Examinando por Autor "Anguita, Timo"
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Ítem A quasar microlensing light-curve generator for LSST(Oxford University Press, 2020-06-01) Neira, Favio; Anguita, Timo; Vernardos, GeorgiosWe present a tool to generate mock quasar microlensing light curves and sample them according to any observing strategy. An updated treatment of the fixed and random velocity components of observer, lens, and source is used, together with a proper alignment with the external shear defining the magnification map caustic orientation. Our tool produces quantitative results on high magnification events and caustic crossings, which we use to study three lensed quasars known to display microlensing, viz. RX J1131–1231, HE 0230–2130, and Q 2237+0305, as they would be monitored by The Rubin Observatory Legacy Survey of Space and Time (LSST). We conclude that depending on the location on the sky, the lens and source redshift, and the caustic network density, the microlensing variability may deviate significantly than the expected ∼20-yr average time-scale (Mosquera & Kochanek 2011). We estimate that ∼300 high magnification events with Δmag>1 mag could potentially be observed by LSST each year. The duration of the majority of high magnification events is between 10 and 100 d, requiring a very high cadence to capture and resolve them. Uniform LSST observing strategies perform the best in recovering microlensing high magnification events. Our web tool can be extended to any instrument and observing strategy, and is freely available as a service at http://gerlumph.swin.edu.au/tools/lsst generator/, along with all the related code.Ítem Alma spectroscopic survey in the hubble ultra deep field: co luminosity functions and the evolution of the cosmic density of molecular gas(Institute of Physics Publishing, 2016-12) Decarli, Roberto; Walter, Fabian; Aravena, Manuel; Carilli, Chris; Bouwens, Rychard; Da Cunha, Elisabete; Daddi, Emanuele; Ivison, R.J.; Popping, Gergö; Riechers, Dominik; Smail, Ian R.; Swinbank, Mark; Weiss, Axel; Anguita, Timo; Assef, Roberto J.; Bauer, Franz E.; Bell, Eric F.; Bertoldi, Frank; Chapman, Scott; Colina, Luis; Cortes, Paulo C.; Cox, Pierre; Dickinson, Mark; Elbaz, David; Gónzalez-López, Jorge; Ibar, Edo; Infante, Leopoldo; Hodge, Jacqueline; Karim, Alex; Fevre, Olivier Le; Magnelli, Benjamin; Neri, Roberto; Oesch, Pascal; Ota, Kazuaki; Rix, Hans-Walter; Sargent, Mark; Sheth, Kartik; Van Der Wel, Arjen; Van Der Werf, Paul; Wagg, JeffIn this paper we use ASPECS, the ALMA Spectroscopic Survey in the Hubble Ultra Deep Field in band 3 and band 6, to place blind constraints on the CO luminosity function and the evolution of the cosmic molecular gas density as a function of redshift up to z ∼ 4.5. This study is based on galaxies that have been selected solely through their CO emission and not through any other property. In all of the redshift bins the ASPECS measurements reach the predicted “knee” of the CO luminosity function (around 5 × 109 K km s−1 pc2 ). We find clear evidence of an evolution in the CO luminosity function with respect to z ∼ 0, with more CO-luminous galaxies present at z ∼ 2. The observed galaxies at z ∼ 2 also appear more gas-rich than predicted by recent semi analytical models. The comoving cosmic molecular gas density within galaxies as a function of redshift shows a drop by a factor of 3–10 from z ∼ 2 to z ∼ 0 (with significant error bars), and possibly a decline at z > 3. This trend is similar to the observed evolution of the cosmic star formation rate density. The latter therefore appears to be at least partly driven by the increased availability of molecular gas reservoirs at the peak of cosmic star formation (z ∼ 2).Ítem Alma spectroscopic survey in the hubble ultra deep field: survey description(Institute of Physics Publishing, 2016-12) Walter, Fabian; Decarli, Roberto; Aravena, Manuel; Carilli, Chris; Bouwens, Rychard; Cunha, Elisabete Da; Daddi, Emanuele; Ivison, R.J.; Riechers, Dominik; Smail, Ian; Swinbank, Mark; Weiss, Axel; Anguita, Timo; Assef, Roberto; Bacon, Roland; Bauer, Franz; Bell, Eric F.; Bertoldi, Frank; Chapman, Scott; Colina, Luis; Cortes, Paulo C.; Cox, Pierre; Dickinson, Mark; Elbaz, David; Gónzalez-López, Jorge; Ibar, Edo; Inami, Hanae; Infante, Leopoldo; Hodge, Jacqueline; Karim, Alex; Fevre, Olivier Le; Magnelli, Benjamin; Neri, Roberto; Oesch, Pascal; Ota, Kazuaki; Popping, Gergö; Rix, Hans-Walter; Sargent, Mark; Sheth, Kartik; Wel, Arjen Van Der; Werf, Paul Van Der; Wagg, JeffWe present the rationale for and the observational description of ASPECS: the ALMA SPECtroscopic Survey in the Hubble Ultra-Deep Field (UDF), the cosmological deep field that has the deepest multi-wavelength data available. Our overarching goal is to obtain an unbiased census of molecular gas and dust continuum emission in high-redshift (z > 0.5) galaxies. The ∼1′ region covered within the UDF was chosen to overlap with the deepest available imaging from the Hubble Space Telescope. Our ALMA observations consist of full frequency scans in band 3 (84–115 GHz) and band 6 (212–272 GHz) at approximately uniform line sensitivity (LCO¢ ~ 2 × 109 K km s−1 pc2 ), and continuum noise levels of 3.8 μJy beam−1 and 12.7 μJy beam−1 , respectively. The molecular surveys cover the different rotational transitions of the CO molecule, leading to essentially full redshift coverage. The [C II] emission line is also covered at redshifts 6.0 8.0 <Ítem New Constraints on Quasar Broad Absorption and Emission Line Regions from Gravitational Microlensing(Journal, 2017-09) Hutsemékers, Damien; Braibant, Lorraine; Sluse, Dominique; Anguita, Timo; Goosmann, RenéGravitational microlensing is a powerful tool allowing one to probe the structure of quasars on sub-parsec scale. We report recent results, focusing on the broad absorption and emission line regions. In particular microlensing reveals the intrinsic absorption hidden in the P Cygni-type line profiles observed in the broad absorption line quasar H1413+117, as well as the existence of an extended continuum source. In addition, polarization microlensing provides constraints on the scattering region. In the quasar Q2237+030, microlensing differently distorts the Hα and CIV broad emission line profiles, indicating that the low- and high-ionization broad emission lines must originate from regions with distinct kinematical properties. We also present simulations of the effect of microlensing on line profiles considering simple but representative models of the broad emission line region. Comparison of observations to simulations allows us to conclude that the Hα emitting region in Q2237+030 is best represented by a Keplerian disk. © Copyright © 2017 Hutsemékers, Braibant, Sluse, Anguita and Goosmann.Ítem The Impact of Observing Strategy on Cosmological Constraints with LSST(American Astronomical Society, 2022-04-01) Lochner, Michelle; Scolnic, Dan; Almoubayyed, Husni; Anguita, Timo; Awan, Humna; Gawiser, Eric; A Gontcho, Satya Gontcho; Graham, Melissa L.; Gris, Philippe; Huber, Simon; Jha, Saurabh W.; Jones R., Lynne; Kim, Alex G.; Mandelbaum, Rachel; Marshall, Phil; Petrushevska, Tanja; Regnault, Nicolas; Setzer, Christian N.; Suyu, Sherry H.; Yoachim, Peter; Biswas, Rahul; Blaineau, Tristan; Hook, Isobel; Moniez, Marc; Neilsen, Eric; Peiris, Hiranya; Rothchild, Daniel; Stubbs, ChristopherThe generation-defining Vera C. Rubin Observatory will make state-of-the-art measurements of both the static and transient universe through its Legacy Survey for Space and Time (LSST). With such capabilities, it is immensely challenging to optimize the LSST observing strategy across the survey's wide range of science drivers. Many aspects of the LSST observing strategy relevant to the LSST Dark Energy Science Collaboration, such as survey footprint definition, single-visit exposure time, and the cadence of repeat visits in different filters, are yet to be finalized. Here, we present metrics used to assess the impact of observing strategy on the cosmological probes considered most sensitive to survey design; these are large-scale structure, weak lensing, type Ia supernovae, kilonovae, and strong lens systems (as well as photometric redshifts, which enable many of these probes). We evaluate these metrics for over 100 different simulated potential survey designs. Our results show that multiple observing strategy decisions can profoundly impact cosmological constraints with LSST; these include adjusting the survey footprint, ensuring repeat nightly visits are taken in different filters, and enforcing regular cadence. We provide public code for our metrics, which makes them readily available for evaluating further modifications to the survey design. We conclude with a set of recommendations and highlight observing strategy factors that require further research. © 2022. The Author(s). Published by the American Astronomical Society.Ítem VLT/MAGELLAN SPECTROSCOPY of 29 STRONG LENSING SELECTED GALAXY CLUSTERS(Institute of Physics Publishing, 2017-01) Carrasco, Mauricio; Barrientos, L. Felipe; Anguita, Timo; García-Vergara, Cristina; Bayliss, Matthew; Gladders, Michael; Gilbank, David; Yee H.K.C.; West, MichaelWe present an extensive spectroscopic follow-up campaign of 29 strong lensing (SL) selected galaxy clusters discovered primarily in the Second Red-Sequence Cluster Survey (RCS-2). Our spectroscopic analysis yields redshifts for 52 gravitational arcs present in the core of our galaxy clusters, which correspond to 35 distinct background sources that are clearly distorted by the gravitational potential of these clusters. These lensed galaxies span a wide redshift range of 0.8 ≤ z ≤ 2.9, with a median redshift of z s = 1.8 ± 0.1. We also measure reliable redshifts for 1004 cluster members, allowing us to obtain robust velocity dispersion measurements for 23 of these clusters, which we then use to determine their dynamical masses by using a simulation-based σ DM - M 200 scaling relation. The redshift and mass ranges covered by our SL sample are 0.22 ≤ z ≤ 1.01 and , respectively. We analyze and quantify some possible effects that might bias our mass estimates, such as the presence of substructure, the region where cluster members are selected for spectroscopic follow-up, the final number of confirmed members, and line-of-sight effects. We find that 10 clusters of our sample with N mem 20 show signs of dynamical substructure. However, the velocity data of only one system is inconsistent with a uni-modal distribution. We therefore assume that the substructures are only marginal and not of comparable size to the clusters themselves. Consequently, our velocity dispersion and mass estimates can be used as priors for SL mass reconstruction studies and also represent an important step toward a better understanding of the properties of the SL galaxy cluster population. © 2017. The American Astronomical Society. All rights reserved.