The Submillimeter Spectrum of the Orion Star Forming Region

Mary L. Radhuber, Jay A. Kroll, Susanna L. Widicus WeaverDepartment of Chemistry

Emory University

Why Line Surveys?

Large swaths of frequency covered in single observations

More observed transitions leads to better identification certainty.

Large amounts of data are acquired in short amounts of time.

Similar instrument and calibration conditions for an entire observation

Better internal consistency of intensity measurements leads to a more accurate measurement of physical conditions.

2 atoms

3 atoms

4 atoms

5 atoms

6 atoms

7 atoms

8 atoms

9 atoms

10 atoms

11 atoms

12 atoms

13 atoms

H2 C3 c-C3H C5 C5H C6H CH3C3N CH3C4H CH3C5N HC9N C6H6 HC11N

AlF C2H l-C3H C4H l-H2C4 CH2CHCN HC(O)OCH3 CH3CH2CN (CH3)2CO CH3C6H C2H5OCH3

AlCl C2O C3N C4Si C2H4 CH3C2H CH3COOH (CH3)2O (CH2OH)2

C2 C2S C3O l-C3H2 CH3CN HC5N C7H CH3CH2OH CH3CH2CHO

CH CH2 C3S c-C3H2 CH3NC CH3CHO H2C6 HC7N

CH+ HCN C2H2 H2CCN CH3OH CH3NH2 CH2OHCHO C8H

CN HCO NH3 CH4 CH3SH c-C2H4O l-HC6H CH3C(O)NH2

CO HCO+ HCCN HC3N HC3NH+ H2CCHOH CH2CHCHO C8H–

CO+ HCS+ HCNH+ HC2NC HC2CHO C6H– CH2CCHCN C3H6

CP HOC+ HNCO HCOOH NH2CHO

SiC H2O HNCS H2CNH C5N

HCl H2S HOCO+ H2C2O l-HC4H

KCl HNC H2CO H2NCN l-HC4N

NH HNO H2CN HNC3 c-H2C3O

NO MgCN H2CS SiH4 H2CCNH

NS MgNC H3O+ H2COH+

NaCl N2H+ c-SiC3 C4H–

OH N2O CH3

PN NaCN

SO OCS

SO+ SO2

SiN c-SiC2

SiO CO2

SiS NH2

CS H3+

HF H2D+, HD2+

SH SiCN

HD AlNC

FeO SiNC

O2 HCP

CF+

SiH

PO

>150 Molecules Detected

H. S. P. Müller, F. Schlöder, J. Stutzki, and G. Winnewisser,J. Mol. Struct. 742, 215–227 (2005)

H. S. P. Müller, S. Thorwirth, D. A. Roth, and G. Winnewisser,Astron. Astrophys. 370, L49–L52 (2001)

Previous Surveys of Orion KLOVRO survey

215 – 263 GHzRMS ~150 mK

800 resolved spectral features29 molecular species IDed

CSO survey325 – 360 GHzRMS ~250 mK

717 resolved spectral features34 molecular species IDed

IRAM 30m survey80-115.5, 130-178, 197-281 GHz

RMS ~20 mK14,400 resolved spectral features

191 molecular species IDed

Assignment Progress

Lines Observed 5378

Lines Identified 1094 (20.34%)

Unidentified Lines 4284 (79.66%)

RMS 30 mKSimilar Surveys Completed for 4 other star forming regions and partial coverage on 7 other sources

Molecule Previously Observed Transitions Newly Observed Transitions

HDO 2 1

CN 11 1

CO 2 0

DNC 1 0

C17O 1 0

H2CO 1 1

CH3CCH 2 4

HNCO 3 0

C33S 1 013CS 1 1

C34S 1 1

CH3CHO 4 45

CH3OH 43 3813CH3OH 11 39

HCOOCH3 105 169

CH3OCH3 13 64

HC3N 7 28

C2H3CN 30 46

Assignment Progress

Assignment ProgressMolecule Previously Observed Transitions Newly Observed Transitions

13CH3CN 7 3

CH313CN 1 2

CH2CO 1 2

H2CS 7 2

CH3CN 20 7

HCOOH 7 6

C2H5CN 55 19

OCS 2 0

O13CS 1 1

OC34S 1 2

SO2 19 834SO2 8 12

CH3NH2 0 12

CH3NO 0 12

CH3CH2OH 0 74

C3H6O 0 70

C2H6O2 0 28

CH2DCN 0 15

Other Observatories

ALMA (ESO / NAOJ / NRAO) photo by Nick Whyborn, 3 June 2010.

ALMA

Herschel/HIFI

SOFIA

http://www.sofia.usra.edu/

http://www.esa.int/esaSC/SEMIO99L6VE_index_0.html

Existing Laboratory Analysis Programs

• Do not account for observational parameters (beam properties, telescope efficiency)

• Cannot input or determine physical parameters of source (temperature, column density, velocity, structure)

Existing Observational Analysis Programs

• Can only fit physical parameters for one molecule at a time

• Restricted options for spectral simulation and fitting

• Relies on older versions of catalogs

Program Requirements

• Automated line identification for multiple species

• Least squares analysis of spectrum for multiple species with multiple physical parameters

• Automated global analysis of physical conditions

• Ability to update laboratory spectral data for observational comparison

Assignment Methods

Assignment Methods

Assignment Methods

• Automated Line Identification

• Automated Line Fitting

• Automated Boltzmann Analysis

Program Goals

AcknowledgementsThe Widicus Weaver Group:

Thomas AndersonBrandon CarrollJay KrollJacob LaasPatrick LanterBrett McGuireSusanna Widicus Weaver

Caltech/CSO:

Matthew SumnerDarek LisFrank RiceTom PhillipsGeoffrey BlakeCSO Local Staff