Repositorio Institucional Académico. Universidad Andrés Bello. Chile

Examinando por Autor "Anguita T."

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Gravitationally lensed quasars in Gaia – IV. 150 new lenses, quasar pairs, and projected quasars
(Oxford University Press, 2023-04-01) Lemon C.; Anguita T.; Auger-Williams M.W.; Courbin F.; Galan A.; McMahon R.; Neira F.; Oguri M.; Schechter P.; Shajib A.; Treu T.; Agnello A.; Spiniello C.
We report the spectroscopic follow-up of 175 lensed quasar candidates selected using Gaia Data Release 2 observations following Paper III of this series. Systems include 86 confirmed lensed quasars and a further 17 likely lensed quasars based on imaging and/or similar spectra. We also confirm 11 projected quasar pairs and 11 physical quasar pairs, while 25 systems are left as unclassified quasar pairs – pairs of quasars at the same redshift, which could be either distinct quasars or potential lensed quasars. Especially interesting objects include eight quadruply imaged quasars of which two have BAL sources, an apparent triple, and a doubly lensed LoBaL quasar. The source redshifts and image separations of these new lenses range between 0.65–3.59 and 0.78–6.23 arcsec, respectively. We compare the known population of lensed quasars to an updated mock catalogue at image separations between 1 and 4 arcsec, showing a very good match at z < 1.5. At z > 1.5, only 47 per cent of the predicted number are known, with 56 per cent of these missing lenses at image separations below 1.5 arcsec. The missing higher redshift, small-separation systems will have fainter lensing galaxies, and are partially explained by the unclassified quasar pairs and likely lenses presented in this work, which require deeper imaging. Of the 11 new reported projected quasar pairs, 5 have impact parameters below 10 kpc, almost tripling the number of such systems, which can probe the innermost regions of quasar host galaxies through absorption studies. We also report four new lensed galaxies discovered through our searches, with source redshifts ranging from 0.62 to 2.79. © 2023 Oxford University Press. All rights reserved.
MiNDSTEp differential photometry of the gravitationally lensed quasars WFI 2033-4723 and HE 0047-1756: Microlensing and a new time delay
(EDP Sciences, 2017) Giannini E.; Schmidt R.W.; Wambsganss J.; Alsubai K.; Andersen J.M.; Anguita T.; Bozza V.; Bramich D.M.; Browne P.; Calchi Novati S.; Damerdji Y.; Diehl C.; Dodds P.; Dominik M.; Elyiv A.; Fang X.; Figuera Jaimes R.; Finet F.; Gerner T.; Gu S.; Hardis S.; Harpsøe K.; Hinse T.C.; Hornstrup A.; Hundertmark M.; Jessen-Hansen J.; Jørgensen U.G.; Juncher D.; Kains N.; Kerins E.; Korhonen H.; Liebig C.; Lund M.N.; Lundkvist M.S.; Maier G.; Mancini L.; Masi G.; Mathiasen M.; Penny M.; Proft S.; Rabus M.; Rahvar S.; Ricci D.; Scarpetta G.; Sahu K.; Schäfer S.; Schönebeck F.; Skottfelt J.; Snodgrass C.; Southworth J.; Surdej J.; Tregloan-Reed J.; Vilela C.; Wertz O.; Zimmer F.
Aims. We present V and R photometry of the gravitationally lensed quasars WFI 2033-4723 and HE 0047-1756. The data were taken by the MiNDSTEp collaboration with the 1.54 m Danish telescope at the ESO La Silla observatory from 2008 to 2012. Methods. Differential photometry has been carried out using the image subtraction method as implemented in the HOTPAnTS package, additionally using GALFIT for quasar photometry. Results. The quasar WFI 2033-4723 showed brightness variations of order 0.5 mag in V and R during the campaign. The two lensed components of quasar HE 0047-1756 varied by 0.2-0.3 mag within five years. We provide, for the first time, an estimate of the time delay of component B with respect to A of Δt = (7.6 ± 1.8) days for this object. We also find evidence for a secular evolution of the magnitude difference between components A and B in both filters, which we explain as due to a long-duration microlensing event. Finally we find that both quasars WFI 2033-4723 and HE 0047-1756 become bluer when brighter, which is consistent with previous studies. © ESO, 2016.
STRIDES: Automated uniform models for 30 quadruply imaged quasars
(Oxford University Press, 2023-01) Schmidt T.; Treu T.; Birrer S.; Shajib A.J.; Lemon C.; Millon M.; Sluse D.; Agnello A.; Anguita T.; Auger-Williams M.W.; McMahon R.G.; Motta V.; Spiniello C.; Kayo I.; Courbin F.; Ertl S.; Fassnacht C.D.; Frieman J.A.; More A.; Schuldt S.; Suyu S.H.; Aguena M.; Andrade-Oliveira F.; Annis J.; Bacon D.; Bertin E.; Brooks D.; Burke D.L.; Carnero Rosell A.; Carrasco Kind M.; Carretero J.; Conselice C.; Costanzi M.; Da Costa L.N.; Pereira M.E.S.; De Vicente J.; Desai S.; Doel P.; Everett S.; Ferrero I.; Friedel D.; García-Bellido J.; Gaztanaga E.; Gruen D.; Gruendl R.A.; Gschwend J.; Gutierrez G.; Hinton S.R.; Hollowood D.L.; Honscheid K.; James D.J.; Kuehn K.; Lahav O.; Menanteau F.; Miquel R.; Palmese A.; Paz-Chinchón F.; Pieres A.; Plazas Malagón A.A.; Prat J.; Rodriguez-Monroy M.; Romer A.K.; Sanchez E.; Scarpine V.; Sevilla-Noarbe I.; Smith M.; Suchyta E.; Tarle G.; To C.; Varga T.N.
Gravitational time delays provide a powerful one-step measurement of H0, independent of all other probes. One key ingredient in time-delay cosmography are high-accuracy lens models. Those are currently expensive to obtain, both, in terms of computing and investigator time (105-106 CPU hours and ∼0.5-1 yr, respectively). Major improvements in modelling speed are therefore necessary to exploit the large number of lenses that are forecast to be discovered over the current decade. In order to bypass this roadblock, we develop an automated modelling pipeline and apply it to a sample of 31 lens systems, observed by the Hubble Space Telescope in multiple bands. Our automated pipeline can derive models for 30/31 lenses with few hours of human time and <100 CPU hours of computing time for a typical system. For each lens, we provide measurements of key parameters and predictions of magnification as well as time delays for the multiple images. We characterize the cosmography-readiness of our models using the stability of differences in the Fermat potential (proportional to time delay) with respect to modelling choices. We find that for 10/30 lenses, our models are cosmography or nearly cosmography grade (<3 per cent and 3-5 per cent variations). For 6/30 lenses, the models are close to cosmography grade (5-10 per cent). These results utilize informative priors and will need to be confirmed by further analysis. However, they are also likely to improve by extending the pipeline modelling sequence and options. In conclusion, we show that uniform cosmography grade modelling of large strong lens samples is within reach. © 2022 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society.
STRIDES: Spectroscopic and photometric characterization of the environment and effects of mass along the line of sight to the gravitational lenses des J0408-5354 and WGD 2038-4008
(Oxford University Press, 2020-11-01) Buckley-Geer E.J.; Lin H.; Rusu C.E.; Poh J.; Palmese A.; Agnello A.; Christensen L.; Frieman J.; Shajib A.J.; Treu T.; Collett T.; Birrer S.; Anguita T.; Fassnacht C.D.; Meylan G.; Mukherjee S.; Wong K.C.; Aguena M.; Allam S.; Avila S.; Bertin E.; Bhargava S.; Brooks D.; Carnero Rosell A.; Carrasco Kind M.; Carretero J.; Castander F.J.; Costanzi M.; Da Costa L.N.; De Vicente J.; Desai S.; Diehl H.T.; Doel P.; Eifler T.F.; Everett S.; Flaugher B.; Fosalba P.; Garciá-Bellido J.; Gaztanaga E.; Gruen D.; Gruendl R.A.; Gschwend J.; Gutierrez G.; Hinton S.R.; Honscheid K.; James D.J.; Kuehn K.; Kuropatkin N.; Maia M.A.G.; Marshall J.L.; Melchior P.; Menanteau F.; Miquel R.; Ogando R.L.C.; Paz-Chinchón F.; Plazas A.A.; Sanchez E.; Scarpine V.; Schubnell M.
In time-delay cosmography, three of the key ingredients are (1) determining the velocity dispersion of the lensing galaxy, (2) identifying galaxies and groups along the line of sight with sufficient proximity and mass to be included in the mass model, and (3) estimating the external convergence κext from less massive structures that are not included in the mass model. We present results on all three of these ingredients for two time-delay lensed quad quasar systems, DES J0408-5354 and WGD 2038-4008. We use the Gemini, Magellan, and VLT telescopes to obtain spectra to both measure the stellar velocity dispersions of the main lensing galaxies and to identify the line-of-sight galaxies in these systems. Next, we identify 10 groups in DES J0408-5354 and two groups in WGD 2038-4008 using a group-finding algorithm. We then identify the most significant galaxy and galaxy-group perturbers using the 'flexion shift' criterion. We determine the probability distribution function of the external convergence κext for both of these systems based on our spectroscopy and on the DES-only multiband wide-field observations. Using weighted galaxy counts, calibrated based on the Millennium Simulation, we find that DES J0408-5354 is located in a significantly underdense environment, leading to a tight (width ∼ 3%), negative-value κext distribution. On the other hand, WGD 2038-4008 is located in an environment of close to unit density, and its low source redshift results in a much tighter κext of ~1%, as long as no external shear constraints are imposed.
The ALMA Frontier Fields Survey: I. 1.1 mm continuum detections in Abell 2744, MACS J0416.1-2403 and MACS J1149.5+2223
(EDP Sciences, 2017) González-López J.; Bauer F.E.; Romero-Cañizales C.; Kneissl R.; Villard E.; Carvajal R.; Kim S.; Laporte N.; Anguita T.; Aravena M.; Bouwens R.J.; Bradley L.; Carrasco M.; Demarco R.; Ford H.; Ibar E.; Infante L.; Messias H.; Muñoz Arancibia A.M.; Nagar N.; Padilla N.; Treister E.; Troncoso P.; Zitrin A.
Context. Dusty star-forming galaxies are among the most prodigious systems at high redshift (z> 1), characterized by high starformation rates and huge dust reservoirs. The bright end of this population has been well characterized in recent years, but considerable uncertainties remain for fainter dusty star-forming galaxies, which are responsible for the bulk of star formation at high redshift and thus play a key role in galaxy growth and evolution. Aims. In this first paper of our series, we describe our methods for finding high redshift faint dusty galaxies using millimeter observations with ALMA. Methods. We obtained ALMA 1.1mm mosaic images for three strong-lensing galaxy clusters from the Frontier Fields Survey, which constitute some of the best studied gravitational lenses to date. The 20 20 mosaics overlap with the deep HST WFC3/IR footprints and encompass the high magnification regions of each cluster for maximum intrinsic source sensitivity. The combination of extremely high ALMA sensitivity and the magnification power of these clusters allows us to systematically probe the sub-mJy population of dusty star-forming galaxies over a large surveyed area. Results. We present a description of the reduction and analysis of the ALMA continuum observations for the galaxy clusters Abell 2744 (z = 0:308), MACS J0416.1-2403 (z = 0:396) and MACS J1149.5+2223 (z = 0:543), for which we reach observed rms sensitivities of 55, 59 and 71 Jy beam-1 respectively.We detect 12 dusty star-forming galaxies at S=N 5:0 across the three clusters, all of them presenting coincidence with near-infrared detected counterparts in the HST images. None of the sources fall close to the lensing caustics, thus they are not strongly lensed. The observed 1.1mm flux densities for the total sample of galaxies range from 0.41 to 2.82 mJy, with observed effective radii spanning .00:005 to 00:037 00:021. The lensing-corrected sizes of the detected sources appear to be in the same range as those measured in brighter samples, albeit with possibly larger dispersion. © ESO 2016.
The ALMA frontier fields survey: IV. Lensing-corrected 1.1 mm number counts in Abell 2744, MACS J0416.1-2403 and MACS J1149.5+2223
(EDP Sciences, 2018-12) Muñoz Arancibia A.M.; González-López J.; Bauer F.E.; Carrasco M.; Laporte N.; Anguita T.; Aravena M.; Barrientos F.; Bouwens R.J.; Demarco R.; Infante L.; Kneissl R.l.; Nagar N.; Padilla N.; Romero-Cañizales C.; Troncoso P.; trin A.; Ibar E.
Context. Characterizing the number counts of faint (i.e., sub-mJy and especially sub-100 μJy), dusty star-forming galaxies is currently a challenge even for deep, high-resolution observations in the FIR-to-mm regime. They are predicted to account for approximately half of the total extragalactic background light at those wavelengths. Searching for dusty star-forming galaxies behind massive galaxy clusters benefits from strong lensing, enhancing their measured emission while increasing spatial resolution. Derived number counts depend, however, on mass reconstruction models that properly constrain these clusters. Aims. We aim to estimate the 1.1 mm number counts along the line of sight of three galaxy clusters, Abell 2744, MACS J0416.1-2403, and MACS J1149.5+2223, which are part of the ALMA Frontier Fields Survey. We have performed detailed simulations to correct these counts for lensing effects, probing down to the sub-mJy flux density level. Methods. We created a source catalog based on ALMA 1.1 mm continuum detections. We used several publicly available lensing models for the galaxy clusters to derive the intrinsic flux densities of these sources. We performed Monte Carlo simulations of the number counts for a detailed treatment of the uncertainties in the magnifications and adopted source redshifts. Results. We estimate lensing-corrected number counts at 1.1 mm using source detections down to S/N = 4.5. In each cluster field, we find an overall agreement among the number counts derived for the different lens models, despite their systematic variations regarding source magnifications and effective areas. Combining all cluster fields, our number counts span ∼2.5 dex in demagnified flux density, from several mJy down to tens of μJy. Both our differential and cumulative number counts are consistent with recent estimates from deep ALMA observations at a 3σ level. Below ≈ 0.1 mJy, however, our cumulative counts are lower by ≈ 1 dex, suggesting a flattening in the number counts. Conclusions. We derive 1.1 mm number counts around three well-studied galaxy clusters following a statistical approach. In our deepest ALMA mosaic, we estimate number counts for intrinsic flux densities ≈ 4 times fainter than the rms level. This highlights the potential of probing the sub-10 μJy population in larger samples of galaxy cluster fields with deeper ALMA observations. © ESO 2018.
The ALMA Frontier Fields Survey: VI. Lensing-corrected 1.1 mm number counts in Abell 2744, MACSJ0416.1-2403, MACSJ1149.5+2223, Abell 370, and Abell S1063
(EDP Sciences, 2023) Muñoz Arancibia A.M.; González-López J.; Ibar E.; Bauer F.E; Anguita T.; Aravena M.; Demarco R.; Kneissl R.; Koekemoer A.M.; Troncoso-Iribarren P.; Zitrin A.
Context. Probing the faint end of the number counts at millimeter wavelengths is important in order to identify the origin of the extragalactic background light in this regime. Aided by strong gravitational lensing, ALMA observations toward massive galaxy clusters have opened a window to probe this origin, allowing us to resolve sub-milliJansky dusty star-forming galaxies. Aims. We aim to derive number counts at 1.1 mm down to flux densities fainter than 0.1 mJy based on ALMA observations toward five Hubble Frontier Fields (FF) galaxy clusters, following a statistical approach to correct for lensing effects. Methods. We created a source catalog that includes ALMA 1.1 mm continuum detections around two new FF galaxy clusters, together with the sources previously detected around three FF galaxy clusters, making a total of 29 detected sources down to a 4.5σ significance. ALMA 1.1 mm mosaics used for our source extraction covered the inner ≈2′ × 2′; FF regions, reached rms depths of ≈55 - 71μJy beam-1, and had synthesized beam sizes from ≈0″.5 - 1″.5 (natural weighting). We derived source intrinsic flux densities using public lensing models. We folded the uncertainties in both magnifications and source redshifts into the number counts through Monte Carlo simulations. Results. Using the combination of all cluster fields, we derive cumulative number counts over two orders of magnitude down to ≈0.01 mJy after correction for lensing effects. Cosmic variance estimates are all exceeded by uncertainties in our median combined cumulative counts that come from both our Monte Carlo simulations and Poisson statistics. Our number counts agree at a 1σ level with our previous estimates using ALMA observations of the first three FFs, exhibiting a similar flattening at faint flux densities. They are also consistent to 1σ with most recent ALMA estimates and galaxy evolution models. However, below ≈0.1 mJy, our cumulative number counts are lower by ≈0.4 dex compared to two deep ALMA studies (namely one that probes several blank fields plus one lensed galaxy cluster, and the initial ALMA Spectroscopic Survey in the Hubble Ultra Deep Field, ASPECS-Pilot), while remaining consistent with the ASPECS Large Program (ASPECS-LP) within 1σ. Importantly, the flattening found for our cumulative counts at ≲0.1 mJy also extends further to ≈0.01 mJy, that is, ≈0.4 dex fainter than ASPECS-LP, and remains in agreement with extrapolations of their number counts down to this flux limit. We find a median contribution to the extragalactic background light (EBL) of 14-8+12 Jy deg-2 resolved in our demagnified sources down to ≈0.01 mJy, representing 75 - 86% of Planck-derived extragalactic EBL estimates at 1.1 mm. Conclusions. We estimate cumulative 1.1 mm number counts down to ≈0.01 mJy along the line of sight of five galaxy clusters that benefit from having rich deep multiwavelength data. They bring further support to the flattening of the number counts reported previously by us and ASPECS-LP, which has been interpreted by a recent galaxy evolution model as a measurement of the "knee"of the infrared luminosity function at high redshift. Our estimates of the contribution to the EBL associated with 1.1 mm galaxies in the FFs suggest that we may be resolving most of the EBL at this wavelength down to ≈0.01 mJy. © M. Grandin et al., Published by EDP Sciences 2023M. Grandin et al., Published by EDP Sciences 2023
The STRong lensing Insights into the Dark Energy Survey (STRIDES) 2016 follow-up campaign - II. New quasar lenses from double component fitting
(Oxford University Press, 2018-11) Anguita T.; Schechter P.L.; Kuropatkin N.; Morgan N.D.; Ostrovski F.; Abramson L.E.; Agnello A.; Apostolovski Y.; Fassnacht C.D.; Hsueh J.W.; Motta V.; Rojas K.; Rusu C.E.; Treu T.; Williams P.; Auger M.; Buckley-Geer E.; Lin H.; McMahon R.; Abbott T.M.C.; Allam S.; Annis J.; Bernstein R.A.; Bertin E.; Brooks D.; Burke D.L.; Carnero Rosell A.; Carrasco-Kind M.; Carretero J.; Cunha C.E.; D'Andrea C.B.; De Vicente J.; Depoy D.L.; Desai S.; DIehl H.T.; Doel P.; Flaugher B.; García-Bellido J.; Gerdes D.W.; Gschwend J.; Hartley W.G.; Hollowood D.L.; Honscheid K.; James D.J.; Kuehn K.; Lima M.; Maia M.A.G.; Miquel R.; Plazas A.A.; Sanchez E.; Scarpine V.; Smith M.; Soares-Santos M.; Sobreira F.; Suchyta E.; Tarle G.; Walker A.R.; Gruent, D.
We report upon the follow-up of 34 candidate lensed quasars found in the Dark Energy Survey using NTT EFOSC, Magellan-IMACS, KECK-ESI, and SOAR-SAMI. These candidates were selected by a combination of double component fitting, morphological assessment, and colour analysis. Most systems followed up are indeed composed of at least one quasar image and 13 with two or more quasar images: two lenses, four projected binaries, and seven nearly identical quasar pairs (NIQs). The two systems confirmed as genuine gravitationally lensed quasars are one quadruple at $z$s = 1.713 and one double at $z$s = 1.515. Lens modelling of these two systems reveals that both systems require very little contribution from the environment to reproduce the image configuration. Nevertheless, small flux anomalies can be observed in one of the images of the quad. Further observations of nine inconclusive systems (including seven NIQs) will allow to confirm (or not) their gravitational lens nature. © 2018 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society.

Examinando por Autor "Anguita T."

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