Browsing by Author "Conversi, L."

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    HerMES: CANDIDATE HIGH-REDSHIFT GALAXIES DISCOVERED WITH HERSCHEL/SPIRE
    (2014) Dowell, C. Darren; Conley, A.; Glenn, J.; Arumugam, V.; Asboth, V.; Aussel, H.; Bertoldi, F.; Bethermin, M.; Bock, J.; Boselli, A.; Bridge, C.; Buat, V.; Burgarella, D.; Cabrera-Lavers, A.; Casey, C. M.; Chapman, S. C.; Clements, D. L.; Conversi, L.; Cooray, A.; Dannerbauer, H.; De Bernardis, F.; Ellsworth-Bowers, T. P.; Farrah, D.; Franceschini, A.; Griffin, M.; Gurwell, M. A.; Halpern, M.; Hatziminaoglou, E.; Heinis, S.; Ibar, E.; Ivison, R. J.; Laporte, N.; Marchetti, L.; Martinez-Navajas, P.; Marsden, G.; Morrison, G. E.; Nguyen, H. T.; O'Halloran, B.; Oliver, S. J.; Omont, A.; Page, M. J.; Papageorgiou, A.; Pearson, C. P.; Petitpas, G.; Perez-Fournon, I.; Pohlen, M.; Riechers, D.; Rigopoulou, D.; Roseboom, I. G.; Rowan-Robinson, M.; Sayers, J.; Schulz, B.; Scott, Douglas; Seymour, N.; Shupe, D. L.; Smith, A. J.; Streblyanska, A.; Symeonidis, M.; Vaccari, M.; Valtchanov, I.; Vieira, J. D.; Viero, M.; Wang, L.; Wardlow, J.; Xu, C. K.; Zemcov, M.
    We present a method for selecting z > 4 dusty, star-forming galaxies (DSFGs) using Herschel/Spectral and Photometric Imaging Receiver 250/350/500 mu m flux densities to search for red sources. We apply this method to 21 deg(2) of data from the HerMES survey to produce a catalog of 38 high-z candidates. Follow-up of the first five of these sources confirms that this method is efficient at selecting high-z DSFGs, with 4/5 at z = 4.3-6.3 (and the remaining source at z = 3.4), and that they are some of the most luminous dusty sources known. Comparison with previous DSFG samples, mostly selected at longer wavelengths (e. g., 850 mu m) and in single-band surveys, shows that our method is much more efficient at selecting high-z DSFGs, in the sense that a much larger fraction are at z > 3. Correcting for the selection completeness and purity, we find that the number of bright (S-500 (mu m) >= 30 mJy), red Herschel sources is 3.3 +/- 0.8 deg(-2). This is much higher than the number predicted by current models, suggesting that the DSFG population extends to higher redshifts than previously believed. If the shape of the luminosity function for high-z DSFGs is similar to that at z similar to 2, rest-frame UV based studies may be missing a significant component of the star formation density at z = 4-6, even after correction for extinction.
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    HerMES: COSMIC INFRARED BACKGROUND ANISOTROPIES AND THE CLUSTERING OF DUSTY STAR-FORMING GALAXIES
    (2013) Viero, M. P.; Wang, L.; Zemcov, M.; Addison, G.; Amblard, A.; Arumugam, V.; Aussel, H.; Bethermin, M.; Bock, J.; Boselli, A.; Buat, V.; Burgarella, D.; Casey, C. M.; Clements, D. L.; Conley, A.; Conversi, L.; Cooray, A.; De Zotti, G.; Dowell, C. D.; Farrah, D.; Franceschini, A.; Glenn, J.; Griffin, M.; Hatziminaoglou, E.; Heinis, S.; Ibar, E.; Ivison, R. J.; Lagache, G.; Levenson, L.; Marchetti, L.; Marsden, G.; Nguyen, H. T.; O'Halloran, B.; Oliver, S. J.; Omont, A.; Page, M. J.; Papageorgiou, A.; Pearson, C. P.; Perez-Fournon, I.; Pohlen, M.; Rigopoulou, D.; Roseboom, I. G.; Rowan-Robinson, M.; Schulz, B.; Scott, D.; Seymour, N.; Shupe, D. L.; Smith, A. J.; Symeonidis, M.; Vaccari, M.; Valtchanov, I.; Vieira, J. D.; Wardlow, J.; Xu, C. K.
    We present measurements of the auto-and cross-frequency power spectra of the cosmic infrared background (CIB) at 250, 350, and 500 mu m (1200, 860, and 600 GHz) from observations totaling similar to 70 deg(2) made with the SPIRE instrument aboard the Herschel Space Observatory. We measure a fractional anisotropy delta I/I = 14% +/- 4%, detecting signatures arising from the clustering of dusty star-forming galaxies in both the linear (2-halo) and nonlinear (1-halo) regimes; and that the transition from the 2- to 1-halo terms, below which power originates predominantly from multiple galaxies within dark matter halos, occurs at k(theta) similar to 0.10-0.12 arcmin(-1) (l similar to 2160-2380), from 250 to 500 mu m. New to this paper is clear evidence of a dependence of the Poisson and 1-halo power on the flux-cut level of masked sources-suggesting that some fraction of the more luminous sources occupy more massive halos as satellites, or are possibly close pairs. We measure the cross-correlation power spectra between bands, finding that bands which are farthest apart are the least correlated, as well as hints of a reduction in the correlation between bands when resolved sources are more aggressively masked. In the second part of the paper, we attempt to interpret the measurements in the framework of the halo model. With the aim of fitting simultaneously with one model the power spectra, number counts, and absolute CIB level in all bands, we find that this is achievable by invoking a luminosity-mass relationship, such that the luminosity-to-mass ratio peaks at a particular halo mass scale and declines toward lower and higher mass halos. Our best-fit model finds that the halo mass which is most efficient at hosting star formation in the redshift range of peak star-forming activity, z similar to 1-3, is log( M-peak/M-circle dot) similar to 12.1 +/- 0.5, and that the minimum halo mass to host infrared galaxies is log(Mmin/M-circle dot) similar to 10.1 +/- 0.6.
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    QUBIC VIII: Optical design and performance
    (2022) O'Sullivan, C.; De Petris, M.; Amico, G.; Battistelli, E. S.; de Bernardis, P.; Burke, D.; Buzi, D.; Chapron, C.; Conversi, L.; D'Alessandro, G.; De Leo, M.; Gayer, D.; Grandsire, L.; Hamilton, J-Ch; Marnieros, S.; Masi, S.; Mattei, A.; Mennella, A.; Mousset, L.; Murphy, J. D.; Pelosi, A.; Perciballi, M.; Piat, M.; Scully, S.; Tartari, A.; Torchinsky, S. A.; Voisin, F.; Zannoni, M.; Zullo, A.; Ade, P.; Alberro, J. G.; Almela, A.; Arnaldi, L. H.; Auguste, D.; Aumont, J.; Azzoni, S.; Banfi, S.; Bau, A.; Belier, B.; Bennett, D.; Berge, L.; Bernard, J-Ph; Bersanelli, M.; Bigot-Sazy, M-A; Bonaparte, J.; Bonis, J.; Bunn, E.; Cavaliere, F.; Chanial, P.; Charlassier, R.; Cobos Cerutti, A. C.; Columbro, F.; Coppolecchia, A.; De Gasperis, G.; Dheilly, S.; Duca, C.; Dumoulin, L.; Etchegoyen, A.; Fasciszewski, A.; Ferreyro, L. P.; Fracchia, D.; Franceschet, C.; Gamboa Lerena, M. M.; Ganga, K. M.; Garcia, B.; Garcia Redondo, M. E.; Gaspard, M.; Gervasi, M.; Giard, M.; Gilles, V; Giraud-Heraud, Y.; Gomez Berisso, M.; Gonzalez, M.; Gradziel, M.; Hampel, M. R.; Harari, D.; Henrot-Versille, S.; Incardona, F.; Jules, E.; Kaplan, J.; Kristukat, C.; Lamagna, L.; Loucatos, S.; Louis, T.; Maffei, B.; Marty, W.; May, A.; McCulloch, M.; Mele, L.; Melo, D.; Montier, L.; Mundo, L. M.; Murphy, J. A.; Nati, F.; Olivieri, E.; Oriol, C.; Paiella, A.; Pajot, F.; Passerini, A.; Pastoriza, H.; Perbost, C.; Pezzotta, F.; Piacentini, F.; Piccirillo, L.; Pisano, G.; Platino, M.; Polenta, G.; Prele, D.; Puddu, R.; Rambaud, D.; Rasztocky, E.; Ringegni, P.; Romero, G. E.; Salum, J. M.; Schillaci, A.; Scoccola, C. G.; Spinelli, S.; Stankowiak, G.; Stolpovskiy, M.; Supanitsky, A. D.; Thermeau, J-P; Timbie, P.; Tomasi, M.; Tucker, C.; Tucker, G.; Vigano, D.; Vittorio, N.; Wicek, F.; Wright, M.
    The Q and U Bolometric Interferometer for Cosmology (QUBIC) is a ground-based experiment that aims to detect B-mode polarization anisotropies [1] in the CMB at angular scales around the l similar or equal to 100 recombination peak. Systematic errors make ground-based observations of B modes at millimetre wavelengths very challenging and QUBIC mitigates these problems in a somewhat complementary way to other existing or planned experiments using the novel technique of bolometric interferometry. This technique takes advantage of the sensitivity of an imager and the systematic error control of an interferometer. A cold reflective optical combiner superimposes the re-emitted beams from 400 aperture feedhorns on two focal planes. A shielding system composed of a fixed groundshield, and a forebaffle that moves with the instrument, limits the impact of local contaminants. The modelling, design, manufacturing and preliminary measurements of the optical components are described in this paper.