1. The real discovery is not to discover new lands,
but to see the world with new eyes
Marcel Proust
(Ray Jayawardhana)
The use of precise molecular line spectroscopy in a search for me/mp variations
Alexander V. Lapinov,
G.Yu.Golubiatnikov
Inst. of Applied Physics of the Russian Academy of Sciences,
Nizhny Novgorod, Russia
Budapest

2. Dark clouds – unique physical laboratories
Very low temperature, Тk~10K and
density, n(H2)~104…105 cm-3
Radiation life time & critical density:
Transition Frequency τ(=A-1) n*(H2)
CO J=1– GHz days cm-3
NH3(1,1) GHz days cm-3
HC3N J=2–1 18 GHz days cm-3
HCN J=1– GHz hours 106 cm-3
Typical frequency of intermolecular
collisions:
n(H2)10-10 cm3/s~10-6…10-5 s-1 or
~ 1 collision per several days
B68, optics
J.F. Alves, C.J. Lada & E.A. Lada 2001 Nature 409, 159
How precisely interstellar =me/mp the same as terrestrial?
-1= (80), /=410-10
(if we increase μ by 3 then not only the life but even chemical elements are not possible!)

3. Precision of radio astronomical measurements:
(1999, IAU Symposium 197;
2003 ApJ 592, L95; 2006 SPIE )
Location
Pico Veleta, Sierra Nevada, 45km from Granada, Spain,
Long: 3°23’33.7”(W), Lat: 37°03’58.3”(N), Alt: 2920m
Date VLSR(km/s) FWHM(m/s)
20-Aug (92) (10)
14-Sep (101) (17)
(137)=0.5(10)kHz
ΔVTk=10K=124м/с, ΔVNT=139м/с

4. Radio astronomical spectroscopy of H15NC
Lapinov 2006 SPIE Proceedings 6580,
Radio astronomical spectroscopy of H15NC
H15NC J=1-0 frequency:
Laboratory measurements:
(26)MHz Lovas F.J., 2004
(Saykally et al. 1976, Ohio Symposium #31)
(40)MHz Pearson et al. 1976
(45)MHz Maki et al. 2001
Radio astronomical measurements:
(26)МГц (9 dark clouds)
(44)МГц (23 dark clouds)

5. Radio astronomical spectroscopy of H15NC
Lapinov 2006 SPIE Proceedings 6580,
Radio astronomical spectroscopy of H15NC
H15NC J=1-0 frequency:
Laboratory measurements:
(26)MHz Lovas F.J., 2004
(Saykally et al. 1976, Ohio Symposium #31)
(40)MHz Pearson et al. 1976
(45)MHz Maki et al. 2001
Radio astronomical measurements:
(26)МГц (9 dark clouds)
(44)МГц (23 dark clouds)
H.Bechtel (MIT) molecular jet measurements:
(14)MHz
(8)MHz (Global B, D, H fit)

6. Sketch of Lamb-dip spectrometer
BWO
P~1mTorr
Second
harmonics
detector
Lamb W.E. 1963
3rd Int.Conf.Quant.Electr., Paris
Lamb W.E.1964
Phys.Rev.134,1429
MacFarlane R.A., Bennett W.R.,
& Lamb W.E. 1963
Appl. Phys. Lett. 2, 189
Dryagin Yu.A. 1970
Radiophys. & Quant. Electr. 13, 107
Line center uncertainty (Landman et al ApJ 261, 732):

7. Near by sub-Doppler spectrometer at Kiel University

8. Typical examples of Lamb-dip measurements
2005 J.Molec.Spectrosc. 234, 190
all ν0 <500 GHz were measured at ≤ 1 kHz accuracy
- one of the best secondary standard for lab spectroscopy

9. Are rest molecular frequencies everywhere
the same? How universal is our Universe in different parts? How small difference can we reveal from spectral measurements of different type molecular transitions?

10. inv /inv = 4.5 / N H H H H H H N
double-well potential of the inversion vibrational mode of NH3 N
U(x) H H H H H N N H H H H
10-4 eV H
  1.3 cm H x H N
E=23.3 K
inv /inv = 4.5 /
NH3 J,K=1,1 inv= (48)MHz
18 hf components, σV=0.61m/s
S.G. Kukolich, 1967, Phys.Rev. 156, 83
E=22.1 K

11. HC3N hyperfine spectrum rot /rot = 1.0 /
E=2.6 K
J F – J F Frequency(MHz) shift(km/s)
σV=2.8m/s
2 1 – (17) (9)
2 1 – (17) (7)
2 3 – (17) (2)
2 2 – (17) (0)
2 1 – (17) (4)
2 2 – (17) (6)
E=1.3 K
HC3N J=1–0 data:
de Zafra R.L., 1971 ApJ 170, 165
eQqN, CN data:
R.L. DeLeon and J.S. Muenter, 1985,
J.Chem.Phys. 82, 1702
E=0 K

12. Examples of measured HCN line shapes at different spectral resolution
(IRAM Newsletters 54, 2002 | Source selection – Fuller & Myers 1993 ApJ 418, 273: NH3, HC3N)

13. NH3(1,1) & HC3N(2-1) in dark cloud L1512
V(HC3N) – V(NH3) = 26.5  1.2 m/s
Searching for chameleon-like scalar fields with the ammonia method 2010, Astron.Astrophys., v.512, A44 & Astron.Astrophys., v.524, A32 S.A.Levshakov, P.Molaro, A.V.Lapinov, D.Reimers, C.Henkel, T.Sakai S.A.Levshakov, A.V.Lapinov, C.Henkel, P.Molaro, D.Reimers, M.G.Kozlov, I.I.Agafonova 13

14. NH3(1,1) & HC3N(2-1) in dark cloud L1498
V(HC3N) – V(NH3) = 27.3  1.6 m/s
V(HC3N) – V(NH3) = 24.7  1.5 m/s

15. Conclusions about me/mp based on NH3 and HC3N measurements
Performing Hannover FTMS and N.Novgorod Lamb-dip data we’ve improved by an order the HC3N rest frequencies in comparison with CDMS. By more than an order we’ve improved frequencies for H13CCCN, HC13CCN, HCC13CN and HCCC15N. Final relative accuracy for all ground state rotational transitions below 500 GHz is ≤ 10-9.
Taking into account NRO-45m measurements in HC3N J=5–4 and NH3(1,1) towards L1498 with Vrot–Vinv=–0.1±2.8 m/s, as well as recent Medicina-32m data in HC3N J=2–1 and NH3(1,1) towards L1498 and L1512 with Vrot–Vinv=–0.9±3.1 m/s и +0.4±3.1 m/s, it’s possible to conclude that for|ΔV|<3 m/s we have |Δµ/µ|<3·10-9, what is three orders more precise in comparison with cosmological estimates of µ variation.
What about our 2010a&b results - sometimes “high precision” is not equal to “high accuracy”:

16. Sub-Doppler spectrometer at the Institute of Applied Physics,
N.Novgorod

17. Accuracy of OCS sub-Doppler spectroscopy

18. Examples of HCCCN Lamb-dip measurements
HC3N J=8–7: νcal= (7) MHz, σV=0.31m/s
HC3N J=11–10: νcal= (1) MHz, σV=0.30m/s
νobs (MHz)
O – C (kHz)
Reference
(08)
(10)
0.2
-0.1
CDMS fit
This work
νobs (MHz)
O – C (kHz)
Reference
(11)
(10)
0.2
CDMS fit
This work

19. Examples of HCCCN Lamb-dip measurements

20. Torsion-rotation spectroscopy of CH3OH
Paul Jansen et al Phys.Rev.A 84,
Sensitivity of transitions ... to me/mp
Li-Hong Xu et al J.Mol.Spectr. 251, 305
Torsion-rotation global analysis...

21. Sketch of energy level splitting in CH3OH-E vt=021

22. Examples of CH3OH-E vt=0 measurements

23. 2323 V96.7 ГГц /c = -1.0 / V108.9 ГГц /c = -4.5 /
A search for me/mp variations based on laboratory
and radio astronomical measurements of CH3OH (2014 A&A 569, A27)
J,K–J',K'
Frequency (MHz) 
VLSR (km/s)
A 2,0–1,0
(7) 1
7.1955(13)
E 2,-1–1,-1
(7)
7.1983(11)
E 2,0–1,0
(7)
7.2043(51)
E 0,0–1,-1
(6)
4.5
7.1803(30)
V96.7 ГГц /c = -1.0 /
V108.9 ГГц /c = -4.5 /
/ =0.3(V96.7 ГГц -V108.9 ГГц )/c=(1.6+/-0.3)10-8
<V96.7 ГГц> = (13)km/s 23

24. L1544 CH3OH and OCS measurements (2014 A&A 569, A27)

25. L1544 line intensity versus line width
in CH3OH and OCS (2014 A&A 569, A27)

26. Study of IRDC (2014 ApJ 780, 85)

27. Doppler tomography of IRDC028.34-6 (2014 ApJ 780, 85)27