How to Measure Evolution in the Fundamental Constants of Physics with Large Telescopes Chris Churchill (Penn State) …and sneak in astronomical observations on the evolution of galaxies and the intergalactic medium

Executive Summary 1.Motivations 2.CMB/BBN 3.And the Winner is…QALs 4.Fine Structure Constant 5.Electron-Proton Mass 6.Bread and Butter Astronomy 7.Concluding Remarks

Classes of Theories Attempts to solve some cosmological problems… Multi-dimensional and String Theories Scalar Theories (varying electron charge) Varying Speed of Light Theories Unification of quantum gravity with other forces… Couples E+M to cosmological mass density… Modified Bekenstein theories…

Fundamental “Constants” that are ripe for investigation…  = e 2 /hc 2.x =  2 g p /  3.y =  2 g p  = m p /m e  z  o   x  x  z opt – z 21 )/(1+z   y  y  z mol – z 21 )/(1+z  z i = z o + bK i b = (1 + z o ) 

Last scattering vs. zCMB spectrum vs. l CMB Behavior and Constraints Smaller  delays epoch of last scattering and results in first peak at larger scales (smaller l) and suppressed second peak due to larger baryon to photon density ratio. Solid (  =0); Dashed (  =-0.05); dotted (  =+0.05) (Battye etal 2000)

BBN Behavior and Constraints D, 3 He, 4 He, 7 Li abundances depend upon baryon fraction,  b. Changing  changes  b by changing p-n mass difference and Coulomb barrier. Avelino etal claim no statistical significance for a changed  from neither the CMB nor BBN data. They refute the “cosmic concordance” results of Battye etal, who claim that  =-0.05 is favored by CMB data. (Avelino etal 2001)

QSO absorption line methods can sample huge time span QSO Absorption Lines (history) Savedoff (1965) used doublet separations of emission lines from galaxies to search for  evolution (first cosmological setting) Bahcall, Sargent & Schmidt (1967) used alkali-doublet (AD) separations seen in absorption in QSO spectra.

 z =  0 + q 1 x + q 2 y  z = redshifted wave number x = (  z /  0 ) 2 - 1y = (  z /  0 )  0 = rest-frame wave number q 1, q 2 = relativistic correction coefficients for Z and e - configuration Mg II 2803 Mg II 2796 Fe II 2600 Fe II 2586 Fe II 2382 Fe II 2374 Fe II 2344 The Many-Multiplet Method

SIMULATIONS…. HIRES/Keck resolution and pixel sampling rate, infinite signal to noise Black lines are unshifted data. Red lines are shifted for  Fe II shifts to blue by ~10(1+   times that of Mg II, though each Fe II has a unique shift magnitude. Cr II shifts to red compared to Si II and Zn II shifts blue as compared to Si II, also with different shift magnitudes Relative Shifts of Large Shifters for  =+10 -4

Webb et al Results 1.49 absorption cloud systems over redshifts 0.5–3.5 toward 28 QSOs compared to lab wavelengths for many transitions 2.2 different data sets; low-z (Mg II, Mg I, Fe II ) high-z (Si II, Cr II, Zn II, Ni II, Al II, Al III ) 3.Find  = (–0.72±0.18) × (4.1  ) (statistical) 4.Most important systematic errors are atmospheric dispersion (differential stretching of spectra) and isotopic abundance evolution (Mg & Si; slight shifting in transition wavelengths) 5.Correction for systematic errors yields stronger  evolution

 = (–0.72±0.18) × (4.1  ) (statistical) (Webb etal 2001)

Soon to the Press Preliminary Findings… Now have a grand total of 138 systems due to adding the HIRES data of Sargent et al. Find  = (–0.65±0.11) × (6  ) (statistical)

The Future Same and new systems observed with different instruments and reduced/analyzed by different software and people. Build UVES/VLT and HRS/HET data base in order to reproduce the HIRES/Keck results Raid STIS/HST archive (already done) to perform the study at z=0 (in Galactic HVCs).

(Murphy etal 2001) Measuring y=g p  2  and y=g p  2 Evolution is Problematic The line of sight probed by 21-cm may not be the same probed by the QSO! Carilli etal (2001) attempt to minimize this using VLBI for 21 cm.

(Potekhin etal 1998) Measuring  =m p /m e is a simple matter of finding damped Ly-alpha systems with hydrogen molecules! Not so easy, only five known to date. Combining 2 QSOs, Ivanchik etal (2002) find  = (5.7 +/- 3.8) x At z=3. Searching with Sara Ellison (ESO) and Max Pettini (IoA) using CORALS

(Potekhin etal 1998) Vibrational and Rotational states of H 2 have different  dependence! This is parameterized using sensitivity coefficients, K. K i = dln( i )/dln(  Simple linear regression z i = z o + bK i b = (1 + z o )  Though Potekhin etal (1998) and Ivanchik etal (2002) have placed excellent limits on , a zero redshift calibration would be useful to check that the sensitivity coefficients are not systematically influencing the results.

(Martini etal 2000) The photodissociation regions of Galactic reflection nebulae show strong H 2 emissions lines. These emission lines can be used to place z=0 constraints on . This has never been tried, but is in principle straight forward and favorable in that reflection nebulae are abundant (good stats). The phoenix on Gemini-S is ideally suited for this… R=50,000 and a signal to noise of 30/pixel on a K=12 object in 1 hour (in the continuum)!!

Cooling Flow Galaxies exhibit strong H 2 emission lines! Seven CF galaxies known to date with H 2 emission. Redshifts are in the range 0.05 to Kinematics of gas (~500 km/s) may be a problem, but experience with all gas is that the lower the ionization level, the smaller the physical size and the narrower the profiles. Thus, it is expected that these features will break up into multiple narrow velocity components. Exploring this with Alexander Delgarno (CfA) (Falcke etal 1998)

And now for something completely different…

A uniform and high quality library of QSO Spectra can be fully exploited to learn many fundamental properties of the high redshift universe. Kinematic, chemical, and ionization conditions of galactic gas and of the Lyman alpha forest. Evolution in number per unit redshift (number density X cross section) Detailed photo-ionization modeling yields chemical evolution and size constraints Directly probe inter-galactic and galactic conditions to highest redshifts Mg II absorbers are ideal - associated with galaxies and with Lyman alpha forest clouds… charts first generation of stars in all environments…

We require high resolution spectra… (Churchill 1997)

(Churchill etal 2001)

(Churchill et al 1999; Rigby etal 2002) Predicted for a decade to not exist… these spectra were peppered with “weak” systems….

Summary of Weak Mg II Systems

(Churchill & Vogt 2001) The kinematics of the “Strong” Systems

Establishing Direct Connection with Galaxies Note weak systems are not identified with galaxies Strong systems typically within 40 kpc of QSO line of sight A pilot project in which the stellar rotation curves of five z=1 edge- on spiral galaxies were measured with LRIS/Keck revealed that the absorption traces the disk kinematics far out into the halo (Steidel etal 2002). We are currently extending this project to 30 galaxies with HST imaging, high resolution absorption line data, and stellar rotation curves (spirals) or velocity dispersions (ellipticals).

(Churchill 2001)

Interpreting Complex Absorption Line Profiles Each absorption line arises from an individual cloud with some line-of-sight velocity. Complex profiles are blends of many clouds that are distributed in some geometric/kinematic arrangement(s) in and/or near normal bright galaxies. Simple models of galactic disk geometry and kinematics and of “halo” geometry and kinematics are statistically consistent with the observed complex profiles. (Charlton & Churchill 1996, 1998; Churchill & Vogt 2001)

State of the Mg II Union (Churchill & Charlton 2002)

HRS (z = ) and JCAM (z = ) on HET (Churchill & Charlton 2002)

Simulated JCAM/HET Spectrum

JCAM/HET Commissioning Data R=11,000 ~ 28 km/s J=12  =2500 sec ~1.15  m

The Future 1.Continue  work in collaboration with UVES/VLT and bring in HRS/HET. Long term (10 years)- independent work at R=120,000 with HRS! 2.Independently measure  in Galactic HVCs using STIS/HST archival data 3.Measure  in Galactic reflection nebulae (need pilot) and eventually in cooling flow galaxies to z=0.2. This is H 2 emission line work. Search for high-z DLAs with H 2 molecules and measure  in absorption to z= Extend studies of Mg II kinematics, chemical, and ionization conditions to z~4 with UVES/HRS/JCAM 5.Continue establishing kinematic connections with Mg II absorption and stellar kinematics; establish nature of “weak” systems.

Varying Electron Charge Theories   Variation occurs over matter dominated epoch of the universe. (Barrow etal 2001)

Varying Speed of Light Theories Motivation is to solve the “flatness” and “horizon” problems of cosmology generated by inflation theory (Barrow 1999; Moffat 2001). Theory allows variation in  to be ~10 -5 H 0 at redshift z=1. Evolution is proportional to ratio of radiation to matter density.