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The CDMS View on Molecular Data Needs of Herschel , SOFIA, and ALMA

Holger S. P. Müller , C. P. Endres, J. Stutzki, S. Schlemmer. The CDMS View on Molecular Data Needs of Herschel , SOFIA, and ALMA. I. Physikalisches Institut, Universität zu Köln, 50937 Cologne, Germany. 8th International Conference on Atomic and Molecular Data and Their Applications,

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The CDMS View on Molecular Data Needs of Herschel , SOFIA, and ALMA

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  1. Holger S. P. Müller, C. P. Endres, J. Stutzki, S. Schlemmer The CDMS View on Molecular Data Needsof Herschel, SOFIA, and ALMA I. Physikalisches Institut, Universität zu Köln, 50937 Cologne, Germany 8th International Conference on Atomic and Molecular Data and Their Applications, ICAMDATA 2012, Sep. 30 – Oct. 4, 2012, NIST, Gaithersburg, MD, USA

  2. Acknowledgments • Bundesministerium für Bildung und Forschung (BMBF) • (German Department for Education and Research) via Herschel/HIFI ICC and German ALMA regional Center unfortunately not a stable support

  3. CF+J = 3 – 2 APEX CF+J = 2 – 1 IRAM 30m CF+J = 1 – 0 IRAM 30m Detection of CF+ toward the Orion Bar D. A. Neufeld et al., Astron. Astrophys.454 (2006) L37 Rest frequencies required for line identification! Also for extragalactic CO observations!

  4. CDMS Main Page release of test version of database environment will be announced here two posters (27, 28) on VAMDC by M. L. Dubernet on Wednesday

  5. CDMS Catalog: Basic Facts • line lists of rotational spectra for molecules of interest in space • using tested Hamiltonian models based on critically evaluated experimental data • separate entries for isotopologues and vibrational states • 657 different species; 279 detected in ISM or CSE (Sep. 2012) • ~5 new entries each month • ~2000 accesses each month • included in many advanced astronomy tools, e.g. for Herschel

  6. Why Evaluate Experimental Data or Hamiltonian? • Experimental uncertainties are sometimes • – not reported • – too optimistic or too pessimistic • – not related to reported residuals • Treatment of blended lines may be incorrect • The Hamiltonian may be • – incomplete • – too extensive • – incompletely diagonalized Example NaCN: H. S. P. Müller et al., J. Mol. Spectrosc.272 (2012) 23

  7. Entries Documentation Name/Formula Species tag.: mw5# MHz Entry cm–1

  8. Example of a Current Documentation

  9. How can we raise the visibility of spectroscopic work ? • With annotated line lists:

  10. And Literature File

  11. CO entry Explanations with link to further details Frequency (MHz) Uncertainty (MHz) Elower (cm–1) Quantum numbers Intensity (nm2MHz) Species tag gup

  12. Considerations for Herschel, SOFIA, APEX, etc. • after Wilhelm/William & Caroline Herschel • − Heterodyne Instrument for the Far-Infrared • high-resolution; 0.48−1.25, 1,44−1.91 THz • − SPIRE & PACS; med.-res.; 0.6−5.2 THz • Astron. Astrophys.518, 521 (2010) letters • Stratospheric Observatory for Far-Infrared Applications • − high-res.: German REceiver At Terahertz Frequencies • ~1.3, 1.8, 2.5 THz; more with up-GREAT • Astron. Astrophys.542 (2012) letters • Atacama Pathfinder Experiment • − high.-res.; several atmospheric windows < 1.5 THz • Astron. Astrophys.454 (2006) letters

  13. Goals and Findings of Herschel • major goals: • − atomic fine structure lines (C+, N+, O) • − O2, low-lying lines of cold H2O • − high-lying lines of CO, HCN, HNC, HCO+, etc. • − (fundamental) transitions of light hydrides (AHn(+)) • − complex molecules, e.g. CH3OH, CH3OCH3 • important findings: • − there is O2 in the ISM, albeit very little: • P. F. Goldsmith et al., ApJ737 (2011) 96; R. Liseau et al., A&A541 (2012) A73 • − abundance of H2O varies greatly • − extensive observations of light hydrides, e.g. • CH+, CH, NH3, NH2, NH, OH, H3O+, HF • − most complex molecules hard to see • − very abundant SiC2 around CW Leo (IRC +10216): • H. S. P. Müller et al., J. Mol. Spectrosc.271 (2012) 50

  14. Detection of H2O+ with HIFI/Herschel Sgr B2(M) DR 21 NGC 6334 V. Ossenkopf et al., Astron. Astrophys. 518 (2010) L111

  15. Other Detections of Light Hydrides • ND, HIFI/Herschel: A. Bacmann et al., A&A521 (2010) L42 • OH+, APEX: F. Wyrowski et al., Astron. Astrophys.518 (2012) A26; (+ Herschel) • OD, GREAT/SOFIA: B. Parise et al., A&A542 (2012) L5 • SH+, APEX: K. M. Menten et al., A&A525 (2010) A77; (+HIFI/Herschel) • SH, GREAT/SOFIA: D. A. Neufeld et al., A&A542 (2012) L6 • H2Cl+, HIFI/Herschel: D. C. Lis et al., A&A521 (2010) L9 • HCl+, HIFI/Herschel: M. De Luca et al., ApJ751 (2012) L37

  16. Data Needs of Herschel etc. • light hydrides: CH2+, H2S+ • detected or known hydrides, complex molecules: • ALMA related: highly rot. or vib. excited lines • minor isotopic species • some features remain unassigned, e.g.:

  17. A submillimeter Diffuse Interstellar Band spiral arm clouds spiral arm clouds Sgr B2(N) Sgr B2(M) spiral arm clouds spiral arm clouds

  18. Considerations for ALMA (Atacama Large Millimeter Array) Interferometry  spatial resolution useful for the study of • (galaxies) • star-forming regions • (complex molecules) Chilean Andes, 5100 m • circumstellar envelopes of late-type stars • (composition, dust formation) • (circumstellar envelopes of young stars)

  19. Star-forming Regions • dense molecular clouds (> 1000 H2/cm3) • prestellar: cold (~10 K), more unsaturated molecules • very yound stars: warm (~50 K) to hot (> 200 K) • more saturated molecules • rich in complex molecules

  20. Difficulties to Detect Complex Molecules • larger molecules are usually rarer, • have more rotational and vibrational levels, • maybe several conformers  less favorable partition function • larger molecules are frequently less volatile  the weak lines may be blended with stronger lines  interferometry may be required for detection or confirmation  detection maybe better (well) below Boltzmann peak

  21. IRAM 30m PdBI, ATCA Detection of a Complex Organic Molecule: Aminoacetonitrile • H2NCH2CN (a likely precursor of glycine, H2NCH2COOH) A. Belloche et al., Astron. Astrophys.482 (2008) 179

  22. Other Recent Detections • n-propyl cyanide (C3H7CN) & ethyl formate (C2H5OCHO) • A. Belloche et al., Astron. Astrophys.499 (2009) 215 • high energy conformer (~1800 K) of methyl formate (CH3OCHO) • J. L. Neill et al., Astrophys. J.755 (2012) 153 • not yet glycine (H2NCH2COOH) • L. E. Snyder et al., Astrophys. J.619 (2005) 914

  23. Data Needs Concerning Complex Molecules • organic molecules with 3 to 6 heavy atoms • (many studied, many not; some already detected) • consider detections, expect surprises • also needed: data for excited states or rarer isotopologs • of already detected molecules, e.g.:

  24. HNCO in Sgr B2(N)v= 0, v5 = 1 (831K), v6 = 1 (944K), v4 = 1 (1117K) previously in G10.47+0.03: Wyrowski et al; A&A381 (1999) 882

  25. CH312/13CN, v8 = 1 in Sgr B2(N)

  26. Circumstellar Shells of Late-Type Stars • phases between H burning and white dwarf/(super) nova • (most) important contributors to interstellar dust • different flavors: C-rich, O-rich, [C] ≈ [O]

  27. C-rich Late-Type Stars • examples: CW Leo (IRC +10216), CRL 618, CRL 2688 • findings: CO, C-chain molecules, Si molecules, • metal halides, cyanides, isocyanides • recent findings: • anions, e.g. C6H−, M. C. McCarthy et al., ApJ652 (2006) L141, • C5N−, J. Cernicharo et al., ApJ688 (2008) L83; • FeCN, L. N. Zack et al., ApJ733 (2011) L36 • data needs: metal halides, (iso-) cyanides, etc., some anions

  28. O-rich Late-Type Stars • examples: VY CMa, IK Tau • findings: CO, HCN, various oxides and some sulfides • recent findings: PO, AlO, AlOH • E.D. Tenenbaum et al., ApJ 666 (2007) L29; 694 (2009) L59; 712 (2010) L93 • data needs: metal oxides, hydroxides, sulfides, etc.

  29. On Molecules in Space: http://www.astro.uni-koeln.de/cdms/molecules • Galactic and Extragalactic lists are up-to-date • Added or updated documentations on detections

  30. What about entries generated by other programs ? • We do accept predictions generated by other programs (e.g. BELGI) ! • We do need about the same pieces of information: • Frequencies with uncertainties and quantum numbers • Some form of intensity information – Sµ2 or A are fine • An energy file containing at least all states in the prediction • Q and gI or gup values • Some form of documentation and an experimental line list

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