Browsing by Author "Hounsell, R"

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    A Reference Survey for Supernova Cosmology with the Nancy Grace Roman Space Telescope
    Rose, BM; Baltay, C; Hounsell, R; Macias, P; Rubin, D; Scolnic, D; Aldering, G; Bohlin, R; Dai, M; Deustua, SE; Foley, RJ; Fruchter, A; Galbany, L; Jha, SW; Jones, DO; Joshi, BA; Kelly, PL; Kessler, R; Kirshner, RP; Mandel, KS; Perlmutter, S; Pierel, J; Qu, H; Rabinowitz, D; Rest, A; Riess, AG; Rodney, S; Sako, M; Siebert, MR; Strolger, L; Suzuki, N; Thorp, S; Dyk, SD Van; Wang, K; Ward, SM; Wood-Vasey, WM
    This note presents an initial survey design for the Nancy Grace Roman High-latitude Time Domain Survey. This is not meant to be a final or exhaustive list of all the survey strategy choices, but instead presents a viable path towards achieving the desired precision and accuracy of dark energy measurements using Type Ia supernovae (SNe Ia). We describe a survey strategy that use six filters (RZYJH and F) and the prism on the Roman Wide Field Instrument. This survey has two tiers, one "wide" which targets SNe Ia at redshifts up to 1 and one "deep" targeting redshifts up to 1.7; for each, four filters are used (with Y and J used in both tiers). We propose one field each in the north and south continuous viewing zones, and expect to obtain high-quality distances of $\sim$12,000 SNe Ia with $\sim$5,000 at z > 1. We propose a wide-tier area of $\sim$19 deg$^2$ and a deep tier of $\sim$5 deg$^2$. Exposure times range from 100 s to 900 s for imaging and 900 s to 3600 s for the prism. These exposure times would reach $\sim$25.5 mag and $\sim$26.5 mag for the wide and deep tiers respectively, with deep co-add stacks reaching $\sim$28 mag and $\sim$29 mag. The total survey spans two years, with a total allocation time of six months, and a cadence of $\sim$5 days.
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    Supernova Siblings: Assessing the Consistency of Properties of Type Ia Supernovae that Share the Same Parent Galaxies
    Scolnic, D; Smith, M; Massiah, A; Wiseman, P; Brout, D; Kessler, R; Davis, TM; Foley, RJ; Galbany, L; Hinton, SR; Hounsell, R; Kelsey, L; Lidman, C; Macaulay, E; Morgan, R; Nichol, RC; Möller, A; Popovic, B; Sako, M; Sullivan, M; Thomas, BP; Tucker, BE; Abbott, TMC; Aguena, M; Allam, S; Annis, J; Avila, S; Bechtol, K; Bertin, E; Brooks, D; Burke, DL; Rosell, AC; Carollo, D; Kind, MC; Carretero, J; Costanzi, M; Da Costa, LN; De Vicente, J; Desai, S; Diehl, HT; Doel, P; Drlica-Wagner, A; Eckert, K; Eifler, TF; Everett, S; Flaugher, B; Fosalba, P; Frieman, J; Garciá-Bellido, J; Gaztanaga, E; Gerdes, DW; Glazebrook, K; Gruen, D; Gruendl, RA; Gschwend, J; Gutierrez, G; Hartley, WG; Hollowood, DL; Honscheid, K; James, DJ; Kuehn, K; Kuropatkin, N; Lewis, GF; Li, TS; Lima, M; Maia, MAG; Marshall, JL; Menanteau, F; Miquel, R; Palmese, A; Paz-Chinchón, F; Plazas, AA; Pursiainen, M; Sanchez, E; Scarpine, V; Schubnell, M; Serrano, S; Sevilla-Noarbe, I; Sommer, NE; Suchyta, E; Swanson, MEC; Tarle, G; Varga, TN; Walker, AR; Wilkinson, R
    While many studies have shown a correlation between properties of the light curves of Type Ia SN (SNe Ia) and properties of their host galaxies, it remains unclear what is driving these correlations. We introduce a new direct method to study these correlations by analyzing `parent' galaxies that host multiple SNe Ia 'siblings'. Here, we search the Dark Energy Survey SN sample, one of the largest samples of discovered SNe, and find 8 galaxies that hosted two likely Type Ia SNe. Comparing the light-curve properties of these SNe and recovered distances from the light curves, we find no better agreement between properties of SNe in the same galaxy as any random pair of galaxies, with the exception of the SN light-curve stretch. We show at $2.8\sigma$ significance that at least 1/2 of the intrinsic scatter of SNe Ia distance modulus residuals is not from common host properties. We also discuss the robustness with which we could make this evaluation with LSST, which will find $100\times$ more pairs of galaxies, and pave a new line of study on the consistency of Type Ia supernovae in the same parent galaxies. Finally, we argue that it is unlikely some of these SNe are actually single, lensed SN with multiple images.
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    Synergies between Vera C. Rubin Observatory, Nancy Grace Roman Space Telescope, and Euclid Mission: Constraining Dark Energy with Type Ia Supernovae
    Rose, BM; Aldering, G; Dai, M; Deustua, S; Foley, RJ; Gangler, E; Gris, Ph; Hook, IM; Kessler, R; Narayan, G; Nugent, P; Ponder, S Perlmutte KA; Racine, B; Rubin, D; Sánchez, BO; Scolnic, DM; Wood-Vasey, WM; Brout, D; Cikota, A; Fouchez, D; Garnavich, PM; Hounsell, R; Sako, M; Tao, C; Jha, SW; Jones, DO; Strolger, L; Qu, H
    We review the needs of the supernova community for improvements in survey coordination and data sharing that would significantly boost the constraints on dark energy using samples of Type Ia supernovae from the Vera C. Rubin Observatories, the \textit{Nancy Grace Roman Space Telescope}, and the \textit{Euclid} Mission. We discuss improvements to both statistical and systematic precision that the combination of observations from these experiments will enable. For example, coordination will result in improved photometric calibration, redshift measurements, as well as supernova distances. We also discuss what teams and plans should be put in place now to start preparing for these combined data sets. Specifically, we request coordinated efforts in field selection and survey operations, photometric calibration, spectroscopic follow-up, pixel-level processing, and computing. These efforts will benefit not only experiments with Type Ia supernovae, but all time-domain studies, and cosmology with multi-messenger astrophysics.
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    The Dark Energy Survey Supernova Program: Modelling selection efficiency and observed core collapse supernova contamination
    Vincenzi, M; Sullivan, M; Graur, O; Brout, D; Davis, TM; Frohmaier, C; Galbany, L; Gutiérrez, CP; Hinton, SR; Hounsell, R; Kelsey, L; Kessler, R; Kovacs, E; Kuhlmann, S; Lasker, J; Lidman, C; Möller, A; Nichol, RC; Sako, M; Scolnic, D; Smith, M; Swann, E; Wiseman, P; Asorey, J; Lewis, GF; Sharp, R; Tucker, BE; Aguena, M; Allam, S; Avila, S; Bertin, E; Brooks, D; Burke, DL; Rosell, AC; Kind, MC; Carretero, J; Castander, FJ; Choi, A; Costanzi, M; Da Costa, LN; Pereira, MES; De Vicente, J; Desai, S; Diehl, HT; Doel, P; Everett, S; Ferrero, I; Fosalba, P; Frieman, J; Garciá-Bellido, J; Gaztanaga, E; Gerdes, DW; Gruen, D; Gruendl, RA; Gutierrez, G; Hollowood, DL; Honscheid, K; Hoyle, B; James, DJ; Kuehn, K; Kuropatkin, N; Maia, MAG; Martini, P; Menanteau, F; Miquel, R; Morgan, R; Palmese, A; Paz-Chinchón, F; Plazas, AA; Romer, AK; Sanchez, E; Scarpine, V; Serrano, S; Sevilla-Noarbe, I; Soares-Santos, M; Suchyta, E; Tarle, G; Thomas, D; To, C; Varga, TN; Walker, AR; Wilkinson, RD
    The analysis of current and future cosmological surveys of type Ia supernovae (SNe Ia) at high-redshift depends on the accurate photometric classification of the SN events detected. Generating realistic simulations of photometric SN surveys constitutes an essential step for training and testing photometric classification algorithms, and for correcting biases introduced by selection effects and contamination arising from core collapse SNe in the photometric SN Ia samples. We use published SN time-series spectrophotometric templates, rates, luminosity functions and empirical relationships between SNe and their host galaxies to construct a framework for simulating photometric SN surveys. We present this framework in the context of the Dark Energy Survey (DES) 5-year photometric SN sample, comparing our simulations of DES with the observed DES transient populations. We demonstrate excellent agreement in many distributions, including Hubble residuals, between our simulations and data. We estimate the core collapse fraction expected in the DES SN sample after selection requirements are applied and before photometric classification. After testing different modelling choices and astrophysical assumptions underlying our simulation, we find that the predicted contamination varies from 5.8 to 9.3 per cent, with an average of 7.0 per cent and r.m.s. of 1.1 per cent. Our simulations are the first to reproduce the observed photometric SN and host galaxy properties in high-redshift surveys without fine-tuning the input parameters. The simulation methods presented here will be a critical component of the cosmology analysis of the DES photometric SN Ia sample: correcting for biases arising from contamination, and evaluating the associated systematic uncertainty.