Results 41 to 50 of about 241,163 (335)
The white dwarf luminosity function. I. Statistical errors and alternatives [PDF]
, 2006 Over the years, several methods have been proposed to compute galaxy luminosity functions, from the most simple ones -counting sample objects inside a given volume- to very sophisticated ones -like the C- method, the STY method or the Choloniewski method,
Abazajian +59 more
core +3 more sources
New model for calculation the radius of comet’s nucleus [PDF]
E3S Web of ConferencesIn this work, a new equation derived to obtain some physical properties like radius and luminosity of comets using distances between the comet, the Earth and the Sun that represent the geocentric distance and heliocentric distance at applying it to a ...
Mohammed Abd-AL Hamza Mariam +1 more
doaj +1 more source
The Luminosity Function of ω Centauri [PDF]
The Astronomical Journal, 1999 Deep HST-WFPC2 observations of the stellar population in the globular cluster Omega Cen (NGC 5139) have been used to measure the luminosity function of main sequence stars at the low-mass end. Two fields have been investigated, located respectively ~4.6' and ~7' away from the cluster center, or near the half-light radius of this cluster (~4.8').
openaire +3 more sources
ВЛИЯНИЕ ГРАВИТАЦИОННОГО ЛИНЗИРОВАНИЯ НА ФУНКЦИЮ СВЕТИМОСТИ КВАЗАРОВ
Odessa Astronomical Publications, 2011 The function of quasar distribution on apparent brightness is discussed. This function is found on base of suggestion that quasars, at least partly, are strong gravitational lensing images of the active nuclei of distant galaxies.
Ю. Л. Бухмастова
doaj +1 more source
The Structure Function of Mid-infrared Variability in Low-redshift Active Galactic Nuclei
The Astrophysical Journal, 2023 Using the multi-epoch mid-infrared (MIR) photometry from the Wide-field Infrared Survey Explorer spanning a baseline of ∼10 yr, we extensively investigate the MIR variability of nearby active galactic nuclei (AGNs) at 0.15 < z < 0.4.
Suyeon Son, Minjin Kim, Luis C. Ho
doaj +1 more source
The overdensities of galaxy environments as a function of luminosity and color [PDF]
, 2002 We study the mean environments of galaxies in the Sloan Digital Sky Survey as a function of rest-frame luminosity and color. Overdensities in galaxy number are estimated in $8 h^{-1} \mathrm{Mpc}$ and $1 h^{-1} \mathrm{Mpc}$ spheres centered on $125,000$
Daniel J. Eisenstein +16 more
core +2 more sources
General Physical Properties of Fermi Blazars
The Astrophysical Journal Supplement Series, 2023 We study the general physical properties of Fermi blazars using the Fermi fourth source catalog data (4FGL-DR2). The quasi-simultaneous multiwavelength data of Fermi blazars are fitted by using the one-zone leptonic model to obtain some physical ...
Yongyun Chen +8 more
doaj +1 more source
Energies, 2023 To restrain the environmental impact of modern SI engines, igniters must guarantee stable combustions with low cycle-to-cycle variability in extreme operating conditions (high EGR, ultra-lean), via high energy release in the combustion chamber.
Roberto Martinelli +5 more
doaj +1 more source
Estimating galaxy luminosity functions. [PDF]
The Astronomical Journal, 1997 29 pages, uses AASTeX 4.0 macros. Includes 6 tables and 8 Postscript figures.
openaire +4 more sources
Luminosity functions of cluster galaxies [PDF]
Astronomy & Astrophysics, 2018 We derive NUV luminosity functions for 6471 NUV detected galaxies in 28 0.02 < z < 0.08 clusters and consider their dependence on cluster properties. We consider optically red and blue galaxies and explore how their NUV LFs vary in several cluster subsamples, selected to best show the influence of environment.
Roberto De Propris +2 more
openaire +6 more sources