Zobrazeno 1 - 10
of 505
pro vyhledávání: '"Sanz, J. L."'
Autor:
Lanz, L. F., Herranz, D., López-Caniego, M., González-Nuevo, J., de Zotti, G., Massardi, M., Sanz, J. L.
The detection of point sources in Cosmic Microwave Background maps is usually based on a single-frequency approach, whereby maps at each frequency are filtered separately and the spectral information on the sources is derived combining the results at
Externí odkaz:
http://arxiv.org/abs/1110.6877
The detection and flux estimation of point sources in cosmic microwave background (CMB) maps is a very important task in order to clean the maps and also to obtain relevant astrophysical information. In this paper we propose a maximum a posteriori (M
Externí odkaz:
http://arxiv.org/abs/1101.1456
We propose a Bayesian approach to joint source separation and restoration for astrophysical diffuse sources. We constitute a prior statistical model for the source images by using their gradient maps. We assume a t-distribution for the gradient maps
Externí odkaz:
http://arxiv.org/abs/1101.1397
Publikováno v:
IEEE Transactions on Signal Processing, vol. 19, issue 9, 2010, pp. 2357-2368
We propose to model the image differentials of astrophysical source maps by Student's t-distribution and to use them in the Bayesian source separation method as priors. We introduce an efficient Markov Chain Monte Carlo (MCMC) sampling scheme to unmi
Externí odkaz:
http://arxiv.org/abs/1101.1396
We consider a set of M images, whose pixel intensities at a common point can be treated as the components of a M-dimensional vector. We are interested in the estimation of the modulus of such a vector associated to a compact source. For instance, the
Externí odkaz:
http://arxiv.org/abs/1101.0701
Autor:
Vielva, P., Sanz, J. L.
[Abridged] In this paper we explore a local non-linear perturbative model up to third order as a general characterization of the CMB anisotropies. We focus our analysis in large scale anisotropies. At these angular scales, the non-Gaussian descriptio
Externí odkaz:
http://arxiv.org/abs/0910.3196
Autor:
Lopez-Caniego, M., Massardi, M., Gonzalez-Nuevo, J., Lanz, L., Herranz, D., De Zotti, G., Sanz, J. L., Argueso, F.
Publikováno v:
Astrophys.J.705:868-876,2009
The detection of polarized sources in the WMAP 5-year data is a very difficult task. The maps are dominated by instrumental noise and only a handful of sources show up as clear peaks in the Q and U maps. Optimal linear filters applied at the position
Externí odkaz:
http://arxiv.org/abs/0909.4311
In this work we deal with the problem of simultaneous multifrequency detection of extragalactic point sources in maps of the Cosmic Microwave Background. We apply a linear filtering technique that uses spatial information and the cross-power spectrum
Externí odkaz:
http://arxiv.org/abs/0907.0603
Publikováno v:
Mon.Not.Roy.Astron.Soc.395:649-656,2009
Given a set of images, whose pixel values can be considered as the components of a vector, it is interesting to estimate the modulus of such a vector in some localised areas corresponding to a compact signal. For instance, the detection/estimation of
Externí odkaz:
http://arxiv.org/abs/0906.0893
Autor:
Vielva, P., Sanz, J. L.
We present a new method based on the N-point probability distribution (pdf) to study non-Gaussianity in cosmic microwave background (CMB) maps. Likelihood and Bayesian estimation are applied to a local non-linear perturbed model up to third order, ch
Externí odkaz:
http://arxiv.org/abs/0812.1756