8 research outputs found
Bayesian inference methodology for Primordial Power Spectrum reconstructions from Large Scale Structure
We use Bayesian inference and nested sampling to develop a non-parametric
method to reconstruct the primordial power spectrum from
Large Scale Structure (LSS) data. The performance of the method is studied by
applying it to simulations of the clustering of two different object
catalogues, low- (ELGs) and high- (QSOs), and considering two different
photometric errors. These object clusterings are derived from different
templates of the primordial power spectrum motivated by models of inflation:
the Standard Model power law characterized by the two parameters and
; a local feature template; and a global oscillatory template. Our
reconstruction method involves sampling knots in the log
plane. We use two statistical tests to examine the
reconstructions for signs of primordial features: a global test comparing the
evidences and a novel local test quantifying the power of the hypothesis test
between the power law model and the marginalized probability over model.
The method shows good performance in all scenarios considered. In particular,
the tests show no feature detection for the SM. The method is able to detect
power spectrum deviations at a level of for all considered
features, combining either the low- or the high- redshift bins. Other
scenarios with different redshift bins, photometric errors, feature amplitudes
and detection levels are also discussed. In addition, we include a first
application to real data from the Sloan Digital Sky Survey Luminous Red Galaxy
Data Release 4 (SDSS LRG 04), finding no preference for deviations from the
primordial power law. The method is flexible, model independent, and suitable
for its application to existing and future LSS catalogues.Comment: 39 pages, 21 figures, submitted to JCA
Searching for features in the primordial power spectrum with J-PAS
Trabajo presentado al J-PAS Collaboration Meeting, celebrado online el 8 de febrero de 2021.Peer reviewe
Primordial Power Spectrum reconstruction through non-parametric Bayesian modelin gof LSS catalogues
Trabajo presentado al J-PAS Theory Working Group Meeting, celebrado online el 10 de diciembre de 2021.Peer reviewe
Estudio del estado nutricional de los ancianos de Cantabria Study of the nutritional status of elders in Cantabria
IntroducciĂłn: El envejecimiento de la poblaciĂłn representa uno de los retos mĂĄs importantes desde el punto de vista biosanitario. Objetivo: Valorar el estado nutricional de las personas de 65 y mĂĄs años de Cantabria. MĂ©todos: Un total de 1605 personas fueron evaluadas por medio del MNA; a) en atenciĂłn primaria (59,9% en la consulta y 4,7% en domicilios) y, b) en residencias de ancianos (35,4%). Resultados: La puntuaciĂłn nutricional (PN) obtenida de la suma de los Ătems del MNA fue 23,4 ± 4,1 para las mujeres y 24,4 ± 4 en los varones (p Introduction: Population ageing is a main concern under the biosanitary point of view. Aim: To assess the nutritional status of people 65 year-old and older in Cantabria (Spain) Method: A total of 1605 persons were studied by means of the MNA (Mini Nutritional Assessment); a) by primary care (59.9% in the unit, and 4.7% at home) and, b) in nursing homes (35.4%). Results: Nutritional score (NS) was 23.4 ± 4.1 for women and 24.4 ± 4 in males (p < 0.001). We emphasize the fact that 22.3% of people studied in the nursing homes were malnourished or at risk of malnutrition, compared with 14.2% of those studied at the unit, and only 3.3% of the home visited elders. The correlation between the value of the NS and the subjective estimation of nutrition status showed a high value (0.65). We emphasize the negative correlation (-0.53) between BNI value and the incidence of skin lesions. Conclusion: Our results highlight the importance of identifying malnutrition or its risk in elders in order to prevent the negative consequences of this deficiency
The miniJPAS survey: a preview of the Universe in 56 colours
International audienceThe Javalambre-Physics of the Accelerating Universe Astrophysical Survey (J-PAS) will soon start to scan thousands of square degrees of the northern extragalactic sky with a unique set of optical filters from a dedicated m telescope, JST, at the Javalambre Astrophysical Observatory. Before the arrival of the final instrument (a 1.2 Gpixels, 4.2deg field-of-view camera), the JST was equipped with an interim camera (JPAS-Pathfinder), composed of one CCD with a 0.3deg field-of-view and resolution of 0.23 arcsec pixel. To demonstrate the scientific potential of J-PAS, with the JPAS-Pathfinder camera we carried out a survey on the AEGIS field (along the Extended Groth Strip), dubbed miniJPAS. We observed a total of deg, with the J-PAS filters, which include narrow band (NB, Angstrom) and two broader filters extending to the UV and the near-infrared, complemented by the SDSS broad band (BB) filters. In this paper we present the miniJPAS data set, the details of the catalogues and data access, and illustrate the scientific potential of our multi-band data. The data surpass the target depths originally planned for J-PAS, reaching between and for the NB filters and up to for the BB filters ( in a ~arcsec aperture). The miniJPAS primary catalogue contains more than sources extracted in the detection band with forced photometry in all other bands. We estimate the catalogue to be complete up to for point-like sources and up to for extended sources. Photometric redshifts reach subpercent precision for all sources up to , and a precision of % for about half of the sample. (Abridged
The miniJPAS survey: A preview of the Universe in 56 colors
International audienceThe Javalambre-Physics of the Accelerating Universe Astrophysical Survey (J-PAS) will scan thousands of square degrees of the northern sky with a unique set of 56 filters using the dedicated 2.55 m Javalambre Survey Telescope (JST) at the Javalambre Astrophysical Observatory. Prior to the installation of the main camera (4.2âdeg2 field-of-view with 1.2 Gpixels), the JST was equipped with the JPAS-Pathfinder, a one CCD camera with a 0.3âdeg2 field-of-view and plate scale of 0.23 arcsec pixelâ1. To demonstrate the scientific potential of J-PAS, the JPAS-Pathfinder camera was used to perform miniJPAS, a âŒ1 deg2 survey of the AEGIS field (along the Extended Groth Strip). The field was observed with the 56 J-PAS filters, which include 54 narrow band (FWHMââŒâ145 Ă
) and two broader filters extending to the UV and the near-infrared, complemented by the u,âg,âr,âi SDSS broad band filters. In this miniJPAS survey overview paper, we present the miniJPAS data set (images and catalogs), as we highlight key aspects and applications of these unique spectro-photometric data and describe how to access the public data products. The data parameters reach depths of magABâââ22â23.5 in the 54 narrow band filters and up to 24 in the broader filters (5Ï in a 3âł aperture). The miniJPAS primary catalog contains more than 64â000 sources detected in the r band and with matched photometry in all other bands. This catalog is 99% complete at râ=â23.6 (râ=â22.7) mag for point-like (extended) sources. We show that our photometric redshifts have an accuracy better than 1% for all sources up to râ=â22.5, and a precision of â€0.3% for a subset consisting of about half of the sample. On this basis, we outline several scientific applications of our data, including the study of spatially-resolved stellar populations of nearby galaxies, the analysis of the large scale structure up to zââŒâ0.9, and the detection of large numbers of clusters and groups. Sub-percent redshift precision can also be reached for quasars, allowing for the study of the large-scale structure to be pushed to zâ>â2. The miniJPAS survey demonstrates the capability of the J-PAS filter system to accurately characterize a broad variety of sources and paves the way for the upcoming arrival of J-PAS, which will multiply this data by three orders of magnitude.Key words: surveys / techniques: photometric / astronomical databases: miscellaneous / stars: general / galaxies: general / cosmology: observationsâ miniJPAS data and associated value added catalogs are publicly available http://archive.cefca.es/catalogues/minijpas-pdr20191
The miniJPAS survey: A preview of the Universe in 56 colors
The Javalambre-Physics of the Accelerating Universe Astrophysical Survey (J-PAS) will scan thousands of square degrees of the northern sky with a unique set of 56 filters using the dedicated 2.55 m Javalambre Survey Telescope (JST) at the Javalambre Astrophysical Observatory. Prior to the installation of the main camera (4.2âdeg2 field-of-view with 1.2 Gpixels), the JST was equipped with the JPAS-Pathfinder, a one CCD camera with a 0.3âdeg2 field-of-view and plate scale of 0.23 arcsec pixelâ1. To demonstrate the scientific potential of J-PAS, the JPAS-Pathfinder camera was used to perform miniJPAS, a âŒ1 deg2 survey of the AEGIS field (along the Extended Groth Strip). The field was observed with the 56 J-PAS filters, which include 54 narrow band (FWHMââŒâ145 Ă
) and two broader filters extending to the UV and the near-infrared, complemented by the u,âg,âr,âi SDSS broad band filters. In this miniJPAS survey overview paper, we present the miniJPAS data set (images and catalogs), as we highlight key aspects and applications of these unique spectro-photometric data and describe how to access the public data products. The data parameters reach depths of magABâââ22â23.5 in the 54 narrow band filters and up to 24 in the broader filters (5Ï in a 3âł aperture). The miniJPAS primary catalog contains more than 64â000 sources detected in the r band and with matched photometry in all other bands. This catalog is 99% complete at râ=â23.6 (râ=â22.7) mag for point-like (extended) sources. We show that our photometric redshifts have an accuracy better than 1% for all sources up to râ=â22.5, and a precision of â€0.3% for a subset consisting of about half of the sample. On this basis, we outline several scientific applications of our data, including the study of spatially-resolved stellar populations of nearby galaxies, the analysis of the large scale structure up to zââŒâ0.9, and the detection of large numbers of clusters and groups. Sub-percent redshift precision can also be reached for quasars, allowing for the study of the large-scale structure to be pushed to zâ>â2. The miniJPAS survey demonstrates the capability of the J-PAS filter system to accurately characterize a broad variety of sources and paves the way for the upcoming arrival of J-PAS, which will multiply this data by three orders of magnitude