The Diversity and Variability of Star Formation Histories in Different Simulations
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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. -
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. -
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. -
The Hi Velocity Function: a Test of Cosmology Or Baryon Physics?
MNRAS 000,1{19 (2019) Preprint 18 July 2019 Compiled using MNRAS LATEX style file v3.0 The Hi Velocity Function: a test of cosmology or baryon physics? Garima Chauhan,1;2? Claudia del P. Lagos,1;2 Danail Obreschkow,1;2 Chris Power,1;2 Kyle Oman,3 Pascal J. Elahi,1;2 1International Centre for Radio Astronomy Research (ICRAR), 7 Fairway, Crawley, WA 6009, Australia. 2ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D), Australia. 3Kapteyn Institute,Landleven 12, 9747 AD Groningen, Netherlands. Accepted XXX. Received YYY; in original form ZZZ ABSTRACT Accurately predicting the shape of the Hi velocity function of galaxies is regarded widely as a fundamental test of any viable dark matter model. Straightforward anal- yses of cosmological N-body simulations imply that the ΛCDM model predicts an overabundance of low circular velocity galaxies when compared to observed Hi ve- locity functions. More nuanced analyses that account for the relationship between galaxies and their host haloes suggest that how we model the influence of baryonic processes has a significant impact on Hi velocity function predictions. We explore this in detail by modelling Hi emission lines of galaxies in the Shark semi-analytic galaxy formation model, built on the surfs suite of ΛCDM N-body simulations. We create a simulated ALFALFA survey, in which we apply the survey selection function and account for effects such as beam confusion, and compare simulated and observed Hi velocity width distributions, finding differences of . 50%, orders of magnitude smaller than the discrepancies reported in the past. -
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. -
The Connection Between Galaxy Stellar Masses and Dark Matter
The Connection Between Galaxy Stellar Masses and Dark Matter Halo Masses: Constraints from Semi-Analytic Modeling and Correlation Functions by Catherine E. White A dissertation submitted to The Johns Hopkins University in conformity with the requirements for the degree of Doctor of Philosophy. Baltimore, Maryland August, 2016 c Catherine E. White 2016 ⃝ All rights reserved Abstract One of the basic observations that galaxy formation models try to reproduce is the buildup of stellar mass in dark matter halos, generally characterized by the stellar mass-halo mass relation, M? (Mhalo). Models have difficulty matching the < 11 observed M? (Mhalo): modeled low mass galaxies (Mhalo 10 M ) form their stars ∼ ⊙ significantly earlier than observations suggest. Our goal in this thesis is twofold: first, work with a well-tested semi-analytic model of galaxy formation to explore the physics needed to match existing measurements of the M? (Mhalo) relation for low mass galaxies and second, use correlation functions to place additional constraints on M? (Mhalo). For the first project, we introduce idealized physical prescriptions into the semi-analytic model to test the effects of (1) more efficient supernova feedback with a higher mass-loading factor for low mass galaxies at higher redshifts, (2) less efficient star formation with longer star formation timescales at higher redshift, or (3) less efficient gas accretion with longer infall timescales for lower mass galaxies. In addition to M? (Mhalo), we examine cold gas fractions, star formation rates, and metallicities to characterize the secondary effects of these prescriptions. ii ABSTRACT The technique of abundance matching has been widely used to estimate M? (Mhalo) at high redshift, and in principle, clustering measurements provide a powerful inde- pendent means to derive this relation. -
Photometric Survey for Dwarf Galaxies Within Intergalactic Voids Rochelle
Photometric Survey for Dwarf Galaxies Within Intergalactic Voids Rochelle Steele A senior thesis submitted to the faculty of Brigham Young University in partial fulfillment of the requirements for the degree of Bachelor of Science J. Ward Moody, Advisor Department of Physics and Astronomy Brigham Young University April 2019 Copyright © 2019 Rochelle Steele All Rights Reserved ABSTRACT Photometric Survey for Dwarf Galaxies Within Intergalactic Voids Rochelle Steele Department of Physics and Astronomy, BYU Bachelor of Science No astronomer has yet discovered the dwarf galaxies that many L Cold Dark Matter (LCDM) simulations predict should be abundant within intergalactic voids. Spectroscopic observations are necessary to identify and determine the distances to these galaxies. However, dwarf galaxies are so faint that it is difficult to observe them with spectroscopic methods. We have developed a way to photometrically identify dwarf galaxies and estimate their distance using three narrowband filters centered on the Ha emission line. From this method, the redshift of the Ha emission line can be estimated, which gives the distance to the galaxy. Equivalent width, or strength, of the emission line detected can also be estimated. The line observed must be verified as Ha emission using observations with Sloan broadband filters. We have primarily studied one void, FN8, using these methods and have found 14 candidate dwarf galaxies, which must still be confirmed spectroscopically. The low density of candidate void galaxies rejects the hypothesis that there is a uniform distribution of dwarf galaxies within the void, as suggested by some LCDM simulations. Keywords: large-scale structure, voids, dwarf galaxies, dark matter, LCDM ACKNOWLEDGMENTS I would first like to thank my advisor, Dr. -
Jhep07(2020)081
Published for SISSA by Springer Received: February 10, 2020 Revised: May 28, 2020 Accepted: June 9, 2020 Published: July 13, 2020 Impact of uncertainties in the halo velocity profile on JHEP07(2020)081 direct detection of sub-GeV dark matter Andrzej Hryczuk,a Ekaterina Karukes,b Leszek Roszkowskib;a and Matthew Taliab aNational Centre for Nuclear Research, Pasteura 7, Warsaw 02-093, Poland bAstroCeNT, Nicolaus Copernicus Astronomical Center Polish Academy of Sciences, ul. Rektorska 4, Warsaw 00-614, Poland E-mail: [email protected], [email protected], [email protected], [email protected] Abstract: We use the state-of-the-art high-resolution cosmological simulations by Illus- trisTNG to derive the velocity distribution and local density of dark matter in galaxies like our Milky Way and find a substantial spread in both quantities. Next we use our find- ings to examine the sensitivity to the dark matter velocity profile of underground searches using electron scattering in germanium and silicon targets. We find that sub-GeV dark matter search is strongly affected by these uncertainties, unlike nuclear recoil searches for heavier dark matter, especially in multiple electron-hole modes, for which the sensitivity to the scattering cross-section is also weaker. Therefore, by improving the sensitivity to lower ionization thresholds not only projected sensitivities will be boosted but also the dependence on the astrophysical uncertainties will become significantly reduced. Keywords: Cosmology of Theories beyond the SM, Beyond Standard Model ArXiv ePrint: 2001.09156 Open Access, c The Authors. https://doi.org/10.1007/JHEP07(2020)081 Article funded by SCOAP3. -
Physics Beyond Standard Model
Physics Beyond Standard Model • Standard Model • Neutrino Search • Big Bang Dark Matter • Big Bang Dark Energy • Quantum entanglement ( 量子纠缠 ) J. Ulbricht ETHZ Lecture USTC 2017 1 OUTLINE • History of Big Bang and Dark matter observations • Transition SM to Big Bang • PARAMETERS of Lambda-CDM model • Evolution of the COSMOS • The parameters of the ΛCDM model get restricted by 8 observations • Experimental search for Dark Matter • Conclusion 2 History of Big Bang and Dark matter observations • 1908 Walter S. Adams use first the “term red-shift”. • 1912 Vesto Sliper discovered most spiral nebula had red shift. • 1922 E. Hubbel and a. Friedman introduced the Hubble law and the Friedman equations. • 1932 Jian Oort studied stellar motions in neighbourhood galaxies and found that the mass on the galactic plane must be more as the visible mass. • 1933 Fritz Zwicky studied the stability of the COMA cluster and found evidence of unseen mass. He inferred that a non-visible mass must exist which provides enough mass and gravity to hold the cluster together. • 1948 R. Alpher and R. Herman predicted the Micro Wave background. • 1978 A. Penzieas and R. W. Wilson got Nobel Price for discovery of 2.7 K Micro Wave background. • 1960 – 1980 The observations and calculations of Vera Rubin and Kent Ford showed that most galaxies must contain about ten times more mass as can be accounted for visible stars to explain the galactic rotation curves. • 1997 The DAMA experiment in Gand Sasso reported about an annual modulation signature over many annual cycles. • 2012 Lensing observations identify a filament of dark matter between two clusters of galaxies. -
Dark Energy Survey Year 3 Results: Multi-Probe Modeling Strategy and Validation
DES-2020-0554 FERMILAB-PUB-21-240-AE Dark Energy Survey Year 3 Results: Multi-Probe Modeling Strategy and Validation E. Krause,1, ∗ X. Fang,1 S. Pandey,2 L. F. Secco,2, 3 O. Alves,4, 5, 6 H. Huang,7 J. Blazek,8, 9 J. Prat,10, 3 J. Zuntz,11 T. F. Eifler,1 N. MacCrann,12 J. DeRose,13 M. Crocce,14, 15 A. Porredon,16, 17 B. Jain,2 M. A. Troxel,18 S. Dodelson,19, 20 D. Huterer,4 A. R. Liddle,11, 21, 22 C. D. Leonard,23 A. Amon,24 A. Chen,4 J. Elvin-Poole,16, 17 A. Fert´e,25 J. Muir,24 Y. Park,26 S. Samuroff,19 A. Brandao-Souza,27, 6 N. Weaverdyck,4 G. Zacharegkas,3 R. Rosenfeld,28, 6 A. Campos,19 P. Chintalapati,29 A. Choi,16 E. Di Valentino,30 C. Doux,2 K. Herner,29 P. Lemos,31, 32 J. Mena-Fern´andez,33 Y. Omori,10, 3, 24 M. Paterno,29 M. Rodriguez-Monroy,33 P. Rogozenski,7 R. P. Rollins,30 A. Troja,28, 6 I. Tutusaus,14, 15 R. H. Wechsler,34, 24, 35 T. M. C. Abbott,36 M. Aguena,6 S. Allam,29 F. Andrade-Oliveira,5, 6 J. Annis,29 D. Bacon,37 E. Baxter,38 K. Bechtol,39 G. M. Bernstein,2 D. Brooks,31 E. Buckley-Geer,10, 29 D. L. Burke,24, 35 A. Carnero Rosell,40, 6, 41 M. Carrasco Kind,42, 43 J. Carretero,44 F. J. Castander,14, 15 R. -
Prospects for Dark Matter Detec- Tion with Next Generation Neutrino Telescopes
Prospects for dark matter detec- tion with next generation neutrino telescopes MSc thesis in Physics and Astronomy ANTON BÄCKSTRÖM Department of Physics CHALMERS UNIVERSITY OF TECHNOLOGY Göteborg 2018 Masters thesis 2018: Prospects for dark matter detection with next generation neutrino telescopes ANTON BÄCKSTRÖM Department of Physics Chalmers University of Technology Göteborg 2018 Prospects for dark matter detection with next generation neutrino telescopes ANTON BÄCKSTRÖM © ANTON BÄCKSTRÖM, 2018. Supervisor: Riccardo Catena, Department of Physics Examiner: Ulf Gran, Department of Physics Department of Physics Chalmers University of Technology SE-412 96 Göteborg Telephone +46 31 772 1000 Typeset in LATEX Printed by Chalmers reproservice Göteborg, 2018 iv Prospects for dark matter detection with next generation neutrino telescopes ANTON BÄCKSTRÖM Department of Physics Chalmers University of Technology Abstract There are strong hints that around a fourth of the energy content of the Universe is made up of dark matter. This type of matter is invisible to us, since it does not interact via the electromagnetic force. One of the leading theories suggests that this type of matter consists of Weakly Interacting Massive Particles (WIMPs), particles with mass around 10-1000 GeV that only interact with baryonic matter via the weak nuclear force and gravitation. If this theory is true, dark matter should be grav- itationally attracted toward the Sun, inside which collisions with baryonic matter have a possibility to slow down the particles to speeds below the escape velocity. As these dark matter particles are captured by the Sun, they will continue to collide with baryonic particles and lose more energy until they settle in the core of the Sun. -
Cold Dark Matter's Not Enough
COLD DARK MATTER’S NOT ENOUGH PIERO MADAU UC SANTA CRUZ MADRID 2015 JUST SIX NUMBERS (FLAT ΛCDM) ΛCDM (PLANCK 2015, TT,TE,EE+lowP+lensing+ext) 2 Ωbh = 0.02230±0.00014 2 ΩXh = 0.1188±0.0010 100θMC = 1.04093± 0.00030 τ = 0.066 ± 0.012 ns = 0.9667±0.0040 σ8 = 0.8159 ± 0.0086 A 160σ measurement of the cosmic baryon density and a 120σ detection of non-baryonic DM! DENSITY FLUCTUATIONS DATA AGREE WITH ΛCDM DWARF GALAXIES GALAXY CORES MILLILENSING Hlozek/Primack SUBSTRUCTURE: A UNIQUE PREDICTION OF ΛCDM Subhalo differential mass function has slope −1.9 ➪ equal mass per decade of mass In a MW-sized halo at z=0: 5-10% of host mass locked in self-bound subhalos SUBSTRUCTURE: A UNIQUE PREDICTION OF ΛCDM Subhalo differential mass function has slope −1.9 ➪ equal mass per decade of mass In a MW-sized halo at z=0: 5-10% of host mass locked in self-bound subhalos DWARF GAALAXYBUNDANCE PROBLEM VS. STRUCTURAL MISMATCH DARK GALAXIES? CUSP/CORE PROBLEM THEORY: Nsub≈1,000 OBSERVATIONS: Nsat≈25 w Vc(infall)≳10 km/s SOLUTIONS TO THE DGP: 1) BLAME “GASTROPHYSICS" 2) BLAME CDM mX=100 GeV mX=2 keV mX=30 eV Late-time linear power spectra for density perturbations in universes dominated by hot, warm and cold dark matter. Lovell et al. 2014 LYMAN-ALPHA FOREST SPECTRA: CDM VS. WDM High-frequency power missing in WDM! Viel et al. 2013 SOMEONE LIKES IT COLD/TEPID High-resolution Keck and Magellan spectra match ΛCDM up to z = 5.4! 2σ lower limit on the mass of a thermal relic: mWDM > 3.3 keV ➩ MFS < 8 3×10 M⦿ mWDM=2 keV at 4σ C.L.