Institute Of Fisica Of Cantabria Csic Uc

Santander, Spain

Institute Of Fisica Of Cantabria Csic Uc

Santander, Spain
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Gonzalez-Nuevo J.,Institute Of Fisica Of Cantabria Csic Uc | Gonzalez-Nuevo J.,International School for Advanced Studies | Lapi A.,International School for Advanced Studies | Lapi A.,University of Rome Tor Vergata | And 26 more authors.
Monthly Notices of the Royal Astronomical Society | Year: 2014

We report a highly significant (>10σ) spatial correlation between galaxies with S350μm ≥ 30 mJy detected in the equatorial fields of the Herschel Astrophysical Terahertz Large Area Survey (H-ATLAS) with estimated redshifts ≳1.5, and Sloan Digital Sky Survey (SDSS) or Galaxy And Mass Assembly (GAMA) galaxies at 0.2 ≤ z ≤ 0.6. The significance of the cross-correlation is much higher than those reported so far for samples with non-overlapping redshift distributions selected in other wavebands. Extensive, realistic simulations of clustered sub-mm galaxies amplified by foreground structures confirm that the cross-correlation can be explained by weak gravitational lensing (μ<2). The simulations also show that the measured amplitude and range of angular scales of the signal are larger than can be accounted for by galaxy-galaxy weak lensing. However, for scales ≲2 arcmin, the signal can be reproduced if SDSS/GAMA galaxies act as signposts of galaxy groups/clusters with halo masses in the range 1013.2-1014.5 M⊙. The signal detected on larger scales appears to reflect the clustering of such haloes. © 2014 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society.

Bourne N.,University of Nottingham | Bourne N.,University of Edinburgh | Maddox S.J.,University of Edinburgh | Maddox S.J.,University of Canterbury | And 13 more authors.
Monthly Notices of the Royal Astronomical Society | Year: 2014

We report an unexpected variation in the positional offset distributions between Herschel-Astrophysical Terahertz Large Area Survey (H-ATLAS) submillimetre (submm) sources and their optical associations, depending on both 250-μm signal-to-noise ratio and 250/350-μm colour. We show that redder and brighter submm sources have optical associations with a broader distribution of positional offsets than would be expected if these offsets were due to random positional errors in the source extraction. The observation can be explained by two possible effects: Either red submm sources trace a more clustered population than blue ones, and their positional errors are increased by confusion, or red submm sources are generally at high redshifts and are frequently associated with low-redshift lensing structures which are identified as false counterparts. We perform various analyses of the data, including the multiplicity of optical associations, the redshift and magnitude distributions in H-ATLAS in comparison to HerMES, and simulations of weak lensing, and we conclude that the effects are most likely to be explained by widespread weak lensing of Herschel-SPIRE sources by foreground structures. This has important consequences for counterpart identification and derived redshift distributions and luminosity functions of submm surveys. © 2014 The Authors.

Negrello M.,National institute for astrophysics | Clemens M.,National institute for astrophysics | Gonzalez-Nuevo J.,Institute Of Fisica Of Cantabria Csic Uc | De Zotti G.,National institute for astrophysics | And 20 more authors.
Monthly Notices of the Royal Astronomical Society | Year: 2013

The Planck Early Release Compact Source Catalogue (ERCSC) has offered the first opportunity to accurately determine the luminosity function of dusty galaxies in the very local Universe (i.e. distances ≲ 100 Mpc), at several (sub-)millimetre wavelengths, using blindly selected samples of low-redshift sources, unaffected by cosmological evolution. This project, however, requires careful consideration of a variety of issues including the choice of the appropriate flux density measurement, the separation of dusty galaxies from radio sources and from Galactic sources, the correction for the CO emission, the effect of density inhomogeneities and more. We present estimates of the local luminosity functions at 857 GHz (350 μm), 545 GHz (550 μm) and 353 GHz (850 μm) extending across the characteristic luminosityL, and a preliminary estimate over a limited luminosity range at 217 GHz (1382 μm). At 850 μm and for luminosities L ≲ L* our results agree with previous estimates, derived from the Submillimeter Common-User Bolometer Array (SCUBA) Local Universe Galaxy Survey, but are higher than the latter at L ≲ L*. We also find good agreement with estimates at 350 and 500 μm based on preliminary Herschel survey data. © 2012 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society.

Kohn S.A.,University of Edinburgh | Kohn S.A.,University of Pennsylvania | Michalowski M.J.,University of Edinburgh | Bourne N.,University of Edinburgh | And 27 more authors.
Monthly Notices of the Royal Astronomical Society | Year: 2015

Gamma-ray bursts (GRBs) are themost energetic phenomena in theUniverse; believed to result from the collapse and subsequent explosion of massive stars. Even though it has profound consequences for our understanding of their nature and selection biases, little is known about the dust properties of the galaxies hosting GRBs. We present analysis of the far-infrared properties of an unbiased sample of 20 BeppoSAX and Swift GRB host galaxies (at an average redshift of z = 3.1) located in the Herschel Astrophysical Terahertz Large Area Survey, the Herschel Virgo Cluster Survey, the Herschel Fornax Cluster Survey, the Herschel Stripe 82 Survey and the Herschel Multi-tiered Extragalactic Survey, totalling 880 deg2, or ~3 per cent of the sky in total. Our sample selection is serendipitous, based only on whether the Xray position of a GRB lies within a large-scale Herschel survey - therefore our sample can be considered completely unbiased. Using deep data at wavelengths of 100-500 μm, we tentatively detected 1 out of 20GRBhosts located in these fields.We constrain their dustmasses and star formation rates (SFRs), and discuss these in the context of recent measurements of submillimetre galaxies and ultraluminous infrared galaxies. The average far-infrared flux of our sample gives an upper limit on SFR of <114 M⊙ yr-1. The detection rate of GRB hosts is consistent with that predicted assuming that GRBs trace the cosmic SFR density in an unbiased way, i.e. that the fraction of GRB hosts with SFR > 500M⊙ yr-1 is consistent with the contribution of such luminous galaxies to the cosmic star formation density. © 2015 The Authors.

Bianchini F.,International School for Advanced Studies | Bianchini F.,National Institute of Nuclear Physics, Italy | Bielewicz P.,International School for Advanced Studies | Lapi A.,International School for Advanced Studies | And 23 more authors.
Astrophysical Journal | Year: 2015

We present the first measurement of the correlation between the map of the cosmic microwave background (CMB) lensing potential derived from the Planck nominal mission data and galaxies detected by the Herschel-ATLAS (H-ATLAS) survey covering about , i.e., about 1.4% of the sky. We reject the hypothesis that there is no correlation between CMB lensing and galaxy detection at asignificance, checking the result by performing a number of null tests. The significance of the detection of the theoretically expected cross-correlation signal is found to be. The galaxy bias parameter, b, derived from a joint analysis of the cross-power spectrum and of the autopower spectrum of the galaxy density contrast is found to be , consistent with earlier estimates for H-ATLAS galaxies at similar redshifts. On the other hand, the amplitude of the cross-correlation is found to be a factor 1.62 ± 0.16 higher than expected from the standard model and also found by cross-correlation analyses with other tracers of the large-scale structure. The enhancement due to lensing magnification can account for only a fraction of the excess cross-correlation signal. We suggest that part of it may be due to an incomplete removal of the contamination of the cosmic infrared background, which includes the H-ATLAS sources we are cross-correlating with. In any case, the highly significant detection reported here using a catalog covering only 1.4% of the sky demonstrates the potential of CMB lensing correlations with submillimeter surveys. © 2015. The American Astronomical Society. All rights reserved.

Heinemeyer S.,Institute Of Fisica Of Cantabria Csic Uc | Mondragon M.,National Autonomous University of Mexico | Zoupanos G.,Max Planck Institute for Physics | Zoupanos G.,Ludwig Maximilians University of Munich
Physics of Particles and Nuclei | Year: 2013

All-loop Finite Unified Theories (FUTs) are very interesting N = 1 supersymmetric Grand Unified Theories (GUTs) realising an old field theory dream, and moreover have a remarkable predictive power due to the required reduction of couplings. The reduction of the dimensionless couplings in N = 1 GUTs is achieved by searching for renormalization group invariant (RGI) relations among them holding beyond the unification scale. Finiteness results from the fact that there exist RGI relations among dimensional couplings that guarantee the vanishing of all beta-functions in certain N = 1 GUTs even to all orders. Additional developments in the soft supersymmetry breaking sector of N = 1 GUTs and FUTs lead to exact RGI relations, i. e. reduction of couplings, in this dimensionful sector of the theory, too. Based on the above theoretical framework phenomenologically consistent FUTs have been constructed. Here we review two FUT models based on the SU(5) gauge group. Confronting their predictions with the top and bottom quark masses and other experimental constraints a light Higgs-boson mass in the range MH ~ 121-126 GeV has been predicted, in striking agreement with the recent experimental results from ATLAS and CMS. Furthermore naturally a relatively heavy s-spectrum emerged with coloured supersymmetric particles above ~1. 5 TeV in agreement with the non-observation of those particles at the LHC. Restricting further the parameter space of the best version of the SU(5) FUT according to the reported accuracy of the Higgs boson mass and B-physics observables we find predictions for the rest of the Higgs masses and the s-spectrum. © 2013 Pleiades Publishing, Ltd.

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