The quasars’ redshift estimation method based on piecewise Gaussian fitting

Research on Piecewise Linear Fitting Method Based on Least Square Method in 3D Space Points

Because the known data cannot be completely found to determine the function of the corresponding relationship, it is needed to describe the data in tabular form. As the research goes on, people want to use some simple mathematical functions to express the relationship between the data and the data. In the process of data processing, the least square method is one of the most common methods. Bas...

Photometric redshift estimation using Gaussian processes

We present a comparison between Gaussian processes (GPs) and artificial neural networks (ANNs) as methods for determining photometric redshifts for galaxies, given training set data. In particular, we compare their degradation in performance as the training set size is degraded in ways which might be caused by the observational limitations of spectroscopy. Using publicly-available regression co...

High - redshift obscured quasars

Using mid-infrared and radio criteria, we select a sample of candidate z ∼ 2 obscured quasars. Optical spectroscopy confirms about half of these as type-2 quasars, and modelling the population suggests 50-80% of the quasars are obscured. We find some flat radio spectrum type-2 quasars, and tentative evidence for obscuration unrelated to the torus. Using a similar sample, we also find evidence f...

Intrinsic redshift in quasars

A Jump-Preserving Curve Fitting Procedure Based On Local Piecewise-Linear Kernel Estimation

It is known that the fitted regression function based on conventional local smoothing procedures is not statistically consistent at jump positions of the true regression function. In this article, a curve-fitting procedure based on local piecewise-linear kernel estimation is suggested. In a neighborhood of a given point, a piecewise-linear function with a possible jump at the given point is fit...