Examinando por Autor "Palmese A."
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Ítem Constraints on the Physical Properties of GW190814 through Simulations Based on DECam Follow-up Observations by the Dark Energy Survey(IOP Publishing Ltd, 2020-09) Morgan R.; Soares-Santos M.; Annis J.; Herner K.; Garcia A.; Palmese A.; Drlica-Wagner A.; Kessler R.; Garciá-Bellido J.; Bachmann T.G.; Sherman N.; Allam S.On 2019 August 14, the LIGO and Virgo Collaborations detected gravitational waves from a black hole and a 2.6 solar mass compact object, possibly the first neutron star-black hole merger. In search of an optical counterpart, the Dark Energy Survey (DES) obtained deep imaging of the entire 90% confidence level localization area with Blanco/DECam 0, 1, 2, 3, 6, and 16 nights after the merger. Objects with varying brightness were detected by the DES Pipeline, and we systematically reduced the candidate counterparts through catalog matching, light-curve properties, host-galaxy photometric redshifts, Southern Astrophysical Research spectroscopic follow-up observations, and machine-learning-based photometric classification. All candidates were rejected as counterparts to the merger. To quantify the sensitivity of our search, we applied our selection criteria to full light-curve simulations of supernovae and kilonovae as they would appear in the DECam observations. Because the source class of the merger was uncertain, we utilized an agnostic, three-component kilonova model based on tidally disrupted neutron star (NS) ejecta properties to quantify our detection efficiency of a counterpart if the merger included an NS. We find that, if a kilonova occurred during this merger, configurations where the ejected matter is greater than 0.07 solar masses, has lanthanide abundance less than 10-8.56, and has a velocity between 0.18c and 0.21c are disfavored at the 2σ level. Furthermore, we estimate that our background reduction methods are capable of associating gravitational wave signals with a detected electromagnetic counterpart at the 4σ level in 95% of future follow-up observations. © 2020 The American Astronomical Society. All rights reserved.Ítem Designing an Optimal Kilonova Search Using DECam for Gravitational-wave Events(Institute of Physics, 2024-02) Bom C.R.; Annis J.; Garcia A.; Palmese A.; Sherman N.; Soares-Santos M.; Santana-Silva L.; Morgan R.; Bechtol K.; Davis T.; Diehl H.T.; Allam S.S.; Bachmann T.G.; Fraga B.M.O.; García-Bellido J.; Gill M.S.S.; Herner K.; Kilpatrick C.D.; Makler M.; Olivares E. F.; Pereira M.E.S.; Pineda J.; Santos A.; Tucker D.L.; Wiesner M.P.; Aguena M.; Alves O.; Bacon D.; Bernardinelli P.H.; Bertin E.; Bocquet S.; Brooks D.; Carrasco Kind M.; Carretero J.; Conselice C.; Costanzi M.; da Costa L.N.; De Vicente J.; Desai S.; Doel P.; Everett S.; Ferrero I.; Frieman J.; Gatti M.; Gerdes D.W.; Gruen D.; Gruendl R.A.; Gutierrez G.; Hinton S.R.; Hollowood D.L.; Honscheid K.; James D.J.; Kuehn K.; Kuropatkin N.; Melchior P.; Mena-Fernández J.; Menanteau F.; Pieres A.; Plazas Malagón A.A.; Raveri M.; Rodriguez-Monroy M.; Sanchez E.; Santiago B.; Sevilla-Noarbe I.; Smith M.; Suchyta E.; Swanson M.E.C.; Tarle G.; To C.; Weaverdyck N.We address the problem of optimally identifying all kilonovae detected via gravitational-wave emission in the upcoming LIGO/Virgo/KAGRA observing run, O4, which is expected to be sensitive to a factor of ∼7 more binary neutron star (BNS) alerts than previously. Electromagnetic follow-up of all but the brightest of these new events will require >1 m telescopes, for which limited time is available. We present an optimized observing strategy for the DECam during O4. We base our study on simulations of gravitational-wave events expected for O4 and wide-prior kilonova simulations. We derive the detectabilities of events for realistic observing conditions. We optimize our strategy for confirming a kilonova while minimizing telescope time. For a wide range of kilonova parameters, corresponding to a fainter kilonova compared to GW170817/AT 2017gfo, we find that, with this optimal strategy, the discovery probability for electromagnetic counterparts with the DECam is ∼80% at the nominal BNS gravitational-wave detection limit for O4 (190 Mpc), which corresponds to an ∼30% improvement compared to the strategy adopted during the previous observing run. For more distant events (∼330 Mpc), we reach an ∼60% probability of detection, a factor of ∼2 increase. For a brighter kilonova model dominated by the blue component that reproduces the observations of GW170817/AT 2017gfo, we find that we can reach ∼90% probability of detection out to 330 Mpc, representing an increase of ∼20%, while also reducing the total telescope time required to follow up events by ∼20%. © 2024. The Author(s). Published by the American Astronomical Society.Ítem 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.Ítem 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.