Cosmological radiative transfer codes comparison project – I. The static density field tests

By Ilian Iliev, Benedetta Ciardi, M. Alvarez, Antonella Maselli, A. Ferrara, Nickolay Y. Gnedin, G. Mellema, T. Nakamoto, M. Norman, A. Razoumov and 17 more. 2006

188 citations recorded by the source corpus.

Radiative transfer (RT) simulations are now at the forefront of numerical astrophysics. They are becoming crucial for an increasing number of astrophysical and cosmological problems; at the same time their computational cost has come within reach of currently available computational power. Further progress is retarded by the considerable number of different algorithms (including various flavours of ray tracing and moment schemes) developed, which makes the selection of the most suitable technique for a given problem a non-trivial task. Assessing the validity ranges, accuracy and performances of these schemes is the main aim of this paper, for which we have compared 11 independent RT codes on five test problems: (0) basic physics; (1) isothermal H II region expansion; (2) H II region expansion with evolving temperature; (3) I-front trapping and shadowing by a dense clump and (4) multiple sources in a cosmological density field. The outputs of these tests have been compared and differences analysed. The agreement between the various codes is satisfactory although not perfect. The main source of discrepancy appears to reside in the multifrequency treatment approach, resulting in different thicknesses of the ionized-neutral transition regions and the temperature structure. The present results and tests represent the most complete benchmark available for the development of new codes and improvement of existing ones. To further this aim all test inputs and outputs are made publicly available in digital form.

Subfields: Astronomy and Astrophysics

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Citations in the corpus

Mapping Neutral Hydrogen during Reionization with the Lyα Emission from Quasar Ionization Fronts (2007, unknown): “This is difficult to follow with most RT codes (see Iliev et al. 2006 for a recent compilation), including our own, in which the ray-tracing algorithm assumes an infinite light speed and ionization fronts tend to propagate faster than light at early times.”
A comparison of chemistry and dust cloud formation in ultracool dwarf model atmospheres (2008, background): “Comparative studies have been carried out for simulations of radiative transfer (Pascucci et al. 2004; Iliev et al. 2006), white dwarfs (Barstow et al. 2001) or photon-dominated region (Röllig et al. 2007).”
Three-Dimensional Dust Radiative Transfer ∗ (2013, background): “…Zadelhoff et al. 2002), halo and void finder algorithms (Colberg et al. 2008, Knebe et al. 2011), astrophysical hydrodynamics (Agertz et al. 2007), cosmological hydrodynamical simulations (Frenk et al. 1999, O’Shea et al. 2005), and cosmological radiation hydrodynamics (Iliev et al. 2006, 2009).”
Extended Lyman-alpha emission from cold accretion streams (2011, methodology): “We have tested and verified RamsesRT with the benchmark tests of the ‘Cosmological radiative transfer comparison project’ (Iliev et al. 2006, 2009), and the results will be presented in Rosdahl et al. (2012, in prep.).”
ramses-rt: radiation hydrodynamics in the cosmological context (2013, methodology): “Comparative evaluations of both methods have been performed in several papers (Iliev et al. 2006b, 2009; Altay, Croft & Pelupessy 2008; Aubert & Teyssier 2008; Pawlik & Schaye 2008, 2011; Maselli, Ciardi & Kanekar 2009; at U niversitaet Z uerich on February 11, 2014…”
Damped Lyman α systems in galaxy formation simulations (2008, unknown): “Our self-shielding process is crude when compared to recent radiative transfer codes (for a comparison see Iliev et al. 2006); however, we do not believe this makes our results obsolete: se Section 5.4.”
Reionization and Cosmology with 21-cm Fluctuations (2009, background): “On the other hand numerical simulations do not yet agree among themselves at a comparable level (Iliev et al. 2006).”
Comparison of reionization models: radiative transfer simulations and approximate, seminumeric models (2010, background): “A few groups have recently come close to achieving this dynamic range (Iliev et al. 2006a; McQuinn et al. 2007b; Trac & Cen 2007; Shin et al. 2008; Trac et al. 2008; see the recent review in Trac & Gnedin 2009).10 In addition, promising analytic alternatives have been suggested (e.g. Furlanetto et…”
Simulating cosmic reionization at large scales – II. The 21-cm emission features and statistical signals (2006, methodology): “The code has been tested in detail against available ana ytical solutions (Mellema et al. 2006) and in comparison with ot er radiative transfer codes (Iliev et al. 2006).”
H II REGIONS: WITNESSES TO MASSIVE STAR FORMATION (2010, background): “The radiation module has been tested for its capability of accurately casting shadows (Rijkhorst et al. 2006) and tracing R-type ionization fronts in a cosmological setting (Iliev et al. 2006).”
Fluctuating feedback-regulated escape fraction of ionizing radiation in low-mass, high-redshift galaxies (2017, methodology): “…& Cen 2007; Dayal et al. 2008; Mitra et al. 2015; Mutch et al. 2016) or are based on large scale simulations (e.g. Gnedin 2014; Ricotti et al. 2002; Iliev et al. 2006, 2014; Ocvirk et al. 2016), and all of them use fesc directly or indirectly, the fraction of ionizing photons that escape the…”
Escape of Ionizing Radiation from High-Redshift Galaxies (2007, methodology): “A comparison of our radiative transfer scheme with several other existing numerical implementations for the time-dependent and spatially-inhomogeneous radiative transfer is presented in Iliev et al. (2006) and inthe follow-up paper (Iliev et al. 2007, in preparation).”
Efficient Simulations of Early Structure Formation and Reionization (2007, background): “We note, however, that the situation at high redshifts is less clear: studies disagree on the relative accuracy of the Press & Schechter (1974) and Jenkins et al. (2001) forms (Reed et al. 2003; Iliev et al. 2006b; Zahn et al. 2007).”
21CMMC: an MCMC analysis tool enabling astrophysical parameter studies of the cosmic 21 cm signal (2015, methodology): “In addition to the thermal noise and sample variance, we add an additional uncertainty due to EoR modelling, accounting for, e.g. differences in the implementation of RT (e.g. Iliev et al. 2006) and errors in semi-numerical approximations (e.g. Zahn et al. 2011).”
Physical Models of Galaxy Formation in a Cosmological Framework (2014, methodology): “Two approaches are used: applying radiative transfer in post-processing to existing density distributions (Iliev et al. 2006), which is useful for evolving large volumes to study the final stages of EoR; and full radiative hydrodynamic codes that evolve the ionizing field together with the baryons,…”
Self-regulated reionization (2006, methodology): “…conditions in the radiative transfer 2 The integrated electron-scattering optical depths for ourlarge-box simulations were estimated incorrectly in Iliev et al. (2006b) and Mellema et al. (2006b), the correct, slightly lower, values are listed in Table 1 c© 2006 RAS, MNRAS000, 1 simulations are…”
Escape fraction of ionizing photons from high-redshift galaxies in cosmological SPH simulations (2010, methodology): “The performance of our RT code has already been reported as part of the RT code comparison study by Iliev et al. (2006), and it can calculate the ionization structure precisely (see Figure 6 in Iliev et al. 2006).”
Inside-out or outside-in: the topology of reionization in the photon-starved regime suggested by Lyα forest data (2008, methodology): “…2 http://web.phys.cmu.edu/ past/ 3 http://www.haystack.mit.edu/ast/arrays/mwa/ 4 http://www.lofar.org/ 5 http://www.skatelescope.org/ 2000; Ciardi, Ferrara, & White 2003; Paschos & Norman 2005; Iliev et al. 2006b; Iliev et al. 2006a; Iliev et al. 2007; McQuinn et al. 2007).”