Why are they interesting? What can we learn about how and when the elements were created, what processes injected the metals into the IGM

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1 1 Chemical Abundances in Clustes Why ae they inteesting? What can we lean about how and when the elements wee ceated, what pocesses injected the metals into the IGM Which stas poduce the metals What is the chemical abundance Manta fo the day Innocent light-minded men,who think that astonomy can be leant by looking at the stas without knowledge of mathematics will, in the next life, be bids :Plato, Timaeus Chemical Abundances In Clustes Remembe: 80% of the bayons ae in the gas We detect line emission in the x-ay band fom atomic tansitions in H,He-like ions Clustes ae oughly big closed boxes Use these data to measue the chemical abundance of the gas The stength of the lines depends on Atomic physics # of ions of a given species Tempeatue The numbe of potons (H atoms) depends on the stength of the bemmstahlung continuum The atio of the numbe of ions to the numbe of potons is the abundance with espect to hydogen 3 The Cluste gas is a good place to measue abundances Most of the bayons and metals ae in the hot gas Well undestood emission mechanism No adiative tansfe difficulties Dust not a poblem The deep potential well captues an integated ecod of all the metals poduced Tue aveages Simple physics (H and He-like lines) Wide ange of elements Diect measuement of electon tempeatue fom continuum Can measue Fe to z~1 and Si to z~0.4 We can thus obtain a tue measue of the metal fomation mechanism and its evolution 4 Whee do the Bayons Go? Most of the bayons in the univese (>80%) do not live in galaxies (Fukugita and Peebles 007)! stas h = / ! total (Bayon)h =0.014 In a simulation of the fomation of stuctue only a small faction of the bayons (light blue) end up as stas Numeical simulation of whee the bayons live (today)paticles in ed and geen ae in clustes- ed close to cente Tuquoise is sta foming gas

2 5 Oigin of 'Metals' Metal poduction is dominated fo (0 Ni) by supenova. Type II (coe collapse) poduce most of the O and Type I poduce most of the Fe. The faction of othe elements (e.g. Si,S) that ae poduced by the SN depend on the IMF and the (pooly undestood) yields of the SN. If the obseved cluste galaxies ae the souce of the metals and 'standad' SN ates and IMF ae assumed poduces 1/3 of the the obseved metals 7 Type II- massive stas; shot lifetime, lots of light Type II (coe collapse) poduce most of the O and Type I poduce most of the Fe. This is a diect indication that galaxies ae 'open' systems 6 Type I - white dwafs which explode due to accetion- old population, little optical light, long life (not well undestood) The faction of othe elements (e.g. Si,S) that ae poduced by the coe collapse SN depend on the IMF and the (pooly undestood) yields of the SN. Histoy of Science Comment It is athe supising to ealize not only is most of the mateial in the univese dak and non-bayonic, but that most of the bayons in the univese do not shine in optical light. The anthopomophic pictue that the univese can be best studied with the light visible to ou own eyes is not only seiously in eo, it dives science in the wong diections. Thee is only little o weak evidence that the stella populations in cluste galaxies ae diffeent fom those in the field (othe than the fact that clustes have a much lage pecentage of elliptical and S0 galaxies) Which Stas Make Which Metals Since most of the metals ae in the gas >70% of the metals geneated in galaxies has to be 'lost' fom galaxies (whee the stas live) to the ICM 8 Supenova Yields The amount of each element depends on the type of SN, the IMF and the code used to do the pediction. Fo Saltpete IMF and a system that holds onto all of its metals the elative yield of each element pe unit mass Type IType II Oxygen Fe

3 The study of the metal 9 enichment of the intacluste medium (ICM) epesents a diect means to econstuct the past histoy of sta fomation the slope of the initial mass function (IMF) the elative numbe of type I and II SN the ole of feedback pocesses the metallicity of the gas which accetes into clustes as the univese evolves Bogani et al 009- Model of when Fe is poduced in a galaxy fomed at z=0 fom type I and coe collapse (type II ) SN (massive stas type II type I when ae the elements poduced and by which types of SN 10 Effect of AGN Feedback on Metallicity The AGN in the galaxy will tend to 'push' gas out of the galaxy, depositing metals and enegy in the ICM Thus the metallicity of the galaxies and that of the ICM will be effected as well as the distibution of metals Theoetical calculation of the effects of AGN feedback -Sijack et al 007 Geen solid metallicity in galaxies vs adius dashed-same with feedback Blue gas metallicity with and without feedback 11 Mass-to-Light Ratio: MLR Metals ae synthesized in stas (galaxies): Compae the mass of metals M metal, < R ( in units of M! ) with luminosity of stas in some band to get the (element) mass to light atio (simila to mass to light atio) Fe mass / B-band Luminosity MLR = Oxygen Mass-to-Light Ratio: OMLR Magnesium Mass-to-Light Ratio: MMLR Ion Mass-to-Light Ratio: IMLR M metal, < R L B o K, < R M! L! 1 One of the majo issues is when did clustes fom and what does that mean? CDM simulations indicate when the mass concentations fomed- but wee they populated with galaxies and gas? A sepaate issue is the age of the stella population The oldest aveage age fo a stella population is found in the most massive galaxies in clustes 006ARA&A Renzini Stella Population Diagnostics of Elliptical Galaxy Fomation How Old ae the Galaxies Van Dokkum and van de Mael 007

4 13 Dependence on IMF 14 Physics of Line and Continuum Emission Two of the most used intial mass functions ae those of Koupa and Salpete. At late times (today) on can see that the 'Ion mass to light atio' (IMLR) diffes by a facto of ove fo the same amount of Fe poduced Density 10 _5 10 _1 cm _3 cluste outskits to the densest egions 3 fundamental emission pocesses contibute to the adiation: fee fee o bemsstahlung adiation fee bound o ecombination bound bound o deexcitation The fist two pocesses give ise to continuum adiation and the latte to line adiation. low density of the plasma ensues that all the ions excited by collisions have sufficient time fo adiative deexcitation befoe a second deexciting collision occus. contay to laboatoy plasmas, all fobidden tansitions actually happen in the ICM plasma. all exciting, ecombining, and bemsstahlung causing collisions lead to the adiation of a photon, which is efeed to as the thin plasma adiation limit (o coonal limit, as simila conditions pevail in the sola coona). The modeling of the themal plasma spectum is a book keeping execise. The collision ates ae in geneal a function of tempeatue)and the outcome is diectly popotional to the electon density 15 Abundances Clustes of galaxies deep gavitational potential wells keep all the metals poduced by the stella populations of the membe galaxies within the cluste. The dominant faction of these metals eside within the hot ICM. The chemical abundances measued in the inta-cluste plasma thus povide us with a fossil ecod of the integal yield of all the diffeent stas (eleasing metals in supenova explosions and winds) that have left thei specific abundance pattens in the gas pio and duing cluste evolution. 16 Spectal model

5 17 Viialized systems- Clustes, Goups and Big galaxies XMM Gating Results- J. Peteson et al These data have less systematic eos than the CCD data but lowe S/N 18 Aveage Cluste Metallicity Pofile Rises in cente to ~0.5 sola Asymptotes at > to 0. sola No dop to lagest adii ( ) measued <Fe>=0.33/-0.08 but eal vaiation fom cluste to cluste - full ange is a facto of at 500 Abundance mass weighted Eo bas-eo in the mean Lines- vaiance of sample / 500 Abundance mass weighted Cluste metallicity at 500 vs kt kt 19 Cluste Metallicity The abundances ae not unifom in the cluste but can be highe in the centeat lage adius tend towas ~1/3 sola Most of the metals ae in the oute egions (follow the bayonic mass if the abundances ae constant) Tempeatue Abundance 0 Relative Abundance of Diffeent Elements The elative abundance of diffeent elements is elated to the pocesses that poduce them Fe and Ni ae mostly made (we think) in type I supenova (the explosion of a white dwaf)* Oxygen and Neon ae made mostly in a type II SN- the explosion of a massive sta The elative and absolute numbe of SN is elated to the distibution of the masses of the stas and othe inteesting things de Plaa et al. (007) *we will discuss the ceation of elements in SN late in the class when we discuss supenova and SN emnants

6 1 Fitting esults O AWM7 (Ne) Mg W7 model S Si Fe Ratio of the numbe of each type of SN NSNe II / NSNe Ia = 4.0 ± 1. Abundance Pattens in Clustes In pinciple one could detemine the patten of type I and type II SN esponsible fo ceating the elements- howeve the Si and S atios disagee with simple models (also O/Fe values) Pue Type Ia Pue Type II " ~75% of Fe, ~40% of Si and S fom SNe Ia Pue Type Ia Sato et al Si/Fe and S/Fe soted by Fe abundance Finoguenov et al -shaded band is MW stas Ne is excluded in the fits. SNe II SNe Ia W7 Gas mass M! SNe II/Ia atio Is thee a Unifom Abundance Patten?? Numbes and Ratio of SNe Ia & II 4 Numbes of SNe Ia & II 3 W7 model 3.5 Gas mass M! " Numbes of SNe Ia & II the gas mass " SNe II/Ia Ratio: ~3.5 (W7 and WDD), ~.5 (WDD1) cf. Clustes (XMM ; de Plaa et al. 007): ~3.5 Ou Galaxy (Tsujimoto et al. 1995): ~6.7 LMC & SMC (Tsujimoto et al. 1995): 3.3 5

7 5 As noted in Gibson et al 1997 the elemental abundance atios aveaged ove the cluste do not agee with any simple atio of type Is to type IIs- howeve it is clea that ove 90% of the O,Ne,Mg oiginated in type IIs 6 Abundance Pofiles X-ay CCD data can deive easonable abundance pofiles fo the most abundant elements (O, Si, Fe) The new XMM oxygen abundances futhe stengthen this conclusion - some of the difficulties may be caused by diffeential abundance gadients of diffeent elements Compaison of aveage cluste O,Si,S,Ne abundances with SN theoy aveage value M Fe, SNIa /M Fe total R/R Metallicity Evolution Thee is weak evidence fo cluste metallicity evolutionwhen wee the metals poduced Most of the metals wee in place at z~0.5 and maybe at z~1 This indicates that most sta fomation occued in clustes at high edshift, consistent with estimates of the ages of the galaxies z<0.4 z>0.4 Andeson et al edshift Ehlet and Ulme 009 Metals 8 ae synthesized in stas (galaxies): Mass-to-Light Ratio: MLR Compae the mass of metals M metal, < R ( in units of M! ) with B-band luminosity of stas (simila to mass to light atio) L B, < R ( in units of L! ) Fe mass / B-band Luminosity Makishima et al. (001) MLR = M metal, < R L B o K, < R Tempeatue (kev) mass of system Oxygen Mass-to-Light Ratio: OMLR Magnesium Mass-to-Light Ratio: MMLR Ion Mass-to-Light Ratio: IMLR M! L!

8 9 Ion Mass to Light Ratioband "a backgound 30 Metal enichment OMLR & pocess MMLRin the ICM - shows facto of seveal vaiation IMLR K-band fo optical light OMLR / 180 / 180 / How Much Metals Should be Poduced? 3 Non-Unifom Distibution of Metals The pesent day mass in stas (infeed fom thei light, age and IMF) should tell us how many type I and II supenova have occued and thus the total mass of metals poduced ove all time e.g, fo any given IMF, one can compute the coesponding ates of SNe II and SNe Ia and the ate of poduction of ion MFe tot (t) (Figs. 1a and 1b) o of any othe element. Fo the same IMF, the coesponding SSP (simple stella population) deived fom stella isochones gives the luminosity evolution L B (t) Salpete IMF can epoduce the obseved ion enichment if ~80% of the ion synthesized is shed into the ICM. Change in light of galaxy as a function of time Fe Abundance in M87- all is not so simple! In addition to adial gadients in some clustes thee is tue spatial vaiation Pesumably this is due to the effects of meges

9 Compaison of dak matte and x-ay cluste and goup distibution 33 evey bound system visible in the numeical simulation is detected in the x-ay band - bight egions ae massive clustes, dimme egions goups, 34 Summay of Some of the Impotant Equations Dak matte simulation X-ay emission in simulation 35 Sound Cossing Time 36 Cluste Potentials P 5 P cs = ) = ( 3 ( c s 1500 & T ' # $ 8! % 10 K " 1/ & T t # s ( ' $ 8! % 10 K " km/s ) 1/ & D # $! y % Mpc" 1s 1dm( ) =, - / 1 * s. s c ) / ( 5 fo clustes, vi vi ( Mpc, 3 s s M ( ) = 401 s ( 400 kpc s & # $ ln(1 ) '! % s s " "

10 37 " P =! $ "# Hydostatic Equilibium 1 dp d# GM ( ) =! =! spheical $ d d If we wish to use the positions and velocities of the galaxies because they have 'obits' they cannot be teated as a fluid and one has to use a diffeent equation. 38 Hydostatic Equilibium density and potential ae elated by Poisson s equation!!$ = 4'"G and combining this with the equation of hydostatic equil!. (1/"!P)=-!!$ =-4'G" assuming spheically symmetic system 1/ d/d ( /" dp/d)=-4'"g" which can be expessed as GM()=kT g ()/µgm p ) (dlnt/ddln" g /d) Dynamical data: use the collisionless Boltzman eq (conceptionally identical to the use of gas tempeatue to measue mass, but stas have obits while gas is isotopic) the, # and $ components of the velocity dispesion %, the logaithmic deivative of the stella density &, and the cicula velocity V 39 Mean Fee Path fo Collisions/ Enegy ( e ( 3 ' T $ % 8 " & 10 K # ' n $ %! 3! 3 " & 10 cm #! 1 kpc $ p " $ e = 8 3/ 3 ( kt ) 4 # n e ln! At T>3x10 7 K the majo fom of enegy emission is themal bemmstahlung continuum )~ 3x10-7 T 1/ n egs/cm 3 /sec- how long does it take a pacel of gas to lose its enegy? *~nkt/) 8.5x10 10 ys(n/10,3 ),1 T 8 1/ At lowe tempeatues line emission is impotant e 40 Beta Model (Cavaliee & Fusco-Femiano 1976) d ln! gal d" ) kt # gal = * = ' d d ( µ m -gal,0 -gal ( ) = 3/ &, ) # $ 1 * '! $ % c (!" p & d ln! $ % d

11 41 Beta Model (cont.) 1/ 3 / ) ( but teat as fitting paamete 1 ) (! " " # $ % % & ' ( ) *, -. / " " # $ % % & ' ( ) *, - = µ 0 c X gal p c I kt m 4 Beta Model (cont.) - "..