Environmental dependence of halo formation times Geraint Harker.

Slides:



Advertisements
Similar presentations
Building a Mock Universe Cosmological nbody dark matter simulations + Galaxy surveys (SDSS, UKIDSS, 2dF) Access to mock catalogues through VO Provide analysis.
Advertisements

Quasar Clustering from SDSS DR7: Dependencies on FIRST Radio Magnitudes Andria C. Schwortz, Sarah Eftekharzadeh, Adam D. Myers, Yue Shen Clustering is.
Lesson Inferences Between Two Variables. Objectives Perform Spearman’s rank-correlation test.
Astro-2: History of the Universe Lecture 4; April
Galaxy Formation, Theory and Modelling Shaun Cole (ICC, Durham) 25 th October 2007 ICC Photo: Malcolm Crowthers Collaborators: Geraint Harker John Helly.
Why Environment Matters more massive halos. However, it is usually assumed in, for example, semianalytic modelling that the merger history of a dark matter.
Correlation and Autocorrelation
Press-Schechter Formalism: Structure Formation by Self-Similar Condensation Jean P. Walker Based on Press & Schechter’s 1974 Paper.
Statistical Properties of Radio Galaxies in the local Universe Yen-Ting Lin Princeton University Pontificia Universidad Católica de Chile Yue Shen, Michael.
Carlos Guillermo Bornancini IATE Group, Observatorio Astronómico Córdoba The Spatial Clustering of Ultra Steep Spectrum radio sources and galaxies. Carlos.
Don’t spam class lists!!!. Farshad has prepared a suggested format for you final project. It will be on the web
The STAGES Supercluster: A challenge for semi-analytical models? Rhys Rhodes The University of Nottingham 25 th June 2008 Meghan Gray and Frazer Pearce.
High Redshift Galaxies (Ever Increasing Numbers).
Angular clustering and halo occupation properties of COSMOS galaxies Cristiano Porciani.
Clustering of QSOs and X-ray AGN at z=1 Alison Coil Hubble Fellow University of Arizona October 2007 Collaborators: Jeff Newman, Joe Hennawi, Marc Davis,
Cosmological constraints from models of galaxy clustering Abstract Given a dark matter distribution, the halo occupation distribution (HOD) provides a.
Galaxy-Galaxy Lensing What did we learn? What can we learn? Henk Hoekstra.
The Theory/Observation connection lecture 3 the (non-linear) growth of structure Will Percival The University of Portsmouth.
AGN downsizing は階層的銀河形成論で 説明できるか? Motohiro Enoki Tomoaki Ishiyama (Tsukuba Univ.) Masakazu A. R. Kobayashi (Ehime Univ.) Masahiro Nagashima (Nagasaki Univ.)
Correlation.
TIG session 3+Millennium database Millennium Database Overview and some first usage experiences Gerard Lemson and the Virgo Consortium astro-ph/
Galaxy bias with Gaussian/non- Gaussian initial condition: a pedagogical introduction Donghui Jeong Texas Cosmology Center The University of Texas at Austin.
Non-parametric Tests. With histograms like these, there really isn’t a need to perform the Shapiro-Wilk tests!
Environmental Properties of a Sample of Starburst Galaxies Selected from the 2dFGRS Matt Owers (UNSW) Warrick Couch (UNSW) Chris Blake (UBC) Michael Pracy.
W  eν The W->eν analysis is a phi uniformity calibration, and only yields relative calibration constants. This means that all of the α’s in a given eta.
The Halo Model Structure formation: cosmic capitalism Halos: abundances, clustering and evolution Galaxies: a nonlinear biased view of dark matters Marked.
Lecture 3 A Brief Review of Some Important Statistical Concepts.
Fundamentals of Data Analysis Lecture 10 Management of data sets and improving the precision of measurement pt. 2.
What can we learn from galaxy clustering? David Weinberg, Ohio State University Berlind & Weinberg 2002, ApJ, 575, 587 Zheng, Tinker, Weinberg, & Berlind.
The Black-Hole – Halo Mass Relation and High Redshift Quasars Stuart Wyithe Avi Loeb (The University of Melbourne) (Harvard University) Fan et al. (2001)
© 2011 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license.
Galaxy clustering II 2-point correlation function 5 Feb 2013.
INF380 - Proteomics-101 INF380 – Proteomics Chapter 10 – Spectral Comparison Spectral comparison means that an experimental spectrum is compared to theoretical.
MARK CORRELATIONS AND OPTIMAL WEIGHTS ( Cai, Bernstein & Sheth 2010 )
The coordinated growth of stars, haloes and large-scale structure since z=1 Michael Balogh Department of Physics and Astronomy University of Waterloo.
Theoretical Predictions about the Cold- Warm Gas Size around Cluster Galaxies using MgII systems Iván Lacerna VII Reunión Anual, SOCHIAS 2009 January 14.
Modeling the dependence of galaxy clustering on stellar mass and SEDs Lan Wang Collaborators: Guinevere Kauffmann (MPA) Cheng Li (MPA/SHAO, USTC) Gabriella.
Effects of correlation between halo merging steps J. Pan Purple Mountain Obs.
Environmental Effect on Mock Galaxy Quantities Juhan Kim, Yun-Young Choi, & Changbom Park Korea Institute for Advanced Study 2007/02/21.
MNRAS, submitted. Galaxy evolution Evolution in global properties reasonably well established What drives this evolution? How does it depend on environment?
Gravitational Lensing and Quasars “A man should look for what is, and not what he thinks should be.” – Albert Einstein Arvind Haran and David Johnston.
Zheng Dept. of Astronomy, Ohio State University David Weinberg (Advisor, Ohio State) Andreas Berlind (NYU) Josh Frieman (Chicago) Jeremy Tinker (Ohio State)
Zheng I N S T I T U T E for ADVANCED STUDY Cosmology and Structure Formation KIAS Sep. 21, 2006.
Xiaohu Yang (SJTU/SHAO) With: H. Wang, H.J. Mo, Y.P. Jing, F.C van den Bosch, W.P. Lin, D. Tweed… , KIAS Exploring the Local Universe with re-
Selecting a mass function by way of the Bayesian Razor Darell Moodley (UKZN), Dr. Kavilan Moodley (UKZN), Dr. Carolyn Sealfon (WCU)
Eyal Neistein Dec 2012 MS workshop Modeling galaxy clustering and weak gravitational lensing with the Millennium simulation Eyal Neistein TMoX group, MPE.
Population of Dark Matter Subhaloes Department of Astronomy - UniPD INAF - Observatory of Padova Carlo Giocoli prof. Giuseppe Tormen May Blois.
Copyright © 2010 Pearson Education, Inc. Chapter 16 Galaxies and Dark Matter Lecture Outline.
Luminous Red Galaxies in the SDSS Daniel Eisenstein ( University of Arizona) with Blanton, Hogg, Nichol, Tegmark, Wake, Zehavi, Zheng, and the rest of.
Agronomic Spatial Variability and Resolution What is it? How do we describe it? What does it imply for precision management?
联 合 天 体 物 理 中 心 Joint Center for Astrophysics The half-light radius distribution of LBGs and their stellar mass function Chenggang Shu Joint Center for.
Present-Day Descendants of z=3.1 Ly  Emitting (LAE) Galaxies in the Millennium-II Halo Merger Trees Jean P. Walker Soler – Rutgers University Eric Gawiser.
CHAPTER – 1 UNCERTAINTIES IN MEASUREMENTS. 1.3 PARENT AND SAMPLE DISTRIBUTIONS  If we make a measurement x i in of a quantity x, we expect our observation.
Chapter Eleven Performing the One-Sample t-Test and Testing Correlation.
We created a set of volume limited samples taken from the 2dFGRS (Colless 2001) that contains about 250,000 galaxies with accurate redshifts, is relatively.
KASI Galaxy Evolution Journal Club A Massive Protocluster of Galaxies at a Redshift of z ~ P. L. Capak et al. 2011, Nature, in press (arXive: )
Spatial Analysis Variogram
Chapter 25 Galaxies and Dark Matter. 25.1Dark Matter in the Universe 25.2Galaxy Collisions 25.3Galaxy Formation and Evolution 25.4Black Holes in Galaxies.
Two-Sample-Means-1 Two Independent Populations (Chapter 6) Develop a confidence interval for the difference in means between two independent normal populations.
Large scale structure in the SDSS
Clustering and environments of dark matter halos
Clustering properties and environment of AGN
Semi-Numerical Simulations of
Inferences Between Two Variables
Yongmin Yoon, Myungshin Im, Gwang-ho Lee, Gu Lim, and Seong-kook Lee
Volume 5, Issue 4, Pages e4 (October 2017)
Modeling the dependence of galaxy clustering on stellar mass and SEDs
Geology Geomath Chapter 7 - Statistics tom.h.wilson
These probabilities are the probabilities that individual values in a sample will fall in a 50 gram range, and thus represent the integral of individual.
Skills 5. Skills 5 Standard deviation What is it used for? This statistical test is used for measuring the degree of dispersion. It is another way.
Presentation transcript:

Environmental dependence of halo formation times Geraint Harker

Motivation Assumptions about the environmental dependence of halo formation times are implicit in semi-analytic models: Assumptions about the environmental dependence of halo formation times are implicit in semi-analytic models: In merger trees based on extended Press-Schechter theory the distribution of formation redshifts is a function only of the mass of a halo, and not of its environment. In merger trees based on extended Press-Schechter theory the distribution of formation redshifts is a function only of the mass of a halo, and not of its environment. Even if not manifested in spatially-averaged quantities, the dependence could become important when considering e.g. clustering statistics. Even if not manifested in spatially-averaged quantities, the dependence could become important when considering e.g. clustering statistics.

Calculation of formation redshift Consider parent halos with 64 or more particles in the merger trees calculated by John Helly using the SubFind groups. Consider parent halos with 64 or more particles in the merger trees calculated by John Helly using the SubFind groups. Starting at the final snapshot, move back slice by slice, and at each stage: Starting at the final snapshot, move back slice by slice, and at each stage: Identify the ‘main progenitor’ as the most massive identified in the merger tree. Identify the ‘main progenitor’ as the most massive identified in the merger tree. If this has mass less than half the mass of the parent halo, use the redshift of the previous snapshot as the formation redshift. If this has mass less than half the mass of the parent halo, use the redshift of the previous snapshot as the formation redshift. Otherwise, move to the next redshift slice, identifying the main progenitor there, and so on. Otherwise, move to the next redshift slice, identifying the main progenitor there, and so on. This corresponds with the formation time as defined in e.g. the theoretical studies of Lacey & Cole (1993). This corresponds with the formation time as defined in e.g. the theoretical studies of Lacey & Cole (1993).

The Marked Correlation Function Described in Sheth & Tormen (2004), this is a generalisation of the two-point correlation function. Described in Sheth & Tormen (2004), this is a generalisation of the two-point correlation function. For each halo, i, we define a ‘mark’ m i. The mark may be, for example, the formation redshift. Then the marked correlation function, M(r), is defined by For each halo, i, we define a ‘mark’ m i. The mark may be, for example, the formation redshift. Then the marked correlation function, M(r), is defined by where the sum is taken over all pairs of objects {i,j} with separation r=r ij but where the mean is taken over all objects in the sample. Therefore if M(r)>1 pairs of objects with separation r tend have a greater value of the mark than average. Therefore if M(r)>1 pairs of objects with separation r tend have a greater value of the mark than average. We do not need to choose a spatial scale to define environment – the marked correlation function picks this out for us. We do not need to choose a spatial scale to define environment – the marked correlation function picks this out for us.

Scaled formation redshift Instead of raw formation redshift, we use the quantity ω̃ defined in Lacey & Cole (1993) by: Instead of raw formation redshift, we use the quantity ω̃ defined in Lacey & Cole (1993) by: This precisely scales out the mass dependence of formation redshift in extended Press- Schechter theory for scale-free initial power spectra (and very nearly does otherwise). This precisely scales out the mass dependence of formation redshift in extended Press- Schechter theory for scale-free initial power spectra (and very nearly does otherwise).

Scaling tests

An example of a marked correlation function ‘Scrambled’ means we randomly permute the marks between the halos in the sample. ‘Scrambled’ means we randomly permute the marks between the halos in the sample. Scrambling within mass bins implies we only permute the marks between halos of similar mass. Scrambling within mass bins implies we only permute the marks between halos of similar mass. These processes would be equivalent if the scaled formation redshift precisely scales out the mass dependence. These processes would be equivalent if the scaled formation redshift precisely scales out the mass dependence. N p =68768 for M * halo

Different mass ranges

Other tests of environmental dependence Lemson & Kauffmann (1999) used as a measure of environment the overdensity within an annulus of Lemson & Kauffmann (1999) used as a measure of environment the overdensity within an annulus of 2 < r / h -1 Mpc < 5 centred on the halo. They found no signal, but the better statistics available from the Millennium Simulation do suggest a dependence on environment. They found no signal, but the better statistics available from the Millennium Simulation do suggest a dependence on environment.

Further work More experimentation with different mass ranges and comparison to traditional measures of environment. More experimentation with different mass ranges and comparison to traditional measures of environment. A marked cross-correlation function? A marked cross-correlation function? Alternative marks: for example, the number of progenitors above a certain mass or different definitions of formation time. Alternative marks: for example, the number of progenitors above a certain mass or different definitions of formation time. Effects of the above on clustering statistics, either of (sub)halos or semi-analytic galaxies. Effects of the above on clustering statistics, either of (sub)halos or semi-analytic galaxies. Further interpretation. Further interpretation. Different redshifts. Different redshifts.

Traditional tests of environment suggested by marked correlation function results

Further scaling tests Compare the marked correlation function with ω̃ as the mark with the function when we: Compare the marked correlation function with ω̃ as the mark with the function when we: Use raw formation redshifts; Use raw formation redshifts; Shuffle marks within small mass bins; Shuffle marks within small mass bins; Scale formation redshifts by dividing through by the mean formation redshift of halos of the same mass in the simulation. Scale formation redshifts by dividing through by the mean formation redshift of halos of the same mass in the simulation. Rank the scaled formation redshifts then force them to follow the analytic distribution. Rank the scaled formation redshifts then force them to follow the analytic distribution. The latter three make little difference to the final result. The latter three make little difference to the final result.

Lemson & Kauffmann figure using scaled formation redshift