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Exploring Molecular Variations in Dark Clouds

This study focuses on the use of precise molecular line spectroscopy to search for molecular variations in dark clouds, with the aim of understanding the universality of molecular frequencies in different parts of the universe.

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Exploring Molecular Variations in Dark Clouds

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  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 13.10.2015 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: TransitionFrequencyτ(=A-1)n*(H2) CO J=1–0 115 GHz 162 days 103 cm-3 NH3(1,1) 24 GHz 69 days 103 cm-3 HC3NJ=2–1 18 GHz30 days 103 cm-3 HCN J=1–0 87 GHz 12 hours 106 cm-3 Typical frequency of intermolecular collisions: n(H2)10-10cm3/s~10-6…10-5 s-1 or ~ 1collision per several days B68, optics J.F. Alves, C.J. Lada & E.A. Lada2001 Nature 409, 159 How precisely interstellar =me/mp the same as terrestrial? • -1=1836.15267247(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 658001) Location Pico Veleta, Sierra Nevada, 45km from Granada, Spain, Long: 3°23’33.7”(W), Lat: 37°03’58.3”(N), Alt: 2920m

  4. Lapinov 2006 SPIE Proceedings 6580, 6858001 Radio astronomical spectroscopy ofH15NC H15NCJ=1-0 frequency: Laboratory measurements: 88 865.692(26)MHz Lovas F.J., 2004 (Saykally et al. 1976, Ohio Symposium #31) 88 865.715(40)MHz Pearson et al. 1976 88 865.709(45)MHz Maki et al. 2001 Radio astronomical measurements: 88 865.6964(26)МГц (9 darkclouds) 88 865.6954(44)МГц (23 dark clouds)

  5. Lapinov 2006 SPIE Proceedings 6580, 6858001 Radio astronomical spectroscopy ofH15NC H15NCJ=1-0 frequency: Laboratory measurements: 88 865.692(26)MHz Lovas F.J., 2004 (Saykally et al. 1976, Ohio Symposium #31) 88 865.715(40)MHz Pearson et al. 1976 88 865.709(45)MHz Maki et al. 2001 Radio astronomical measurements: 88 865.6964(26)МГц (9 darkclouds) 88 865.6954(44)МГц (23 dark clouds) H.Bechtel (MIT) molecular jet measurements: 88 865.6966(14)MHz 88 865.6958(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 DryaginYu.A. 1970 Radiophys. & Quant. Electr. 13, 107 Line center uncertainty (Landman et al. 1982 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 GHzwere 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. double-well potential of the inversion vibrational mode of NH3 N U(x) H H H H N H N H H H H 10-4 eV H  1.3 cm H x H N E=23.3K inv /inv = 4.5 / NH3 J,K=1,1 inv=23694.495487(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 – 1 1 18198.37461(17) -35.54874(9) 2 1 – 1 2 18197.07688(17) -14.16804(7) 2 3 – 1 2 18196.31047(17) -1.54098(2) 2 2 – 1 1 18196.21694(17) 0.00000(0) 2 1 – 1 0 18195.13615(17) 17.80653(4) 2 2 – 1 2 18194.91922(17) 21.38070(6) E=1.3 K HC3N J=1–0 data: de Zafra R.L., 1971 ApJ 170, 165 eQqN, CN data: R.L.DeLeon andJ.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 method2010, Astron.Astrophys., v.512, A44 & Astron.Astrophys., v.524, A32S.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

  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 onNH3 andHC3N 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 andNH3(1,1) towards L1498 with Vrot–Vinv=–0.1±2.8m/s, as well as recent Medicina-32m data in HC3N J=2–1 and NH3(1,1) towardsL1498 andL1512 with Vrot–Vinv=–0.9±3.1m/s и +0.4±3.1m/s, it’s possible to conclude that for|ΔV|<3 m/swe 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= 72783.82268(7) MHz, σV=0.31m/s HC3N J=11–10:νcal= 100076.3913(1) MHz, σV=0.30m/s

  19. Examples of HCCCN Lamb-dip measurements

  20. Torsion-rotation spectroscopy of CH3OH Paul Jansen et al. 2011Phys.Rev.A 84, 062505 Sensitivity of transitions ... to me/mp Li-Hong Xu et al. 2008J.Mol.Spectr. 251, 305 Torsion-rotation global analysis...

  21. Sketch of energy level splitting in CH3OH-E vt=0

  22. Examples of CH3OH-E vt=0 measurements

  23. A search for me/mp variations based on laboratory and radio astronomical measurements of CH3OH (2014 A&A 569, A27) 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> = 7.1973(13)km/s

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

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

  26. Study of IRDC028.34-6 (2014 ApJ 780, 85)

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

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