Holger S. P. Müller, Jürgen Stutzki, Stephan Schlemmer

I. Physikalisches InstitutUniversität zu Köln

50937 Cologne, Germany

The Cologne Database for Molecular Spectroscopy, CDMS,in Times of Herschel, SOFIA and ALMA

64th International Symposium on Molecular Spectroscopy; WH07

Overview

I. Introduction

II. The CDMS

IV. Considerations for Herschel and SOFIA

V. Considerations for ALMA

III. Other Resources

Selected Terahertz Observatories

APEXrunning≤ 1.5 THz~ 5100 m

SOFIA, ~ 2010, ~ 3 THz

ALMA~ 2012

≤ 0.72 THz~ 5100 m

Herschel Space Obs., running, ≤ 2 (5) THz

The Transmissivity of the Atmosphere

3135 m 5612 m ~ 13000 m

H2O is the main absorber

Detection of CF+ toward the Orion Bar

CF+ J = 3 – 2 APEX

CF+ J = 2 – 1 IRAM 30m

CF+ J = 1 – 0 IRAM 30m

D. A. Neufeld et al., Astron. Astrophys. 454 (2006) L37

Rest frequencies required for line identification !

Also for extragalactic CO observations !

CDMS Main Page

Please bookmark as http://www.astro.uni-koeln.de/cdms/

Short-cut to CDMS main page: www.cdms.de

CDMS catalog: basic facts

line lists of rotational spectra for molecules of interest in space

Hamiltonian model based on experimental data

520 different species; 242 detected in ISM or CSE

separate entries for isotopologues and vibrational states

~ 1000 users each month

included in many advanced astronomy tools, e.g. for Herschel

~ 5−10 new entries each month

General

Entries

Species tag.: mw5#Name/Formula DocumentationMHz Entry cm–1

Entries Based on Laboratory Data, e. g., CO, v = 1

Important:appropriate uncertainties

J" frequency unc. o–c

1 228439.074 25 –27

2 342647.636 20 –6

3 456842.977 10 4

4 571020.677 12 –12

5 685176.392 5 2

6 799305.677 10 4

7 913404.136 5 –1

15 1824554.595 10 –0

16 1938177.832 10 0

B 57111.24312 (66)

D × 103 183.4903 (71)

H × 109 177.9 (145)

The Data

The Spectroscopic Parameters

R. Gendriesch et al., A&A 497 (2009) 927

Issues Around Experimental Uncertainties

The 12th commandment: Thou shalt not scale your parameter uncertainties with the rms error.

− reasons for rms error < 1: small data set; systematic errors (calibration); etc.

− reasons for rms error > 1: wrong model, e.g. missing parameter; etc.

Measure calibration lines if you are uncertain how well you can do.

− Lab: CO, H2CO, CH3CCH, CH3CN, OCS, SO2, etc.

− Astro: dito, (CCH soon), HCN, HCO+, N2H+, HC3N, HC5N, etc.

CO entryExplanations with link to further detailsFrequency (MHz)Uncertainty (MHz)Elower (cm–1)gupSpecies tagQuantum numbersIntensity (nm2MHz)

Example for a documentation

Lots of information on entry:source of datainformation on moleculecaveat(s)links to special data (hfs)etc.

search (default)

Graphic Output for SO2 at 150 K

What’s New

Molecules in Space

H3+ in ISM

fitting spectra

examples

Other Databases

JPL catalog: http://spec.jpl.nasa.gov/ atmospheric and astrophysical species; WH09, B. J. Drouin & J. C. Pearson

HITRAN: http://www.cfa.harvard.edu/HITRAN/ atmospheric species; RI01, L. S. Rothman & I. E. Gordon

NIST Rec. Rest Frequencies: http://physics.nist.gov/cgi-bin/micro/table5/start.pl astrophysical species, observed lines only (F. J. Lovas); peculiar uncertainties

SLAIM: F. J. Lovas’ extension of NIST RRF; via splatalogue; peculiar uncertainties

Examples for 3rd Level Resources

CASSIS: http://www.cesr.fr/~walters/web_cassis/ Adam Walters et al.; CDMS + JPL + astro tools

splatalogue: http://www.splatalogue.net/ under construction; CDMS, JPL, NIST RRF, SLAIM, Recomb. often many options for one species

The 3rd level needs the 2nd and 1st as the 2nd needs the 1st(the original lab work).

Note: Consolidation is not always a simple task !Newest entry ? Most experimental data ? Highest quantum numbers or frequencies ?

Considerations for Herschel and SOFIA

Molecular Lines at Terahertz Frequenciesatm

ospheric transmission / %

CSO line survey of Orion-KL, C. Comito et al, ApJS 156 (2005) 127167

Detail of the Interstellar Carbon Cycle

CH3+

CH2+

HCO+

CH2

CH

C

CO

CH+

C+ CO+

millimeter lines (>)submillimeter lines

terahertz lines

H2

H2

H

H

H

e

ee

e

e, ν

e

H3+

ν

ν

ν

ν

H, ν

OH

O

He+O2

e, S

H2

H2, H2*H2*

ν, C+

OH

adopted from Sternberg & Dalgarno, 1995

Probing Cold CH2 in the THz Region toward Sgr B2

E. T. Polehampton et al., A&A 431 (2005) 203(analyzing ISO data)

CH 2Π½, J = 1.5 – 0.5 @ 2.011 THz

o-CH2, 111 – 000 @ 2.349 THz

p-CH2, 212 – 101 @ 2.783 THz

o-CH2, 313 – 202 @ 3.201 THz

Detection of 13CH+ J = 1 − 0 toward G10.6−0.4 with the CSO

E. Falgarone et al., ApJ 634 (2005) L149

CH3OH

13CH+

no accurate 13CH+ lab data no kinematic information

CO, J = 13 − 12 @ 1.497 THz, Detected with APEX

Hot core in OMC-1

near or at interface between HII and compact mol. gas

Hot gas component (300 – 500K)

at vertex of system of outflows.

CO 13 12

M. C. Wiedner et al.,A&A 454 (2006) L33

Light Hydride Species AHn in the CDMS Catalog

H2D+, HD2+, HeH+, NeH+, ArH+

BH, CH, CH+, CH2, CH2D+, CH3D, 13CH3D

NH, ND, NH2, NH3, OH+, OH−, D2O, H3O+, H2DO+

PH, PH2, PH3, SH−, SH+, H2S

NaH, MgH, KH, CuH, ZnH

plus more to come

detected in ISM/CSE; several isotopologs

(Possible) Data Needs

desired species: CH+, 13CH+, CD+ !13CH2, CHDCH2

+, NH2+, H2O+ ?

(interfering) species: CH3OH isotopologs

other "weeds" mostly as for ALMAmostly v = 0 & main isotopologmaybe higher frequencies on occasion

Considerations for ALMA

The Purported Detection of GlycineSgr B2(N-LMH)

Orion-KL

W51 e1/e2

Kuan et al.,ApJ 593 (2005) 848;(plus other lines)

Problems with the Purported Glycine Detection

many line overlaps; e.g. 206468 (left line) with CH3CH2CN, v13 = 1a 240899 (right line) with CH3

13CH2CNb

many lines are "missing" (too weak) purported abundances too high

a) Snyder et al., ApJ 619 (2005) 914; adopted from Nummelin et al.ApJS 117 (1998) 427

b) HSPM, CDMS

Sgr B2(N-LMH)

A Solution for Single Dish Radio Telescopes

Unbiased Molecular Line Surveysin large frequency windows

Detection of a Complex Organic Molecule: Aminoacetonitrile H2NCH2CN (a likely precursor of glycine, H2NCH2COOH)

A. Belloche et al., Astron. Astrophys. 482 (2008) 179

IRA

M 3

0m

PdB

I, A

TC

A

C2H3CN, v = 0, + 13C, + 15N H. S. P. Müller et al., J. Mol. Spectrosc. 251 (2008) 319

Detection of 13C-Vinyl Cyanide

HNCO in Sgr B2(N)v = 0, v5 = 1 (831 K), v6 = 1 (944 K), v4 = 1 (1117 K)

previously in G10.47+0.03: Wyrowski et al; A&A 381 (1999) 882

The Blessing and the Curse of ALMA

very high sensitivity & very high spatial resolution

much rarer species may be seen

e.g. more complex molecules . . .

. . . but interfering species as well !(Weeds; molecules with many lines in star-forming region.)

The Weeds Issue

Examples: CH3OH, CH3CN, C2H3CN, C2H5CN, HC3N, CH3OCH3, CH3C(O)CH3, CH3OCHO, SO2

− main isotopolog, v = 0 generally in good or fairly good shape

− minor isotopologs, v = 0 good or reasonable for several species; more data to come

− main isotopolog, excited states good or reasonable for some species; more data to come; tedious, but important: C2H5CN

− minor isotopologs, exited states in good shape only rarely; data probably needed for some species, especially 13C

Acknowledgments

DFG (Deutsche Forschungsgemeinschaft) → 2006

BMBF (Bundesministerium für Bildung und Forschung) (for Herschel/HIFI)

Spectroscopists for measurements and providing data

Astronomers for suggestions and comments on the CDMS