Recent Developments in the Cologne Database for Molecular Spectroscopy, CDMS, and the Need for Further Laboratory Spectroscopy

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Recent Developments in the Cologne Database for
Molecular Spectroscopy, CDMS, and the Need for
Further Laboratory Spectroscopy
Ninth Biennial HITRAN Conference, 26 28 June
2006, Harvard Smithsonian Center for
Astrophysics, Cambridge, MA
Holger S. P. Müller MPIfR, Bonn, Germany I.
Physikalisches Institut, Universität zu Köln,
Germany
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Selected Terahertz Observatories
ALMA 2012
APEX running
Herschel Space Obs. 2008
SOFIA 2008
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Home
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CDMS Catalog Basic Facts

• line lists for molecules of astrochemical and
  astrophysical interest
• not restricted to observed species

• separate entries for different molecules,
  isotopic species, vibrational states

• entries created from fitting existing
  (laboratory) data

• only such catalog publically available besides
  that from JPL

• entries for 378 species (up from 234 two years
  ago) 181 have been detected

• 5 10 new or updated entries each month

• important source of spectroscopic information
  for many web tools

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What Do We Want from Laboratory Spectroscopists ?

• experimental line lists in particular also for
  IR data

• evaluate uncertainties critically and state
  them

• electronic files can be helpful

• publication of predictions not necessary for
  standard problems

• in case of predictions for non-standard problems
• consider sufficient quantum number range
• provide info. on I, Sµ2, or A
• provide info. on Q (including treatment of
  spin-statistic)

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What Do We Want from Observers ?

• which molecule needs attention

• which isotopic species need consideration

• some indications on the quantum number range
• (including that for vibrations)

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What Do We Offer ?

• transition frequencies with uncertainties

• I _at_ 300 K (or selected other Ts) or Sµ2 or A

• quantum numbers

• Elower, gup etc.

• background information on species

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documentation
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CO entry
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search (default)
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Graphic Output for SO2 at 150 K
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general format
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fitting spectra
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examples
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molecules in space
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Beispiel CH2 im ISM
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whats new ?
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Complex Molecules in the CDMS Catalog
c-C2H4O c-C2H4NH c-H2C3O c-H2C3CH2 c-C6H4
C2H3NH2 C2H3OH C2H3CCH C3H3CN n-C3H7OH
HC(O)CN NCC(O)NH2 NCHCCO
glycolaldehyde ethylene glycol diethyl
ether glycine
species detected in ISM/CSS
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The Quest for Complex Molecules, e.g. CH2OHCHO
is often hampered by U-lines, D. T. Halfen et
al., ApJ 639 (2006) 237
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The U-line Issue

• already many detected in surveys with IRAM 30 m,
  Odin, CSO etc.

• desired line may be overlapped by U-line
• (e.g. O2 _at_ 424763 MHz obs. with SWAS ?)

• U-lines may be due to

• high r or v lines of known compounds, e.g. CH3OH

• isotopic species of known molecules, e.g. CH3OH

• new, maybe exotic species

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Do we have to consider vibrational satellites as
weed only ?

• several states 1100 cm 1 ? 1600 K
• plus 13C data
• physical model of CRL 618
• F. Wyrowski et al., ApJ 586 (2003) 344

similar study on HC3N in CRL 618 J. R. Pardo et
al., ApJ 615 (2004) 495
vibrationally excited HC3N toward hot cores e.g.
F. Wyrowski, AA 341 (1999) 882
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What do we need to know ? Selected case studies

• alcohols CH3OH, C2H5OH, n,i-C3H7OH

• ethers CH3OCH3, C2H5OCH3, C2H5OC2H5

• sat. cyanides CH3CN, C2H5CN, n,i-C3H7CN

• cyanopolyynes HC3N, HC5N, HC7N

(CH3CHO, CH3OCHO)
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Methanol, CH3OH, I
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Methanol, CH3OH, II
also needed 13CH2DOH, 13CH3OD, CHD2OD, ?t 0
? 1 THz
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Ethanol, C2H5OH (1 2 conf. a g)

• needed for C2H5OH ?t 1 ? gtgt 1 THz

• available for ?t 0 ? 0.5 THz soon more
  from JPL

• available for ?t gt 0 some lines 60 GHz

• needed for C2H5OH-13C1 ?t 0 ? gtgt 1 THz

• available for ?t 0 some lines 60 GHz (in
  part from PhD thesis)

• are 13C2, 18O, or D1 species needed ?

(Far-) infrared data very useful at least for
main isotopic species
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n,i-Propanol, C3H7OH (2 isom., several conf.)

• needed ?t 0 ? 0.x THz for 2 isom., lowest
  conf.

• available ? 0.35 THz for Ga-conf. of n-isom.

• more to come from OSU

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Butanol, C4H9OH (4 isomers . . .)
not (urgently) needed
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Dimethyl ether, CH3OCH3
maybe not needed 18O (?), 13C2, D1
(Far-) infrared data very useful at least for
main isotopic species
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Ongoing investigations of CH3OCH3

• measurements at Köln and at JPL
• main species ? 0 ready soon !?
• higher ? to follow
• 13C1 ? 0 intended

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Ethyl methyl ether (EME) and diethyl ether (DEE)
needed ?t 0 ? ? 1 THz available ?t 0 ?
0.35 THz higher ? in Köln (?)

• EME

needed ?t 0 ? 1 THz for aa-conf. available
?t 0 ? 0.35 THz for aa- and ag-conf.

• DEE

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Methyl cyanide, CH3CN
also needed 13C2, 15N, D1
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Ongoing investigations of CH3CN

• measurements at Köln and at JPL
• CH3CN ?8 3
• 13C1 ?8 2 (?)
• 15N ?8 0 or 1
• 13C2 ?

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Ethyl cyanide, C2H5CN
maybe not needed 15N (?), 13C3, D1
(Far-) infrared data very useful at least for
main isotopic species
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n,i-Propyl cyanide, C3H7CN

• ? 0 ? 0.3 THz known for a- and g-conformers
  of n-isomer

• just some MW lines known for conformers of
  i-isomer

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Cyanopolyynes

• HC3N FIR and IR data needed for many states
  for 13C

• HC5N FIR and IR data needed at least for main
  isotopic species

• HC7N FIR, maybe IR, data needed at least for
  main isotopic species

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Acetaldehyde, CH3CHO
needed ?t 0 ? ? 1 THz (?) available ?t 4
? 0.25 THz FIR new measurements at JPL

• CH3CHO

also needed ?t 0 for 13C1, D1, 18O, . .
. available just a few lines each
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Available for methyl formate, CH3OCHO

• CH3OCHO, ?t 0 ? 0.6 THz
• ?t 1 ? 0.2 THz

• CH3O13CHO, ?t 0 ? 0.6 THz

• CH3OCDO, ?t 0 ? 0.4 THz

(Far-) infrared data very useful at least for
main isotopic species
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Rovibrational Transitions Available in the CDMS
Catalog
C3, ?2 C3O2, ?7 C2H2, ?5 ?4
CH3CCH, ?10, ?9 SO2, ?2 HC5N, ?7
species detected in ISM/CSM
often lab. data needed or difficult to obtain for
abundant species in (hot) ISM/CSS e.g. low
bending modes of Cn, CnH, PAHs
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Acknowledgments

• DFG SFB 494 (2003 2005)
• Prof. Karl Menten, MPIfR Bonn
• Profs. S. Schlemmer J. Stutzki, PH1, Köln
• Drs. S. Thorwirth, D. Roth, F. Schlöder