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Strong Limits on a Variable Strong Limits on a Variable Proton to Electron Mass Ratio (Proton to Electron Mass Ratio ()) from Ammonia Inversion Linesfrom Ammonia Inversion Lines
C. Henkel (MPIfR, Bonn)
NH3
Ratio of strong to weak scale
Common Method Compare frequencies of vibrational and rotational molecular transitions
H2 in Quasars(Vibro-Rotational Absorption Lines)
Extragalactic Ammonia (NH3)
First polyatomic molecule detected in interstellar space (1968)
• Large number of transitions within a limited frequency range (inversion lines)• Wide range of excitation conditions• Widespread spatial distribution• Hyperfine structure allows us to directly determine optical depths• Densities and gas kinetic temperatures can be derived
Frye, Welch, Broadhurst 1997, ApJ 478, L25
Lens at z = 0.88582HI absorption also at z = 0.19(zblazar = 2.507)Dim r ~ 0.5” Einstein ring
PKS 1830-211:
12CO
13CO
= mp/me
NH3 inversion versus rotational lines:
3.46 (Δ/) = (zinv – zrot) / (1 + z) = ΔV/c
(Early discussions with J. Chengalur in Epping)
(Flambaum & Kozlov 2007, Phys. Rev. Let. 95, 240801)
B0218+357
Δ/ < 2.7 10-6 (3σ limit)(Δ/Δt)/ < 4.5 10 -16 yr-1 (3σ limit)
(Murphy, Flambaum, S. Muller et al. 2008, Sci 320, 1611)
Strength: A very thorough analysis
Caveats: Few NH3 and few rotational lines (chemistry?) Different frequencies (cm versus mm-waves) Optically thin versus optically thick lines
Redshifted frequencies between 12.56 and 15.17 GHz
Background continuum between 6.5 and 8 Jy
NH3
PKS1830-211
τapparent: 0.0008 – 0.03 (NH3) 0.35 for prominent (mm-wave lines) (Wiklind & Combes 1996, 1998) and with 0.1 at dm-wavelengths (Chengalur et al. 1999).
NH3
PKS1830-211
9.00.1, 8.60.5
7.40.2, 10.50.4
8.60.1
8.40.2, 9.10.7
8.20.3, 8.70.5
8.10.2, 8.50.6
10.90.4
8.50.6
8.80.7
10.22.0
PKS1830-211
APEX
Ground rotational transitionof NH3
Δ/ 5.7 10-6
(3σ limit)
Strength: One moleculeCaveats: 15 GHz versus 300 GHz One rotational line Limited S/N ratio
Menten et al.2008, A&A492, 725
Effelsb
ergRotational spectra of othermolecules at nearby frequencies
SO J = 1−0
SO J = 2−1
C34S J = 1−0
H13CO+ J = 1−0
H13CN J = 1−0
HN13C J = 1−0
PKS1830−211HC3N
3.8 K < TCMB < 7.2 K
Expected value: 5.14 K
SiO (6.8 0.3) KC34S (7.2 0.4) KH13CO+ (3.8 0.3) KH13CN (4.8 0.5) K
Unweighted Mean: (5.65 0.81) K
[TCMB = 2.73 (1 + z)]
<V>NH3 = 8.81 0.23 km/s <V>HC3N = 8.73 0.43 km/s<V>others = 9.07 0.38 km/s
<V>NH3,low = 8.82 0.45 km/s<V>NH3,high = 8.94 0.27 km/s
NH3 + HC3N:Δ/ < 1.4 10-6 (3σ, NH3, HC3N)
Also including the other lines Δ/ < 1.0 10-6
Strength: Many molecular lines of both kinds Similar frequencies Optical depths << 1 No apparent velocity shift with excitation Small time interval between the measurements
Caveats: The excitation of the inversion lines is higher than those of the rotational lines A thorough multicomponent analysis is still missing
Preliminary Results:
Molaro, Levshakov & Kozlov (astro-ph/0907.1192)Levshakov, Molaro, & Kozlov (astro-ph/0808.0583)
NH3, C2H, HC3N, N2H+: 35 – 53 m/s !!! Δ/ 4 10-8 !!!
Accuracy to be achieved: Δ/ 10-8 !!! 10 m/s
Chameleon Fields
Quintessential Fieldvarying in time and space?
Coupling with matter could change fundamentalquantities locally.