DOCSLIB.ORG

The Illustristng Simulations: Public Data Release

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Illustristng Simulations: Public Data Release Dylan Nelson et al. RESEARCH The IllustrisTNG Simulations: Public Data Releasey Dylan Nelson1*, Volker Springel1,6,7, Annalisa Pillepich2, Vicente Rodriguez-Gomez8, Paul Torrey9,5, Shy Genel4, Mark Vogelsberger5, Ruediger Pakmor1,6, Federico Marinacci10,5, Rainer Weinberger3, Luke Kelley11, Mark Lovell12,13, Benedikt Diemer3 and Lars Hernquist3 y Permanently available at www.tng-project.org/data Main Text 1 Introduction Some of our most powerful tools for understanding the origin and evolution of large-scale cosmic structure and Abstract the galaxies which form therein are cosmological simu- We present the full public release of all data lations. From pioneering beginnings (Davis et al., 1985; from the TNG50, TNG100 and TNG300 simu- Press and Schechter, 1974), dark matter, gravity-only lations of the IllustrisTNG project. IllustrisTNG simulations have evolved into cosmological hydrody- is a suite of large volume, cosmological, gravo- namical simulations (Katz et al., 1992). These aim to magnetohydrodynamical simulations run with the self-consistently model the coupled evolution of dark moving-mesh code Arepo. TNG includes a com- matter, gas, stars, and blackholes at a minimum, and prehensive model for galaxy formation physics, and are now being extended to also include magnetic fields, each TNG simulation self-consistently solves for the radiation, cosmic rays, and other fundamental physi- coupled evolution of dark matter, cosmic gas, lumi- cal components. Such simulations provide foundational nous stars, and supermassive blackholes from early support in our understanding of the ΛCDM cosmolog- time to the present day, z = 0. Each of the flagship ical model, including the nature of both dark matter runs { TNG50, TNG100, and TNG300 { are ac- and dark energy. companied by halo/subhalo catalogs, merger trees, Modern large-volume simulations now capture cos- lower-resolution and dark-matter only counterparts, mological scales of tens to hundreds of comoving mega- all available with 100 snapshots. We discuss scien- parsecs, while simultaneously resolving the internal tific and numerical cautions and caveats relevant structure of individual galaxies at . 1 kpc scales. Re- when using TNG. cent examples reaching z = 0 include Illustris (Genel The data volume now directly accessible online et al., 2014; Vogelsberger et al., 2014b), EAGLE (Crain is ∼1.1 PB, including 2,000 full volume snapshots et al., 2015; Schaye et al., 2015), Horizon-AGN (Dubois and ∼115,000 high time-resolution subbox snap- et al., 2014), Romulus (Tremmel et al., 2017), Simba shots. Data access and analysis examples are avail- (Dav´eet al., 2019), Magneticum (Dolag et al., 2016), able in IDL, Python, and Matlab. We describe im- among others. These simulations produce observation- provements and new functionality in the web-based ally verifiable outcomes across a diverse range of astro- API, including on-demand visualization and analysis physical regimes, from the stellar and gaseous proper- arXiv:1812.05609v3 [astro-ph.GA] 29 Jan 2021 of galaxies and halos, exploratory plotting of scal- ties of galaxies, galaxy populations, and the supermas- ing relations and other relationships between galac- sive blackholes they host, to the expected distribution tic and halo properties, and a new JupyterLab inter- of molecular, neutral, and ionized gas tracers across face. This provides an online, browser-based, near- interstellar, circumgalactic, and intergalactic scales, in native data analysis platform enabling user compu- addition to the expected distribution of the dark mat- tation with local access to TNG data, alleviating the ter component itself. need to download large datasets. Complementary efforts, although not the focus of this data release, include high redshift reionization- Keywords: methods: data analysis; methods: era simulations such as BlueTides (Feng et al., 2016), numerical; galaxies: formation; galaxies: evolution; data management systems; data access methods, *Correspondence: [email protected] 1Max-Planck-Institut f¨urAstrophysik, Karl-Schwarzschild Str. 1, 85741 distributed architectures Garching, Germany Full list of author information is available at the end of the article Dylan Nelson et al. Page 2 of 30 Sphinx (Rosdahl et al., 2018), and CoDa II (Ocvirk Other dark-matter only simulations have released et al., 2018), among others. In addition, `zoom' simu- data with similar approaches, including Bolshoi and lation campaigns include NIHAO (Wang et al., 2015), MultiDark (CosmoSim; Klypin et al., 2011; Riebe FIRE-2 (Hopkins et al., 2018), and Auriga (Grand et al., 2013), DEUS (Rasera et al., 2010), and MICE et al., 2017), in addition to many others. These have (Cosmohub; Crocce et al., 2010). In contrast, some provided numerous additional insights into many ques- recent simulation projects have made group catalogs tions in galaxy evolution (recent progress reviewed in and/or snapshots available for direct download, in- Faucher-Gigu`ere, 2018). For instance, reionization sim- cluding MassiveBlack-II (Khandai et al., 2014), the ulations may be able to include explicit radiative trans- Dark Sky simulation (Skillman et al., 2014), ν2GC fer, and zoom simulations may be able to reach higher (Makiya et al., 2016), and Abacus (Garrison et al., resolutions and/or more rapidly explore model varia- 2018). Skies and Universes (Klypin et al., 2017) or- tions, in comparison to large cosmological volume sim- ganizes a number of such data releases. With respect ulations. to Illustris, the most comparable in simulation type, Observational efforts studying the properties of data complexity, and scientific scope is the recent pub- galaxies across cosmic time provide ever richer datasets. lic data release of the Eagle simulation, described in Surveys such as SDSS (York et al., 2000), CANDELS McAlpine et al.(2016) (see also Camps et al., 2018). (Grogin et al., 2011), 3D-HST (Brammer et al., 2012), The initial group catalog release was modeled on the LEGA-C (van der Wel et al., 2016), SINS/zC-SINF Millennium database architecture, and the raw snap- and KMOS3D (Genzel et al., 2014; Wisnioski et al., shot data was also subsequently made available (The 2015), KBSS (Steidel et al., 2014), and MOSDEF EAGLE team, 2017). More recently, significant in- (Kriek et al., 2015) provide local and high redshift frastructure research and development has focused on measurements of the statistical properties of galaxy providing remote computational resources, including populations. Complementary, spatially-resolved data the NOAO Data Lab (Fitzpatrick et al., 2014) and has recently become available from large, z = 0 IFU the SciServer project (Medvedev et al., 2016; Raddick surveys such as MANGA (Bundy et al., 2015), CAL- et al., 2017). Web-based orchestration projects also in- IFA (S´anchez et al., 2012) and SAMI (Bryant et al., clude Ragagnin et al.(2017), Tangos (Pontzen and 2015). Tremmel, 2018), and Jovial (Araya et al., 2018). In order to inform theoretical models using obser- The public release of IllustrisTNG (hereafter, TNG) vational constraints, as well as to interpret observa- follows upon and further develops tools and ideas pi- tional results using realistic cosmological models, pub- oneered in the original Illustris data release. We of- lic data dissemination from both observational and fer direct online access to all snapshot, group cata- simulation campaigns is required. Observational data release has a successful history dating back at least log, merger tree, and supplementary data catalog files. to the SDSS SkyServer (Szalay et al., 2000, 2002), In addition, we develop a web-based API which al- which provides tools for remote users to query and lows users to perform many common tasks without acquire large datasets (Gray et al., 2002; Szalay et al., the need to download any full data files. These include 2002). The still-in-use approach is based on user writ- searching over the group catalogs, extracting particle ten SQL queries, which provide search results as well data from the snapshots, accessing individual merger as data acquisition. From the theoretical community, trees, and requesting visualization and further data the public data release of the Millennium simulation analysis functions. Extensive documentation and pro- (Springel et al., 2005) was the first attempt of simi- grammatic examples (in the IDL, Python, and Matlab lar scale. Modeled on the SDSS approach, data was languages) are provided. stored in a relational database, with an immediately This paper is intended primarily as an overview recognizable SQL-query interface (Lemson and Virgo guide for TNG data users, describing updates and new Consortium, 2006). It has since been extended to in- features, while exhaustive documentation will be main- clude additional simulations, including Millennium-II tained online. In Section2 we give an overview of the (Boylan-Kolchin et al., 2009; Guo et al., 2011), and simulations. Section3 describes the data products, and a first attempt at the idea of a \virtual observatory" Section4 discusses methods for data access. In Sec- (VO) was realized (Overzier et al., 2013). The Theo- tion5 we present some scientific remarks and cautions, retical Astrophysical Observatory (TAO; Bernyk et al., while in Section6 we discuss community considera- 2014) was similarly focused around mock observations tions including citation requests. Section7 describes of simulated galaxy and galaxy survey data. Explo- technical details related to the data release architec- rations continue on how to best
Load more

Recommended publications
  • Dark Energy and Dark Matter As Inertial Effects Introduction
    Dark Energy and Dark Matter as Inertial Effects Serkan Zorba Department of Physics and Astronomy, Whittier College 13406 Philadelphia Street, Whittier, CA 90608 [email protected] ABSTRACT A disk-shaped universe (encompassing the observable universe) rotating globally with an angular speed equal to the Hubble constant is postulated. It is shown that dark energy and dark matter are cosmic inertial effects resulting from such a cosmic rotation, corresponding to centrifugal (dark energy), and a combination of centrifugal and the Coriolis forces (dark matter), respectively. The physics and the cosmological and galactic parameters obtained from the model closely match those attributed to dark energy and dark matter in the standard Λ-CDM model. 20 Oct 2012 Oct 20 ph] - PACS: 95.36.+x, 95.35.+d, 98.80.-k, 04.20.Cv [physics.gen Introduction The two most outstanding unsolved problems of modern cosmology today are the problems of dark energy and dark matter. Together these two problems imply that about a whopping 96% of the energy content of the universe is simply unaccounted for within the reigning paradigm of modern cosmology. arXiv:1210.3021 The dark energy problem has been around only for about two decades, while the dark matter problem has gone unsolved for about 90 years. Various ideas have been put forward, including some fantastic ones such as the presence of ghostly fields and particles. Some ideas even suggest the breakdown of the standard Newton-Einstein gravity for the relevant scales. Although some progress has been made, particularly in the area of dark matter with the nonstandard gravity theories, the problems still stand unresolved.
    [Show full text]
  • Galaxy Formation Simulations: "Sub-Grid" Vs. Physics
    GalaxyGalaxy formationformation simulations:simulations: "sub-grid""sub-grid" vs.vs. physicsphysics DeboraDebora SijackiSijacki IoAIoA && KICCKICC CambridgeCambridge Cosmic Mergers Workshop Birmingham Sept 22th 2017 Cosmological simulations of galaxy and structure formation 2 Provide ab initio physical understanding on all scales Standard (and less standard) ingredients: ► “simple” ΛCDM assumption (WDM, SIDM,…, evolving w,…, coupled DM+DE models,…) ► Newtonian gravity (dark matter and baryons) (relativistic corrections, modified gravity models,...) ► Ideal gas hydrodynamics + collisionless dynamics of stars (conduction, viscosity, MHD,…, stellar collisions, stellar hydro) ► Gas radiative cooling/heating, star & BH formation and feedback (non equlibrium low T cooling, dust, turbulence, GMCs,…) ► Reionization in form of an uniform UV background (simple accounting for the local sources,…, full RT on the fly) Pure dark matter simulations in ΛCDM cosmology 3 Millennium XXL 40 yrs! See also: Horizon Run 3 (Kim 2011) MultiDark (Prada 2012) DEUS (Alimi et al. 2012) Watson et al. 2013 The importance of baryons 4 Baryons are directly observable and they affect the underlying dark matter distribution (contraction/expansion/shape/bias, WL,...) => profound implications for cosmology SDSS, BOSS, eBOSS Hubble UDF composite DES WL The importance of baryons 5 Vast range of spatial scales involved and very complex, non-linear physics → SUB-GRID models (“free parameters” constrained by obs) Cosmic web Galaxies 109 pc 103 pc GMCs 10-100 pc Massive stars SNae SMBHs -8 -6 0.1 pc 10 - 10 pc < 10-6 pc Current state-of-the-art in cosmological hydro simulations 6 The Eagle Project (Schaye et al. 2015) The Horizon AGN project (Dubois et al. 14) Magneticum (Dolag et al.
    [Show full text]
  • A Statistical Framework for the Characterisation of WIMP Dark Matter with the LUX-ZEPLIN Experiment
    A statistical framework for the characterisation of WIMP dark matter with the LUX-ZEPLIN experiment Ibles Olcina Samblas Department of Physics A thesis submitted for the degree of Doctor of Philosophy November 2019 Abstract Several pieces of astrophysical evidence, from galactic to cosmological scales, indicate that most of the mass in the universe is composed of an invisible and essentially collisionless substance known as dark matter. A leading particle candidate that could provide the role of dark matter is the Weakly Interacting Massive Particle (WIMP), which can be searched for directly on Earth via its scattering off atomic nuclei. The LUX-ZEPLIN (LZ) experiment, currently under construction, employs a multi-tonne dual-phase xenon time projection chamber to search for WIMPs in the low background environment of the Davis Campus at the Sanford Underground Research Facility (South Dakota, USA). LZ will probe WIMP interactions with unprecedented sensitivity, starting to explore regions of the WIMP parameter space where new backgrounds are expected to arise from the elastic scattering of neutrinos off xenon nuclei. In this work the theoretical and computational framework underlying the calculation of the sensitivity of the LZ experiment to WIMP-nucleus scattering interactions is presented. After its planned 1000 live days of exposure, LZ will be able to achieve a 3σ discovery for spin independent cross sections above 3.0 10 48 cm2 at 40 GeV/c2 WIMP mass or exclude at × − 90% CL a cross section of 1.3 10 48 cm2 in the absence of signal. The sensitivity of LZ × − to spin-dependent WIMP-neutron and WIMP-proton interactions is also presented.
    [Show full text]
  • The Illustris Simulation: the Evolving Population of Black Holes Across Cosmic Time
    MNRAS 452, 575–596 (2015) doi:10.1093/mnras/stv1340 The Illustris simulation: the evolving population of black holes across cosmic time Debora Sijacki,1‹ Mark Vogelsberger,2 Shy Genel,3,4† Volker Springel,5,6 Paul Torrey,2,3,7 Gregory F. Snyder,8 Dylan Nelson3 and Lars Hernquist3 1Institute of Astronomy and Kavli Institute for Cosmology, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK 2Department of Physics, Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA 3Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA 4Department of Astronomy, Columbia University, 550 West 120th Street, New York, NY 10027, USA 5Heidelberg Institute for Theoretical Studies, Schloss-Wolfsbrunnenweg 35, D-69118 Heidelberg, Germany 6Zentrum fur¨ Astronomie der Universitat¨ Heidelberg, ARI, Monchhofstr.¨ 12-14, D-69120 Heidelberg, Germany Downloaded from 7Caltech, TAPIR, Mailcode 350-17, California Institute of Technology, Pasadena, CA 91125, USA 8Space Telescope Science Institute, 3700 San Martin Dr, Baltimore, MD 21218, USA Accepted 2015 June 12. Received 2015 June 12; in original form 2014 August 28 http://mnras.oxfordjournals.org/ ABSTRACT We study the properties of black holes and their host galaxies across cosmic time in the Illustris simulation. Illustris is a large-scale cosmological hydrodynamical simulation which resolves a (106.5 Mpc)3 volume with more than 12 billion resolution elements and includes state-of-the-art physical models relevant for galaxy formation. We find that the black hole mass density for redshifts z = 0–5 and the black hole mass function at z = 0 predicted by Illustris are in very good agreement with the most recent observational constraints.
    [Show full text]
  • Dark Energy and Dark Matter
    Dark Energy and Dark Matter Jeevan Regmi Department of Physics, Prithvi Narayan Campus, Pokhara [email protected] Abstract: The new discoveries and evidences in the field of astrophysics have explored new area of discussion each day. It provides an inspiration for the search of new laws and symmetries in nature. One of the interesting issues of the decade is the accelerating universe. Though much is known about universe, still a lot of mysteries are present about it. The new concepts of dark energy and dark matter are being explained to answer the mysterious facts. However it unfolds the rays of hope for solving the various properties and dimensions of space. Keywords: dark energy, dark matter, accelerating universe, space-time curvature, cosmological constant, gravitational lensing. 1. INTRODUCTION observations. Precision measurements of the cosmic It was Albert Einstein first to realize that empty microwave background (CMB) have shown that the space is not 'nothing'. Space has amazing properties. total energy density of the universe is very near the Many of which are just beginning to be understood. critical density needed to make the universe flat The first property that Einstein discovered is that it is (i.e. the curvature of space-time, defined in General possible for more space to come into existence. And Relativity, goes to zero on large scales). Since energy his cosmological constant makes a prediction that is equivalent to mass (Special Relativity: E = mc2), empty space can possess its own energy. Theorists this is usually expressed in terms of a critical mass still don't have correct explanation for this but they density needed to make the universe flat.
    [Show full text]
  • Gravitational Waves from Resolvable Massive Black Hole Binary Systems
    Mon. Not. R. Astron. Soc. 000, 000–000 (0000) Printed 22 October 2018 (MN LATEX style file v2.2) Gravitational waves from resolvable massive black hole binary systems and observations with Pulsar Timing Arrays A. Sesana1, A. Vecchio2 and M. Volonteri3 1Center for Gravitational Wave Physics, The Pennsylvania State University, University Park, PA 16802, USA 2School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK 3 Dept. of Astronomy, University of Michigan, Ann Arbor, MI 48109, USA Received — ABSTRACT Massive black holes are key components of the assembly and evolution of cosmic structures and a number of surveys are currently on-going or planned to probe the demographics of these objects and to gain insight into the relevant physical processes. Pulsar Timing Arrays (PTAs) currently provide the only means to observe gravita- > 7 tional radiation from massive black hole binary systems with masses ∼ 10 M⊙. The whole cosmic population produces a stochastic background that could be detectable with upcoming Pulsar Timing Arrays. Sources sufficiently close and/or massive gener- ate gravitational radiation that significantly exceeds the level of the background and could be individually resolved. We consider a wide range of massive black hole binary assembly scenarios, we investigate the distribution of the main physical parameters of the sources, such as masses and redshift, and explore the consequences for Pulsar Timing Arrays observations. Depending on the specific massive black hole population model, we estimate that on average at least one resolvable source produces timing residuals in the range ∼ 5 − 50 ns. Pulsar Timing Arrays, and in particular the future Square Kilometre Array (SKA), can plausibly detect these unique systems, although the events are likely to be rare.
    [Show full text]
  • Can an Axion Be the Dark Energy Particle?
    Kuwait53 J. Sci.Can 45 an(3) axion pp 53-56, be the 2018 dark energy particle? Can an axion be the dark energy particle? Elias C. Vagenas Theoretical Physics Group, Department of Physics Kuwait University, P.O. Box 5969, Safat 13060, Kuwait [email protected] Abstract Following a phenomenological analysis done by the late Martin Perl for the detection of the dark energy, we show that an axion of energy can be a viable candidate for the dark energy particle. In particular, we obtain the characteristic length and frequency of the axion as a quantum particle. Then, employing a relation that connects the energy density with the frequency of a particle, i.e., , we show that the energy density of axions, with the aforesaid value of mass, as obtained from our theoretical analysis is proportional to the dark energy density computed on observational data, i.e., . Keywords: Axion, axion-like particles, dark energy, dark energy particle 1. Introduction Therefore, though the energy density of the electric field, i.e., One of the most important and still unsolved problem in , can be detected and measured, the dark energy density, contemporary physics is related to the energy content of the i.e., , which is much larger has not been detected yet. universe. According to the recent results of the 2015 Planck Of course, one has to avoid to make an experiment for the mission (Ade et al., 2016), the universe roughly consists of detection and measurement of the dark energy near the 69.11% dark energy, 26.03% dark matter, and 4.86% baryonic surface of the Earth, or the Sun, or the planets, since the (ordinary) matter.
    [Show full text]
  • Astrophysical Uncertainties of Direct Dark Matter Searches
    Technische Universit¨atM¨unchen Astrophysical uncertainties of direct dark matter searches Dissertation by Andreas G¨unter Rappelt Physik Department, T30d & Collaborative Research Center SFB 1258 “Neutrinos and Dark Matter in Astro- and Particlephysics” Technische Universit¨atM¨unchen Physik Department T30d Astrophysical uncertainties of direct dark matter searches Andreas G¨unter Rappelt Vollst¨andigerAbdruck der von der Fakult¨atf¨urPhysik der Technischen Universit¨at M¨unchen zur Erlangung des akademischen Grades eines Doktors der Naturwissenschaften genehmigten Dissertation. Vorsitzender: Prof. Dr. Lothar Oberauer Pr¨uferder Dissertation: 1. Prof. Dr. Alejandro Ibarra 2. Prof. Dr. Bj¨ornGarbrecht Die Dissertation wurde am 12.11.2019 bei der Technischen Universit¨at M¨unchen eingereicht und durch die Fakult¨atf¨urPhysik am 24.01.2020 angenommen. Abstract Although the first hints towards dark matter were discovered almost 100 years ago, little is known today about its properties. Also, dark matter has so far only been inferred through astronomical and cosmological observations. In this work, we therefore investi- gate the influence of astrophysical assumptions on the interpretation of direct searches for dark matter. For this, we assume that dark matter is a weakly interacting massive particle. First, we discuss the development of a new analysis method for direct dark matter searches. Starting from the decomposition of the dark matter velocity distribu- tion into streams, we present a method that is completely independent of astrophysical assumptions. We extend this by using an effective theory for the interaction of dark matter with nucleons. This allows to analyze experiments with minimal assumptions on the particle physics of dark matter. Finally, we improve our method so that arbitrarily strong deviations from a reference velocity distribution can be considered.
    [Show full text]
  • Dark Energy and CMB
    Dark Energy and CMB Conveners: S. Dodelson and K. Honscheid Topical Conveners: K. Abazajian, J. Carlstrom, D. Huterer, B. Jain, A. Kim, D. Kirkby, A. Lee, N. Padmanabhan, J. Rhodes, D. Weinberg Abstract The American Physical Society's Division of Particles and Fields initiated a long-term planning exercise over 2012-13, with the goal of developing the community's long term aspirations. The sub-group \Dark Energy and CMB" prepared a series of papers explaining and highlighting the physics that will be studied with large galaxy surveys and cosmic microwave background experiments. This paper summarizes the findings of the other papers, all of which have been submitted jointly to the arXiv. arXiv:1309.5386v2 [astro-ph.CO] 24 Sep 2013 2 1 Cosmology and New Physics Maps of the Universe when it was 400,000 years old from observations of the cosmic microwave background and over the last ten billion years from galaxy surveys point to a compelling cosmological model. This model requires a very early epoch of accelerated expansion, inflation, during which the seeds of structure were planted via quantum mechanical fluctuations. These seeds began to grow via gravitational instability during the epoch in which dark matter dominated the energy density of the universe, transforming small perturbations laid down during inflation into nonlinear structures such as million light-year sized clusters, galaxies, stars, planets, and people. Over the past few billion years, we have entered a new phase, during which the expansion of the Universe is accelerating presumably driven by yet another substance, dark energy. Cosmologists have historically turned to fundamental physics to understand the early Universe, successfully explaining phenomena as diverse as the formation of the light elements, the process of electron-positron annihilation, and the production of cosmic neutrinos.
    [Show full text]
  • The Illustristng Simulations: Public Data Release
    Nelson et al. Computational Astrophysics and Cosmology (2019)6:2 https://doi.org/10.1186/s40668-019-0028-x R E S E A R C H Open Access The IllustrisTNG simulations: public data release Dylan Nelson1*,VolkerSpringel1,6,7, Annalisa Pillepich2, Vicente Rodriguez-Gomez8,PaulTorrey9,5, Shy Genel4, Mark Vogelsberger5, Ruediger Pakmor1,6, Federico Marinacci10,5, Rainer Weinberger3, Luke Kelley11,MarkLovell12,13, Benedikt Diemer3 and Lars Hernquist3 Abstract We present the full public release of all data from the TNG100 and TNG300 simulations of the IllustrisTNG project. IllustrisTNG is a suite of large volume, cosmological, gravo-magnetohydrodynamical simulations run with the moving-mesh code AREPO. TNG includes a comprehensive model for galaxy formation physics, and each TNG simulation self-consistently solves for the coupled evolution of dark matter, cosmic gas, luminous stars, and supermassive black holes from early time to the present day, z = 0. Each of the flagship runs—TNG50, TNG100, and TNG300—are accompanied by halo/subhalo catalogs, merger trees, lower-resolution and dark-matter only counterparts, all available with 100 snapshots. We discuss scientific and numerical cautions and caveats relevant when using TNG. The data volume now directly accessible online is ∼750 TB, including 1200 full volume snapshots and ∼80,000 high time-resolution subbox snapshots. This will increase to ∼1.1 PB with the future release of TNG50. Data access and analysis examples are available in IDL, Python, and Matlab. We describe improvements and new functionality in the web-based API, including on-demand visualization and analysis of galaxies and halos, exploratory plotting of scaling relations and other relationships between galactic and halo properties, and a new JupyterLab interface.
    [Show full text]
  • Machine Learning and Cosmological Simulations I: Semi-Analytical Models
    MNRAS 000,1{18 (2015) Preprint 20 August 2018 Compiled using MNRAS LATEX style file v3.0 Machine Learning and Cosmological Simulations I: Semi-Analytical Models Harshil M. Kamdar1;2?, Matthew J. Turk2;4 and Robert J. Brunner2;3;4;5 1Department of Physics, University of Illinois, Urbana, IL 61801 USA 2Department of Astronomy, University of Illinois, Urbana, IL 61801 USA 3Department of Statistics, University of Illinois, Champaign, IL 61820 USA 4National Center for Supercomputing Applications, Urbana, IL 61801 USA 5Beckman Institute For Advanced Science and Technology, University of Illinois, Urbana, IL, 61801 USA Accepted 2015 October 1. Received 2015 September 30; in original form 2015 July 2 ABSTRACT We present a new exploratory framework to model galaxy formation and evolution in a hierarchical universe by using machine learning (ML). Our motivations are two- fold: (1) presenting a new, promising technique to study galaxy formation, and (2) quantitatively analyzing the extent of the influence of dark matter halo properties on galaxies in the backdrop of semi-analytical models (SAMs). We use the influential Millennium Simulation and the corresponding Munich SAM to train and test vari- ous sophisticated machine learning algorithms (k-Nearest Neighbors, decision trees, random forests and extremely randomized trees). By using only essential dark matter 12 halo physical properties for haloes of M > 10 M and a partial merger tree, our model predicts the hot gas mass, cold gas mass, bulge mass, total stellar mass, black hole mass and cooling radius at z = 0 for each central galaxy in a dark matter halo for the Millennium run. Our results provide a unique and powerful phenomenolog- ical framework to explore the galaxy-halo connection that is built upon SAMs and demonstrably place ML as a promising and a computationally efficient tool to study small-scale structure formation.
    [Show full text]
  • Marcia Rieke Programs Subcommittee Chair Astro2010
    Decadal Surveys: What Are They and Why Do They Matter? Marcia Rieke Programs Subcommittee Chair Astro2010 What Are Decadal Surveys? • In the 1960s, astronomers realized 1st Survey that their aspirations required so in 1964 much federal funding that some type of assessment and recommendations were needed • Initially only astronomers did this 1982 and now all of the disciplines in space science conduct surveys with some participation from other agencies 1991 • Surveys and “CATE” are congressionally mandated 1972 2001 2010 2 U.S. Decadal Surveys -1 • 1964: Ground-based Astronomy: A Ten Year Program (Whitford) QSOs had just been discovered -- resulted in construction of CTIO 4-meter • 1972: Astronomy and Astrophysics for the 1970s (Greenstein) Astronomy satellites used to discover X-ray emission from stars -- resulted in construction of the VLA, HEAOs, and development work for HST • 1982: Astronomy and Astrophysics for the 1980s (Field) Many galaxies observed to produce large amounts of IR emission -- resulted in construction of Chandra and VLBI -- for future study: “Long-duration space flights of IR telescopes cooled to cryogenic temperatures” 3 U.S. Decadal Surveys -2 • 1991: The Decade of Discovery in Astronomy and Astrophysics (Bahcall) Existence of dark matter demonstrated -- resulted in construction of Spitzer, SOFIA, Gemini • 2001: Astronomy and Astrophysics in the New Millennium (McKee-Taylor) First exo-planets discovered, first evidence of dark energy seen -- resulted in development of JWST (and reassessment of how to execute decadal surveys) • 2010: New Worlds, New Horizons [“Astro2010”] (Blandford) First direct images of exo-planets, GRB afterglows observed, SMBHs in nuclei of virtually all galaxiex -- resulted in construction start for LSST, work on WFIRST Astro2010 Executive Committee Why There Are Decadal Surveys Astronomers want to do more than the federal budget can support: Once this fact is acknowledged, then the discussion turns to who should decide what is to be done, what are the rules and criteria.
    [Show full text]