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

1
The CDMS View on Molecular Data Needsof
Herschel, SOFIA, and ALMA
Holger S. P. Müller, C. P. Endres, J. Stutzki, S.
Schlemmer
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
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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
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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 !
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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
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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

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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
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Entries
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Example of a Current Documentation
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How can we raise the visibility of spectroscopic
work ?

• With annotated line lists

J' Ka' Kc' J" Ka" Kc" Frequency Frequency Unc. Source
1 0 1 0 0 0 1370084 .880 0.020 /Asvany et al., 2008
1 1 0 1 1 1 372421 .385 0.010 /Amano and Hirao, 2005
2 0 2 1 0 1 2576759 .63 0.91 /Amano, 2006 Yonezu et al., 2009
2 1 2 1 1 1 2363242 .82 0.69 /Yonezu et al., 2009
2 1 1 1 1 0 3102329 .15 0.56 /Amano, 2006 Yonezu et al., 2009
2 2 0 2 2 1 155987 .185 0.037 /Saito et al., 1985
3 1 3 2 1 2 3453653 .20 0.44 /Amano, 2006 Yonezu et al., 2009
3 2 1 3 2 2 646430 .295 0.050 /Amano and Hirao, 2005
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And Literature File
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CO entry
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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 lt 1.5
  THz

• Astron. Astrophys. 454 (2006) letters

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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., ApJ 737 (2011) 96 R.
  Liseau et al., AA 541 (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

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

• ND, HIFI/Herschel A. Bacmann et al., AA 521
  (2010) L42

• OH, APEX F. Wyrowski et al., Astron.
  Astrophys. 518 (2012) A26 ( Herschel)

• OD, GREAT/SOFIA B. Parise et al., AA 542
  (2012) L5

• SH, APEX K. M. Menten et al., AA 525 (2010)
  A77 (HIFI/Herschel)

• SH, GREAT/SOFIA D. A. Neufeld et al., AA 542
  (2012) L6

• H2Cl, HIFI/Herschel D. C. Lis et al., AA 521
  (2010) L9

• HCl, HIFI/Herschel M. De Luca et al., ApJ 751
  (2012) L37

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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.

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

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Star-forming Regions

• dense molecular clouds (gt 1000 H2/cm3)

• prestellar cold (10 K), more unsaturated
  molecules

• very yound stars warm (50 K) to hot (gt 200 K)
• more saturated
  molecules
• rich in complex
  molecules

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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
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Detection of a Complex Organic Molecule
Aminoacetonitrile

• H2NCH2CN (a likely precursor of glycine,
  H2NCH2COOH)
• A. Belloche et al., Astron. Astrophys. 482
  (2008) 179

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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

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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.

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HNCO in Sgr B2(N)v 0, v5 1 (831 K), v6 1
(944 K), v4 1 (1117 K)
previously in G10.470.03 Wyrowski et al AA
381 (1999) 882
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CH312/13CN, v8 1 in Sgr B2(N)
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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

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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., ApJ
  652 (2006) L141,
• C5N-, J. Cernicharo et al., ApJ 688 (2008)
  L83
• FeCN, L. N. Zack et al., ApJ 733 (2011) L36

• data needs metal halides, (iso-) cyanides,
  etc., some anions

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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.

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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

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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