of Ω_m=0.3 from groups of galaxies using internal galaxy motions (corrected for collapsing state of groups in sample, Mamon 1993) and baryonic fraction (from X-rays, Henriksen & Mamon 1994)
  • Initiator of 6dFGS spectroscopic survey (Jones et al. 2004 and 2009)
  • 1^st very detailed analysis of the NFW model (Łokas & Mamon 2001)
  • 1^st measure of 6D distribution function of ΛCDM halos in separable terms of energy and angular momentum (Wojtak, Łokas, Mamon et al. 2008)
  • 1^st measure of the intrinsic (1-halo term) galaxy number density profile of groups and clusters of galaxies: ≈ NFW out to 13 virial radii (Trevisan, Mamon & Stalder 2017)

• Mass - Orbit Modeling of Internal Motions
  • 1^st algorithms for velocity anisotropy inversion of spherical systems of known mass profile (Binney & Mamon 1982) and mass inversion for spherical systems of known velocity anisotropy profile (Mamon & Boué 2010)
  • 1^st expression as single integrals of mass and tracer density profiles of the radial profiles of line-of-sight velocity dispersion (Mamon & Łokas 2005b) and aperture velocity dispersion (isotropic systems: Mamon & Łokas 2005a)
  • 1^st breaking of mass / velocity anisotropy degeneracy in a cluster of galaxies (Łokas & Mamon 2003)
  • Rapid and versatile Bayesian algorithm (MAMPOSSt) to break mass / velocity anisotropy degeneracy in near-spherical systems (Mamon, Biviano & Boué 2013): 2nd lowest RMS errors among 23 algorithms on cluster masses (M₂₀₀) in challenge on mock clusters, where best algorithm was another of mine (Old, Wojtak, Mamon et al. 2015)
  • Red galaxies have more concentrated halos than blue galaxies of same stellar or halo mass: 1st direct evidence of galaxy assembly bias (Wojtak & Mamon 2013)
  • Cluster galaxy orbits are isotropic in the inner regions, regardless of morphological type, and increasingly radial in the outer regions from ellipticals to S0s to spirals (Mamon et al. 2019)
  • 1st joint measure of mass and extent of a concentration of compact objects (white dwarfs, neutron stars and stellar-mass black holes) in the inner parts of a core-collapsed globular cluster (Vitral & Mamon 2021)

• Compact Groups of Galaxies
  • Hickson Compact Groups are heavily contaminated by chance alignments of galaxies along line-of-sight (Mamon 1986), but 2/3 of mock Compact Groups selected with Hickson criteria are physically dense (Díaz-Giménez & Mamon 2010) or less than half (Díaz-Giménez et al. 2020)
  • 1^st group sample that shows strong signs of luminosity segregation and wide gap at bright-end of luminosity function (Díaz-Giménez, Mamon et al. 2012)
  • Discovery of nearest HCG-like compact group: in the Virgo cluster (Mamon 1989) and 1^st direct measurement of nature of a compact group ([same group] is a chance projection, Mamon 2008)

• Galaxy Formation
  • 1^st realization of cooling catastrophe: feedback mechanisms are required to prevent too much star formation in galaxies (Blanchard, Valls-Gabaud & Mamon 1992)
  • 1^st determination of main mechansim for mass acquisition of galaxies from cosmological simulations with sufficient mass resolution (gEs: dry major mergers, dEs and spirals: gas accretion, Cattaneo, Mamon et al. 2011)
  • 1^st prediction with semi-analytical models of the frequency of very young galaxies at z=0 (Mamon, Tweed, Thuan & Cattaneo 2011; Tweed et al. 2018) and measurement from 400 thousand spectra (Mamon et al. 2020)

• Environmental Effects on Galaxies
  • 1^st analytical calculation of rate of direct mergers of galaxies in clusters (Mamon 1992)
  • Semi-analytical model of galaxy formation with ram pressure stripping: little effect on frequency of S0 galaxies (Lanzoni, Guiderdoni, Mamon et al. 2005)
  • 1^st calculation of how far galaxies bounce out of clusters: 1-2.5 r_vir (Mamon et al. 2004)
  • 1st quantitative measure of (slow) quenching of star formation of galaxies in clusters (Mahajan, Mamon & Raychaudhury 2011)
  • Optimal MAGGIE group finder for environmental studies (Duarte & Mamon 2015)

• Elliptical Galaxies
  • Giant elliptical galaxies cannot have NFW-like total mass profiles: the stellar component dominates dark matter in the inner regions (Mamon & Łokas 2005a)
  • Stars in envelopes of giant ellipticals travel along very elongated orbits (Dekel et al. 2005)
  • Discovery of a new class of compact elliptical galaxy between UCDs and cEs (Chilingarian & Mamon 2008)

• Circumstellar Chemistry
  • 1^st complex photochemistry / radiative transfer calculations for circumstellar envelopes (Mamon, Glassgold & Omont 1987)
  • 1^st calculation of enhanced self-shielding of CO in circumstellar envelopes of carbon-rich stars (Mamon, Glassgold & Huggins 1988)
  • 1^st prediction of in-situ formation of H₂O in circumstellar envelopes of Young Stellar Objects (Glassgold, Mamon & Huggins 1991)