Browsing by Author "Rossi, A."

Now showing 1 - 8 of 8
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    Global phylogeography and ancient evolution of the widespread human gut virus crAssphage
    (2019) Edwards, R.A.; Vega, A.A.; Norman, H.M.; Ohaeri, M.; Levi, K.; Dinsdale, E.A.; Cinek, O.; Aziz, R.K.; McNair, K.; De la Iglesia Cabezas, Rodrigo Alonso; Barr, J.J.; Bibby, K.; Brouns, S.J.J.; Cazares, A.; de Jonge, P.A.; Desnues, C.; Munoz, S.L.D.; Fineran, P.C.; Kurilshikov, A.; Lavigne, R.; Mazankova, K.; McCarthy, D.T.; Nobrega, F.L.; Munoz, A.R.; Tapia, G.; Trefault Carrillo, Nicole Natalie; Tyakht, A.V.; Vinuesa, P.; Wagemans, J.; Zhernakova, A.; Aarestrup, F.M.; Ahmadov, G.; Alassaf, A.; Anton, J.; Asangba, A.; Billings, E.K.; Cantu, V.A.; Carlton, J.M.; Cazares, D.; Cho, G.S.; Condeff, T.; Cortes, P.; Cranfield, M.; Cuevas, D.A.; Decewicz, P.; Doane, M.P.; Dominy, N.J.; Dziewit, L.; Elwasila, B.M.; Eren, A.M.; Franz, C.; Fu, J.Y.; Garcia-Aljaro, C.; Ghedin, E.; Gulino, K.M.; Haggerty, J.M.; Head, S.R.; Hendriksen, R.S.; Hill, C.; Hyoty, H.; Ilina, E.N.; Irwin, M.T.; Jeffries, T.C.; Jofre, J.; Junge, R.E.; Kelley, S.T.; Mirzaei, M.K.; Kowalewski, M.; Kumaresan, D.; Leigh, S.R.; Lipson, D.; Lisitsyna, E.S.; Llagostera, M.; Maritz, J.M.; Marr, L.C.; McCann, A.; Molshanski-Mor, S.; Monteiro, S.; Moreira-Grez, B.; Morris, M.; Mugisha, L.; Muniesa, M.; Neve, H.; Nguyen, N.P.; Nigro, O.D.; Nilsson, A.S.; O'Connell, T.; Odeh, R.; Oliver, A.; Piuri, M.; Prussin, A.J.; Qimron, U.; Quan, Z.X.; Rainetova, P.; Ramirez-Rojas, A.; Raya, R.; Reasor, K.; Rice, G.A.O.; Rossi, A.; Santos, R.; Shimashita, J.; Stachler, E.N.; Stene, L.C.; Strain, R.; Stumpf, R.; Torres, P.J.; Twaddle, A.; Ibekwe, M.U.; Villagra, N.; Wandro, S.; White, B.; Whiteley, A.; Whiteson, K.L.; Wijmenga, C.; Zambrano, M.M.; Zschach, H.; Dutilh, B.E.
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    Identifying the host galaxy of the short GRB 100628A
    (EDP SCIENCES S A, 2015) Guelbenzu, A. Nicuesa; Klose, S.; Palazzi, E.; Greiner, J.; Michalowski, M. J.; Kann, D. A.; Hunt, L. K.; Malesani, D.; Rossi, A.; Savaglio, S.; Schulze, S.; Xu, D.; Afonso, P. M. J.; Elliott, J.; Ferrero, P.; Filgas, R.; Hartmann, D. H.; Kruehler, T.; Knust, F.; Masetti, N.; Olivares E, F.; Rau, A.; Schady, P.; Schmidl, S.; Tanga, M.; Updike, A. C.; Varela, K.
    We report on the results of a comprehensive observing campaign to reveal the host galaxy of the short GRB 100628A. This burst was followed by a faint X-ray afterglow but no optical counterpart was discovered. However, inside the X-ray error circle a potential host galaxy at a redshift of z = 0.102 was soon reported in the literature. If this system is the host, then GRB 100628A was the cosmologically most nearby unambiguous short burst with a measured redshift so far. We used the multi-colour imager GROND at the ESO/La Silla MPG 2.2 in telescope. ESO/VLT spectroscopy, and deep Australia Telescope Compact Array (ATCA) radio-continuum observations together with publicly available Gemini imaging data to study the putative host and the galaxies in the field of GRB 100628A. We confirm that inside the X-ray error circle the most probable host-galaxy candidate is the morphologically disturbed, interacting galaxy system at z = 0.102. The interacting galaxies are connected by a several kpc long tidal stream, which our VLT/FORS2 spectroscopy reveals strong emission lines of [O II] [O III], H alpha and H beta, characteristic for the class of extreme emission-line galaxies and indicative of ongoing star formation. The latter leaves open the possibility that the ORB progenitor was a member of a young stellar population. However, we indentify a second host-galaxy candidate slightly outside the X-ray error circle. It is a radio-bright, luminous elliptical galaxy at a redshift z = 0.311. With a K-band luminosity of 2 x 10(11) L-circle dot this galaxy resembles the probable giant elliptical host of the first well-localized short burst. GRB 050509B. If this is the host, then the progenitor of GRB 100628A was a member of an old stellar population.
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    Presurgical evaluation of basal cell carcinoma using combined reflectance confocal microscopy-optical coherence tomography : A prospective study
    (2020) Aleissa, S.; Navarrete Dechent, Cristián Patricio; Cordova, M.; Sahu, A.; Dusza, S. W.; Phillips, W.; Rossi, A.; Lee, E.; Nehal, K. S.
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    Reflectance confocal microscopy-guided carbon dioxide laser ablation of low-risk basal cell carcinomas : a prospective study
    (2019) Navarrete Dechent, Cristián Patricio; Córdova, M.; Liopyris, K.; Yelamos, O.; Aleissa, S.; Hibler, B.; Sierra, H.; Sahu, A.; Blank, N.; Rajadhyaksha, M.; Rossi, A.
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    Squamous Cell Carcinoma In Situ With Occult Invasion: a Tertiary Care Institutional Experience
    (2019) Newsom, E.; Connolly, K.; Phillips, W.; Lee, E.; Rossi, A.; Navarrete Dechent, Cristián Patricio; Busam, K.; Dusza, S. W.; Nehal, K.; Newsom, E.; Connolly, K.; Phillips, W.; Lee, E.; Rossi, A.; Navarrete Dechent, Cristián Patricio; Busam, K.; Dusza, S. W.; Nehal, K.
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    The 80 Ms follow-up of the X-ray afterglow of GRB 130427A challenges the standard forward shock model
    (OXFORD UNIV PRESS, 2016) De Pasquale, M.; Page, M. J.; Kann, D. A.; Oates, S. R.; Schulze, S.; Zhang, B.; Cano, Z.; Gendre, B.; Malesani, D.; Rossi, A.; Troja, E.; Piro, L.; Boer, M.; Stratta, G.; Gehrels, N.
    GRB 130427A was the brightest gamma-ray burst detected in the last 30 yr. With an equivalent isotropic energy output of 8.5 x 10(53) erg and redshift z = 0.34, it uniquely combined very high energetics with a relative proximity to Earth. As a consequence, its X-ray afterglow has been detected by sensitive X-ray observatories such as XMM-Newton and Chandra for a record-breaking baseline longer than 80 million seconds. We present the X-ray light curve of this event over such an interval. The light curve shows a simple power-law decay with a slope alpha = 1.309 +/- 0.007 over more than three decades in time (47 ks-83 Ms). We discuss the consequences of this result for a few models proposed so far to interpret GRB 130427A, and more in general the significance of this outcome in the context of the standard forward shock model. We find that this model has difficulty in explaining our data, in both cases of constant density and stellar-wind circumburst media, and requires far-fetched values for the physical parameters involved.
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    The optical/NIR afterglow of GRB 111209A: Complex yet not unprecedented
    (2018) Kann, D. A.; Schady, P.; Olivares, E. F.; Klose, S.; Rossi, A.; Perley, D. A.; Zhang, B.; Kruehler, T.; Greiner, J.; Guelbenzu, A. Nicuesa; Elliott, J.; Knust, F.; Cano, Z.; Filgas, R.; Pian, E.; Mazzali, P.; Fynbo, J. P. U.; Leloudas, G.; Afonso, P. M. J.; Delvaux, C.; Graham, J. F.; Rau, A.; Schmidl, S.; Schulze, S.; Tanga, M.; Updike, A. C.; Varela, K.
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    VLT/X-Shooter emission-line spectroscopy of 96 gamma-ray-burst-selected galaxies at 0.1 < z < 3.6
    (EDP SCIENCES S A, 2015) Kruehler, T.; Malesani, D.; Fynbo, J. P. U.; Hartoog, O. E.; Hjorth, J.; Jakobsson, P.; Perley, D. A.; Rossi, A.; Schady, P.; Schulze, S.; Tanvir, N. R.; Vergani, S. D.; Wiersema, K.; Afonso, P. M. J.; Bolmer, J.; Cano, Z.; Covino, S.; D'Elia, V.; de Ugarte Postigo, A.; Filgas, R.; Friis, M.; Graham, J. F.; Greiner, J.; Goldoni, P.; Gomboc, A.; Hammer, F.; Japelj, J.; Kann, D. A.; Kaper, L.; Klose, S.; Levan, A. J.; Leloudas, G.; Milvang Jensen, B.; Guelbenzu, A. Nicuesa; Palazzi, E.; Pian, E.; Piranomonte, S.; Sanchez Ramirez, R.; Savaglio, S.; Selsing, J.; Tagliaferri, G.; Vreeswijk, P. M.; Watson, D. J.; Xu, D.
    We present data and initial results from VLT/X-Shooter emission-line spectroscopy of 96 galaxies selected by long gamma-ray bursts (GRBs) at 0.1 < z < 3.6, the largest sample of GRB host spectra available to date. Most of our GRBs were detected by Swift and 76% are at 0.5 < z < 2.5 with a median z(med) similar to 1.6. Based on Balmer and/or forbidden lines of oxygen, nitrogen, and neon, we measure systemic redshifts, star formation rates (SFR), visual attenuations (A(V)), oxygen abundances (12 + log(O/H)), and emission-line widths (sigma). We study GRB hosts up to z similar to 3.5 and find a strong change in their typical physical properties with redshift. The median SFR of our GRB hosts increases from SFRmed similar to 0.6 M circle dot yr(-1) at z similar to 0.6 up to SFRmed similar to 15 M circle dot yr(-1) at z similar to 2. A higher ratio of [O III]/[O II] at higher redshifts leads to an increasing distance of GRB-selected galaxies to the locus of local galaxies in the Baldwin-Phillips-Terlevich diagram. There is weak evidence for a redshift evolution in A(V) and similar to, with the highest values seen at z similar to 1.5 (A(V)) or z similar to 2 (sigma). Oxygen abundances of the galaxies are distributed between 12 + log(O/H) = 7.9 and 12 + log(O/H) = 9.0 with a median 12 + log(O/H)(med) similar to 8.5. The fraction of GRB-selected galaxies with super-solar metallicities is similar to 20% at z < 1 in the adopted metallicity scale. This is significantly less than the fraction of total star formation in similar galaxies, illustrating that GRBs are scarce in high metallicity environments. At z similar to 3, sensitivity limits us to probing only the most luminous GRB hosts for which we derive metallicities of Z less than or similar to 0.5 Z circle dot. Together with a high incidence of Z similar to 0.5 Z circle dot galaxies at z similar to 1.5, this indicates that a metallicity dependence at low redshift will not be dominant at z similar to 3. Significant correlations exist between the hosts' physical properties. Oxygen abundance, for example, relates to A(V) (12 + log(O/H) proportional to 0.17 A(V)), line width (12 + log(O/H) proportional to sigma(0.6)), and SFR (12 + log(O/H) proportional to SFR0.2). In the last two cases, the normalization of the relations shift to lower metallicities at z > 2 by similar to 0.4 dex. These properties of GRB hosts and their evolution with redshift can be understood in a cosmological context of star-forming galaxies and a picture in which the hosts' properties at low redshift are influenced by the tendency of GRBs to avoid the most metal-rich environments.