Herschel-ATLAS: Blazars in the science demonstration phase field

To investigate the poorly constrained sub-mm counts and spectral properties of blazars we searched for these in the Herschel-ATLAS (H-ATLAS) science demonstration phase (SDP) survey catalog.

We cross-matched 500 μm sources brighter than 50 mJy with the FIRST radio catalogue. We found two blazars, both previously known. Our study is among the first blind blazar searches at sub-mm wavelengths, i.e., in the spectral regime where little is still known about the blazar SEDs, but where the synchrotron peak of the most luminous blazars is expected to occur. Our early results are consistent with educated extrapolations of lower frequency counts and question indications of substantial spectral curvature downwards and of spectral upturns at mm wavelengths. One of the two blazars is identified with a Fermi/LAT γ-ray source and a WMAP source. The physical parameters of the two blazars are briefly discussed. These observations demonstrate that the H-ATLAS survey will provide key information about the physics of blazars and their contribution to sub-mm counts

Mesozooplankton species distribution in the NW and N Iberian shelf during spring 2004: Relationship with frontal structures.

We have analysed the mesozooplankton community structure in the southern Bay of Biscay shelf and its relationship with the hydrographic conditions during spring 2004. According to thermohaline characteristics, we observed two frontal zones of distinct origin along the shelf (around 7° and 3°W), that allowed us to differentiate three different hydrographic domains. The westernmost part of the shelf (WC), defined by the presence of relatively warm and salty water related to the presence of the Iberian Poleward Current (IPC), the easternmost region (EC), characterized by colder and fresher water and subject to the influence of freshwater inputs from the Adour river in the French coast, and a region in the Central Cantabrian Sea (CC), where thermohaline characteristics were intermediate between these two extremes. The mixing layer depth (MLD) regime in these areas was also different: theWCregion was characterized by a mixed water column, whereas in the EC region the river discharges produces stratification of the upper meters of the water column (b10 m); in the CC region, we found a distinct vertical mixing regime that separated coastal (stratification) from shelf (mixed water column) stations, giving rise to a notorious across-shelf front. We found a good match between the aforesaid hydrographic regions and the distribution of mesozooplankton species composition and community assemblages: the Mantel correlation between physical variables and mesozooplankton distribution was highly significant (n=63, r=0.70, αb0.001). In the WC region, the community was dominated by Paracalanus parvus, Oithona helgolandica, Acartia clausi and Clausocalanus pergens, while in the EC region the most dominant species were Noctiluca scintillans, Oncaea media and Temora longicornis. The CC region showed similar composition of copepods than the WC region, but larvaceans (Oikopleura spp. and Fritillaria spp.) were more abundant in the CC region than in the WC region. Within each zone, the relative abundances of the dominant species differed between coastal and shelf locations.SARDYN EUproject (QLRT-2001-00818) Consejería de Educación y Cultura del Principado de Asturias’ (FICYT)

A multifrequency method based on the Matched Multifilter for the detection of point sources in CMB maps

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. To make this, we simulate realistic and non-realistic flat patches of the sky at two frequencies of Planck: 44 and 100 GHz. We filter to detect and estimate the point sources and compare this technique with the monofrequency matched filter in terms of completeness, reliability, flux and spectral index accuracy. The multifrequency method outperforms the matched filter at the two frequencies and in all the studied cases in the work.Comment: 14 pages, 6 figures, 1 tabl

Hydrographic conditions and mesozooplankton species distribution in the Bay of Biscay shelf during spring 2004

Mesozooplankton community structure on the southern Bay of Biscay shelf and its relationship with environmental conditions was analysed during spring 2004. According to thermohaline characteristics, we observed two frontal zones along the shelf (around 7° and 3°W) that gave rise to three distinct hydrographic regions. The westernmost part of the shelf (WC), defined by the presence of relatively warm and salty water related to the presence of the Iberian Poleward Current (IPC), the easternmost region (EC), characterised by colder and fresher water, and a region in the Central Cantabrian Sea (CC) with thermohaline characteristics in between these two extremes. Besides, a clear coastal-offshore pattern was found in relation to the mixed layer depth (MLD). We observed a good agreement between the aforesaid hydrographic regions and the distribution of zooplankton species. In the WC region, the community structure was dominated by Paracalanus parvus, Oithona helgolandica, Acartia clausii and Clausocalanus pergens, while in the EC region the most dominant species were Noctiluca scintillans and Oncaea media. The CC region showed similar composition of copepods than the WC region but larvaceans (Oikopleura and Fritilaria) were also abundant. Superimposed to this along-shelf pattern, relative abundances differed also between coastal and shelf stations.SARDYN EU –project (QLRT-2001-00818

Methodological refinement of the submillimeter galaxy magnification bias. Paper I: cross-correlation function measurements

The measurement of the cross-correlation function is crucial to assess magnification bias in galaxy surveys. Previous works used mini-tile subsampling, but accurately determining the integral constraint (IC) correction for unbiased estimation is challenging due to various factors. We present a new methodology for estimating the cross-correlation function, utilizing full field area and reducing statistical uncertainty. Covariance matrices were estimated by dividing each field into at least five patches using a k-mean clustering algorithm. Robustness was assessed by comparing spectroscopic and photometric lens samples, yielding compatible results. Cross-correlation and auto-correlation analyses in the GAMA fields revealed a stronger signal in GAMA15, likely due to rare large-scale structure combinations. Our findings highlight the robustness of the new methodology and suggest sample-specific effects. Subsequent papers in this series will explore other aspects of magnification bias and address potential biases from the GAMA15 signal on cosmological parameter constraints.Comment: This work is the first one of a three-paper serie. 14 pages, 9 figures, submitted for publication by A&

Methodological refinement of the submillimeter galaxy magnification bias. Paper III: cosmological analysis with tomography

This paper is the third in a series on submillimeter galaxy magnification bias, focusing on the tomographic scenario. It refines the methodology used to constrain the halo occupation distribution model and cosmological parameters within a flat $\Lambda$CDM model, using updated data. The study aims to optimize CPU time, explore strategies for analyzing different redshift bins, and assess the impact of excluding the GAMA15 field. The tomographic approach involves dividing the redshift range into bins and analyzing cross-correlation measurements between submillimeter and foreground galaxies. The results show good agreement between the mean-redshift and full model cases, with an increase in the minimum mass of lenses at higher redshifts. The inferred cosmological parameters have narrower posterior distributions, indicating reduced measurement uncertainties compared to previous studies. Excluding the GAMA15 field reduces the cross-correlation signal, suggesting sample variance within the large-scale structure. Extending the redshift range improves robustness against sample variance and produces similar but tighter constraints. The study highlights the importance of sample variance and redshift binning in tomographic analyses, and suggests using additional wide-area fields and updated foreground catalogues for more effective implementation.Comment: This work is the third of a series of three. 17 pages and 19 figure. submitted to A&