Results 41 to 50 of about 153,264 (305)
Host Galaxies and the Spectral Variability of Quasars [PDF]
, 2001 Brightness variability of QSOs is associated with variations of the spectral energy distribution in the optical-UV range. The observed change of the spectral shape depends on the contribution of the host galaxy. Simulations, taking into account luminosities and spectra expected for the host galaxies, are compared with the observed spectral variability ...
VAGNETTI, FAUSTO, Trevese, D.
openaire +3 more sources
Spectral Characteristics of Common Reed Beds: Studies on Spatial and Temporal Variability
Remote Sensing, 2016 Reed beds are the second largest producer of biomass in Olkiluoto Island. Quantitative information on the extent and amount of reed stands is an integral part of the biosphere assessment related to long-term safety analysis of nuclear fuel repository ...
Jyrki Tuominen, Tarmo Lipping
doaj +1 more source
OPTICAL MICROVARIABILITY IN QUASARS: SPECTRAL VARIABILITY [PDF]
The Astrophysical Journal, 2010 We present a method that we developed to discern where the optical microvariability (OM) in quasars originates: in the accretion disk (related to thermal processes) or in the jet (related to non-thermal processes). Analyzing nearly simultaneous observations in three different optical bands of continuum emission, we are able to determine the origin of ...
Ramirez, A. +2 more
openaire +2 more sources
Variability of updated finite element models and their predictions consistent with vibration measurements [PDF]
, 2011 A case study on a small-scale laboratory vehicle frame is used to investigate the variability of the updated finite element (FE) models that arises from model and measurement errors and demonstrate the effect of this variability on response predictions ...
Natsiavas, S. +11 more
core +1 more source
Quadratic Clustering-Based Simplex Volume Maximization for Hyperspectral Endmember Extraction
Applied Sciences, 2022 The existence of intra-class spectral variability caused by differential scene components and illumination conditions limits the improvement of endmember extraction accuracy, as most endmember extraction algorithms directly find pixels in the ...
Xiangyue Zhang, Yueming Wang, Tianru Xue
doaj +1 more source
Spectral asymptotics for $V$-variable Sierpinski gaskets [PDF]
Annales de l'Institut Henri Poincaré, Probabilités et Statistiques, 2017 The family of $V$-variable fractals provides a means of interpolating between two families of random fractals previously considered in the literature; scale irregular fractals ($V=1$) and random recursive fractals ($V=\infty$). We consider a class of $V$-variable affine nested fractals based on the Sierpinski gasket with a general class of measures. We
Freiberg, U. +2 more
openaire +5 more sources
OPTICAL POLARIZATION AND SPECTRAL VARIABILITY IN THE M87 JET [PDF]
The Astrophysical Journal, 2011 14 pages, 7 figures, ApJ, in ...
Perlman, Eric S. +12 more
openaire +4 more sources
Sun-as-a-star variability of Hα and Ca II 854.2 nm lines
Frontiers in Astronomy and Space SciencesStudies of stellar magnetic fields mostly rely on proxies derived from chromospheric lines, typically forming in the UV and shorter wavelengths and therefore accessible only from space based observatories.
Garrett Zills +3 more
doaj +1 more source
The spectral variability of FSRQs
, 2011 The optical variability of 29 flat spectrum radio quasars in SDSS Stripe 82 region are investigated by using DR7 released multi-epoch data. All FSRQs show variations with overall amplitude ranging from 0.24 mag to 3.46 mag in different sources. About half of FSRQs show a bluer-when-brighter trend, which is commonly observed for blazars.
Gu, Minfeng, Ai, Y. L.
openaire +2 more sources
The tritone paradox: Effects of spectral variables [PDF]
Perception & Psychophysics, 1987 A paradoxical two-tone pattern is explored, which is heard as ascending when played in one key but as descending when played in a different key. The pattern thus provides a striking counterexample to the principle of invariance under transposition. In addition, the pattern in any one key is heard as ascending by some listeners but as descending by ...
openaire +2 more sources