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Sökning: WFRF:(Fenech D. M.)

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1.
  • Baldi, R. D., et al. (författare)
  • LeMMINGs III. The e-MERLIN legacy survey of the Palomar sample: Exploring the origin of nuclear radio emission in active and inactive galaxies through the [O iii] - Radio connection
  • 2021
  • Ingår i: Monthly Notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 508:2, s. 2019-2038
  • Tidskriftsartikel (refereegranskat)abstract
    • What determines the nuclear radio emission in local galaxies? To address this question, we combine optical [O iii] line emission, robust black hole (BH) mass estimates, and high-resolution e-MERLIN 1.5-GHz data, from the LeMMINGs survey, of a statistically complete sample of 280 nearby optically active (LINER and Seyfert) and inactive [H ii and absorption line galaxies (ALGs)] galaxies. Using [O iii] luminosity (L[O III]) as a proxy for the accretion power, local galaxies follow distinct sequences in the optical-radio planes of BH activity, which suggest different origins of the nuclear radio emission for the optical classes. The 1.5-GHz radio luminosity of their parsec-scale cores (Lcore) is found to scale with BH mass (MBH) and [O iii] luminosity. Below MBH ∼106.5 M⊙, stellar processes from non-jetted H ii galaxies dominate with Lcore ∝ MBH0.61 ± 0.33 and Lcore ∝ L[O III]0.79 ± 0.30. Above MBH ∼106.5 M⊙, accretion-driven processes dominate with Lcore ∝ MBH1.5-1.65 and Lcore ∝ L[O III]0.99-1.31 for active galaxies: radio-quiet/loud LINERs, Seyferts, and jetted H ii galaxies always display (although low) signatures of radio-emitting BH activity, with L1.5 GHz ≳ 1019.8 W Hz-1 and MBH ≳ 107 M⊙, on a broad range of Eddington-scaled accretion rates (m). Radio-quiet and radio-loud LINERs are powered by low-m discs launching sub-relativistic and relativistic jets, respectively. Low-power slow jets and disc/corona winds from moderately high to high-m discs account for the compact and edge-brightened jets of Seyferts, respectively. Jetted H ii galaxies may host weakly active BHs. Fuel-starved BHs and recurrent activity account for ALG properties. In conclusion, specific accretion-ejection states of active BHs determine the radio production and the optical classification of local active galaxies.
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2.
  • Baldi, R. D., et al. (författare)
  • LeMMINGs - I. The eMERLIN legacy survey of nearby galaxies. 1.5-GHz parsec-scale radio structures and cores
  • 2018
  • Ingår i: Monthly Notices of the Royal Astronomical Society. - 0035-8711 .- 1365-2966. ; 476:3, s. 3478-3522
  • Tidskriftsartikel (refereegranskat)abstract
    • We present the first data release of high-resolution (≤0.2 arcsec) 1.5-GHz radio images of 103 nearby galaxies from the Palomar sample, observed with the eMERLIN array, as part of the LeMMINGs survey. This sample includes galaxies which are active (low-ionization nuclear emission-line regions [LINER] and Seyfert) and quiescent (H II galaxies and absorption line galaxies, ALGs), which are reclassified based upon revised emission-line diagrams.We detect radio emission ≳0.2 mJy for 47/103 galaxies (22/34 for LINERS, 4/4 for Seyferts, 16/51 for HII galaxies, and 5/14 for ALGs) with radio sizes typically of ≲100 pc. We identify the radio core position within the radio structures for 41 sources. Half of the sample shows jetted morphologies. The remaining half shows single radio cores or complex morphologies. LINERs show radio structures more core-brightened than Seyferts. Radio luminosities of the sample range from 1032to 1040erg s-1: LINERs and HII galaxies show the highest and lowest radio powers, respectively, while ALGs and Seyferts have intermediate luminosities. We find that radio core luminosities correlate with black hole (BH) mass down to ~107M⊙, but a break emerges at lower masses. Using [OIII] line luminosity as a proxy for the accretion luminosity, active nuclei and jetted HII galaxies follow an optical Fundamental Plane of BH activity, suggesting a common disc-jet relationship. In conclusion, LINER nuclei are the scaled-down version of FR I radio galaxies; Seyferts show less collimated jets; HII galaxies may host weak active BHs and/or nuclear star-forming cores; and recurrent BH activity may account for ALG properties.
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3.
  • Baldi, R. D., et al. (författare)
  • LeMMINGs - II. The e-MERLIN legacy survey of nearby galaxies. The deepest radio view of the Palomar sample on parsec scale
  • 2021
  • Ingår i: Monthly Notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 500:4, s. 4749-4767
  • Tidskriftsartikel (refereegranskat)abstract
    • We present the second data release of high-resolution (≤0.2 arcsec) 1.5-GHz radio images of 177 nearby galaxies from the Palomar sample, observed with the e-MERLIN array, as part of the Legacy e-MERLIN Multi-band Imaging of Nearby Galaxies Sample (LeMMINGs) survey. Together with the 103 targets of the first LeMMINGs data release, this represents a complete sample of 280 local active (LINER and Seyfert) and inactive galaxies (H ii galaxies and absorption line galaxies, ALG). This large program is the deepest radio survey of the local Universe, ≳1017.6 W Hz-1, regardless of the host and nuclear type: we detect radio emission ≳0.25 mJy beam-1 for 125/280 galaxies (44.6 per cent) with sizes of typically ≲100 pc. Of those 125, 106 targets show a core which coincides within 1.2 arcsec with the optical nucleus. Although we observed mostly cores, around one third of the detected galaxies features jetted morphologies. The detected radio core luminosities of the sample range between ∼1034 and 1040 erg s-1. LINERs and Seyferts are the most luminous sources, whereas H ii galaxies are the least. LINERs show FR I-like core-brightened radio structures while Seyferts reveal the highest fraction of symmetric morphologies. The majority of H ii galaxies have single radio core or complex extended structures, which probably conceal a nuclear starburst and/or a weak active nucleus (seven of them show clear jets). ALGs, which are typically found in evolved ellipticals, although the least numerous, exhibit on average the most luminous radio structures, similar to LINERs.
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4.
  • Wain, Louise V, et al. (författare)
  • Genome-wide association analyses for lung function and chronic obstructive pulmonary disease identify new loci and potential druggable targets.
  • 2017
  • Ingår i: Nature Genetics. - : Springer Science and Business Media LLC. - 1061-4036 .- 1546-1718. ; 49:3, s. 416-425
  • Tidskriftsartikel (refereegranskat)abstract
    • Chronic obstructive pulmonary disease (COPD) is characterized by reduced lung function and is the third leading cause of death globally. Through genome-wide association discovery in 48,943 individuals, selected from extremes of the lung function distribution in UK Biobank, and follow-up in 95,375 individuals, we increased the yield of independent signals for lung function from 54 to 97. A genetic risk score was associated with COPD susceptibility (odds ratio per 1 s.d. of the risk score (∼6 alleles) (95% confidence interval) = 1.24 (1.20-1.27), P = 5.05 × 10(-49)), and we observed a 3.7-fold difference in COPD risk between individuals in the highest and lowest genetic risk score deciles in UK Biobank. The 97 signals show enrichment in genes for development, elastic fibers and epigenetic regulation pathways. We highlight targets for drugs and compounds in development for COPD and asthma (genes in the inositol phosphate metabolism pathway and CHRM3) and describe targets for potential drug repositioning from other clinical indications.
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5.
  • Williams, D. R.A., et al. (författare)
  • LeMMINGs - IV. The X-ray properties of a statistically complete sample of the nuclei in active and inactive galaxies from the Palomar sample
  • 2022
  • Ingår i: Monthly Notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 510:4, s. 4909-4928
  • Tidskriftsartikel (refereegranskat)abstract
    • All 280 of the statistically complete Palomar sample of nearby ( < 120 Mpc) galaxies δ> 20 ◦have been observed at 1.5 GHz as part of the LeMMINGs e -MERLIN le gac y surv e y. Here, we present Chandr a X-ray observations of the nuclei of 213 of these galaxies, including a statistically complete sub-set of 113 galaxies in the declination range 40 ◦<δ< 65 ◦. We observed galaxies of all optical spectral types, including 'active' galaxies [e.g. low-ionization nuclear emission line regions (LINERs) and Seyferts] and 'inactive' galaxies like H II galaxies and absorption line galaxies (ALG). The X-ray flux limit of our surv e y is 1.65 ×10 -14 erg s -1 cm -2 (0.3 -10 keV). We detect X-ray emission coincident within 2 arcsec of the nucleus in 150/213 galaxies, including 13/14 Seyferts, 68/77 LINERs, 13/22 ALGs and 56/100 H II galaxies, but cannot completely rule out contamination from non-AGN processes in sources with nuclear luminosities ≲ 10 39 erg s -1 . We construct an X-ray Luminosity function (XLF) and find that the local galaxy XLF, when including all active galactic nucleus (AGN) types, can be represented as a single power law of slope -0.54 ±0.06. The Eddington ratio of the Seyferts is usually 2 -4 decades higher than that of the LINERs, ALGs, and H II galaxies, which are mostly detected with Eddington ratios ≲ 10 -3 . Using [ O III ] line measurements and black hole masses from the literature, we show that LINERs, H II galaxies and ALGs follow similar correlations to low luminosities, suggesting that some 'inactive' galaxies may harbour AGN.
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6.
  • Kaput, J, et al. (författare)
  • The case for strategic international alliances to harness nutritional genomics for public and personal health
  • 2005
  • Ingår i: The British journal of nutrition. - : Cambridge University Press (CUP). - 0007-1145 .- 1475-2662. ; 94:5, s. 623-632
  • Tidskriftsartikel (refereegranskat)abstract
    • Nutrigenomics is the study of how constituents of the diet interact with genes, and their products, to alter phenotype and, conversely, how genes and their products metabolise these constituents into nutrients, antinutrients, and bioactive compounds. Results from molecular and genetic epidemiological studies indicate that dietary unbalance can alter gene–nutrient interactions in ways that increase the risk of developing chronic disease. The interplay of human genetic variation and environmental factors will make identifying causative genes and nutrients a formidable, but not intractable, challenge. We provide specific recommendations for how to best meet this challenge and discuss the need for new methodologies and the use of comprehensive analyses of nutrient–genotype interactions involving large and diverse populations. The objective of the present paper is to stimulate discourse and collaboration among nutrigenomic researchers and stakeholders, a process that will lead to an increase in global health and wellness by reducing health disparities in developed and developing countries.
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7.
  • Beswick, R. J., et al. (författare)
  • SKA studies of nearby galaxies: Star-formation, accretion processes and molecular gas across all environments
  • 2014
  • Ingår i: Proceedings of Science. - 1824-8039.
  • Konferensbidrag (refereegranskat)abstract
    • The SKA will be a transformational instrument in the study of our local Universe. In particular, by virtue of its high sensitivity (both to point sources and diffuse low surface brightness emission), angular resolution and the frequency ranges covered, the SKA will undertake a very wide range of astrophysical research in the field of nearby galaxies. By surveying vast numbers of nearby galaxies of all types with mJy sensitivity and sub-arcsecond angular resolutions at radio wavelengths, the SKA will provide the cornerstone of our understanding of star-formation and accretion activity in the local Universe. In this chapter we outline the key continuum and molecular line science areas where the SKA, both during phase-1 and when it becomes the full SKA, will have a significant scientific impact.
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  • Resultat 1-10 av 15

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