Results 31 to 40 of about 241,163 (335)

The Planetary Nebula Luminosity Function [PDF]

open access: yesProceedings of the International Astronomical Union, 2006
AbstractAlthough the method has no theoretical explanation, the [Oiii]λ5007Å planetary nebula luminosity function (PNLF) is an extremely valuable tool for obtaining accurate (< 10%) extragalactic distances out to ~ 18 Mpc. Because the PNLF works in large galaxies of all Hubble types, it is one of the best tools we have for cross-checking the results
openaire   +5 more sources

On the Number of Galaxies at High Redshift

open access: yesGalaxies, 2015
The number of galaxies at a given flux as a function of the redshift, z, is derived when the z-distance relation is non-standard. In order to compare different models, the same formalism is also applied to the standard cosmology.
Lorenzo Zaninetti
doaj   +1 more source

Radio Luminosity Functions [PDF]

open access: yesSymposium - International Astronomical Union, 1996
Luminosity functions give the space densities of source populations as functions of spectral luminosity. They constrain source physics, clustering, cosmological evolution, and contributions to the radiation background. Extragalactic radio sources span eight decades of luminosity, so dividing them into luminosity ranges effectively separates them by ...
openaire   +2 more sources

The ISO 170um Luminosity Function of Galaxies [PDF]

open access: yes, 2005
We constructed a local luminosity function (LF) of galaxies using a flux-limited sample (S_170 > 0.195Jy) of 55 galaxies at z < 0.3 taken from the ISO FIRBACK survey at 170um.
Dennefeld, Michel   +5 more
core   +2 more sources

Tracing Galaxy Evolution by Their Present-Day Luminosity Function

open access: yesOpen Astronomy, 2011
Galaxy luminosity functions are derived for different morphological types and various colors of galaxies, to trace the evolutionary effects which a priori should be different for void and supercluster galaxies.
Tempel E.
doaj   +1 more source

Luminosity Functions of Planetary Nebulae [PDF]

open access: yesSymposium - International Astronomical Union, 1997
Planetary nebulae have recently been shown to be useful as standard candles (Ciardullo et al. 1989, ApJ, 339, 53; Jacoby 1989, ApJ, 339, 39). Distances to many galaxies have been determined by fitting a planetary nebula luminosity function (PNLF) to observations of the OIII 5007å line of PNe.
Marcelle Tremblay, Sun Kwok
openaire   +2 more sources

Theoretical Systematics in Testing the Cosmological Principle with the Kinematic Quasar Dipole

open access: yesThe Astrophysical Journal, 2023
The Cosmological Principle (CP) is part of the foundation that underpins the standard model of the Universe. In the era of precision cosmology, when stress tests of the standard model are uncovering various tensions and possible anomalies, it is critical
Caroline Guandalin   +3 more
doaj   +1 more source

On the origin of the galaxy luminosity function [PDF]

open access: yesMonthly Notices of the Royal Astronomical Society, 2004
Evidence is summarized that suggests that when a protogalaxy collapses, a fraction $f$ of its gas fails to heat to the virial temperature, where $f$ is large for haloes less massive than the value $M^*$ associated with $L^*$ galaxies. Stars and galaxies form only from the cool gas fraction.
openaire   +4 more sources

The dust un-biased cosmic star formation history from the 20 cm VLA-COSMOS survey [PDF]

open access: yes, 2008
We derive the cosmic star formation history (CSFH) out to z=1.3 using a sample of ~350 radio-selected star-forming galaxies, a far larger sample than in previous, similar studies.
Afonso   +43 more
core   +2 more sources

The Effect of Superpositions on the Planetary Nebula Luminosity Function

open access: yesThe Astrophysical Journal, 2023
Planetary nebula (PN) surveys in systems beyond ∼10 Mpc often find high-excitation, point-like sources with [O iii ] λ 5007 fluxes greater than the apparent bright-end cutoff of the planetary nebula luminosity function (PNLF).
Owen Chase   +3 more
doaj   +1 more source

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