RESULTS FROM THE HEXOS FULL-BAND …herschel.esac.esa.int/TheUniverseExploredByHerschel/...RESULTS...

RESULTS FROM THE HEXOS FULL-BAND SPECTRAL SURVEY OF ORION SOUTH

René Plume & Kianoosh Tahani - U. of CalgaryTed Bergin - U. Michigan

The HEXOS TeamThe Universe Explored by Herschel - ESTEC - Oct 2013

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Edwin A. Bergin (PI)

Gisela Banos

Tom A. Bell

Arnaud Belloche

Olivier Berne

Geoffrey A. Blake

Paola Caselli

Emmanuel Caux

Cecilia Ceccarelli

José Cernicharo

Claudia Comito

Nathan Crockett

Fabien Daniel

Marie-Lise Dubernet

Martin Emprechtinger

Pierre Encrenaz

Maryvonne Gerin

Thomas Giesen

Javier R. Goicoechea

Paul Goldsmith

Harschal Gupta

Martin Harwit

Eric Herbst

Martin Houde

Willem Jellema

Christine Joblin

Doug Johnstone

Michael J. Kaufman

Di Li

Dariusz C. Lis

Steven D. Lord

Giuliano Malloci

Sébastien Maret

Peter G. Martin

Gary Melnick

Karl M. Menten

Giacomo Mulas

Holger Muller

J. Anthony Murphy

David A. Neufeld

Volker Ossenkopf

Juan R. Pardo

John C. Pearson

Michel Pérault

Thomas G. Phillips

Poalo Piller

René Plume

Sheng-Li Qin

Markus Röllig

Peter Schilke

Stephan Schlemmer

Robert Simon

Juergen Stutzki

Belen Tercero

Neil Trappe

Charlotte Vastel

Shiya Wang

Harold W. Yorke

Shanshan Yu

Jonas Zmuidzinas

HEXOS Team:

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BROAD PERSPECTIVE

• Stars are born in molecular clouds that exhibit a high degree of chemical complexity - clearly dominated by water, carbon monoxide, and carbon dioxide etc but there are many complex organics

• How this complexity develops is uncertain -- gas phase? catalytic chemistry on grain surfaces? What are the reaction rates and branching ratios of the first key reactions? What are the abundances of the key species?

• We can use the rich variety of chemical species to provide key understandings of the physical conditions in molecular clouds.

Plume - The Universe Explored by Herschel - ESTEC - Oct 2013

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SCUBA 450 μm

• Goals similar to KL but in different region

• IR luminosity 10x lower

• highly collimated CO outflow (~ 30 km/s)

• narrower lines (few km/s)

• fewer & weaker lines• May be at an earlier stage in its chemical evolution

Orion KL

Orion S

Orion Bar


4


5

60

40

20

0

T A* (K

)

18001600140012001000800600Frequency (GHz)

1.0

0.5

0.0

Transmission

E. Bergin6

Overall Data Quality

8


9



10


Orion KL

Orion S

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Line Identification • Using CASSIS we have

identified, and fit Gaussians to over ~ 400 transitions from 45 species

• Plus an additional ~100 U lines

• Focusing on the strong (S/N > 4-5) lines

• There are ~ 800 lines from ~47 species if we include lines w S/N ~ 3-4

• few complex molecules

- Tahani et al 2014C0 C18O p-H2O H13CO+

C+ 13C18O o-H2O HC18O+

CCH C17O H218O DCO+

CCD CS HDO HNC

CH+ C34S p-H2S N2H+

CH 13CS o-H2S o-NH3

E-CH3OH HCl H234S p-NH3

A-CH3OH H37Cl HCN NO

CN p-H2CO H13CN SH+

CO o-H2CO DCN SO13CO H2CS HCO+ SO2

SiO

http://cassis.irap.omp.eu

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Spectral Line Fitting C18O 5-4 C18O 6-5 C18O 7-6

C18O 8-7 C18O 9-8 C18O 10-9

C18O 11-10θ = 60” (fixed) ΔVFWHM = 3.9 km/sVLSR = 7.1 km/sN(C18O) = 3.0x1016 cm-2

Tex = 62 K

http://cassis.irap.omp.eu

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θ = 30” , ΔVFWHM = 13.7 km/s, VLSR = 6.6 km/s, N = 2.8x1013 cm-2, Tex = 74 Kθ = 60” (fixed), ΔVFWHM = 4.4 km/s, VLSR = 7.1 km/s, N = 1.9x1014 cm-2, Tex = 32 K

HCN 6-5 HCN 7-6 HCN 8-7

HCN 9-8 HCN 10-8 HCN 11-10

HCN 12-11 HCN 13-12

Spectral Line Fitting

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SCUBA 450 μm


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Courtesy of P. André and the Herschel Gould Belt survey (HGBS) project (A&A, 518, L102)

http://gouldbelt-herschel.cea.fr/archives

Herschel 70 μm

Polychroni et al., in prep.

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0.10

1.00

10.00

100.00

1,000.00

10,000.00CO

13C1

8O13

COC1

7OC1

8O CS

13CS

C34S

CCH CN

A-CH

3OH

E-CH

3OH

DCN

H2CS HC

lH3

7Cl

HCO+

H13C

O+ H2O

H218

OHD

OHC

NH1

3CN

HNC

H2CO H2

SH2

33S

H234

So-

NH3

NO SiO SO SO2

Hot Core / Orion S Compact Ridge / Orion S Plateau / Orion S Extended Ridge / Orion S

Emission PropertiesComparison with Orion KL

ER : <> = 3.0 σ = 3.7CR : <> = 15.8 σ = 17.2HC : <> = 157.3 σ = 291PL : <> = 309.1 σ = 666

RT

dV

(Ori

onK

L)

RT

dV

(Ori

onS

)

�

(N. Crockett et al. 2013)


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0.10

1.00

10.00

100.00

1,000.00

10,000.00CO

13C1

8O13

COC1

7OC1

8O CS

13CS

C34S

CCH CN

A-CH

3OH

E-CH

3OH

DCN

H2CS HC

lH3

7Cl

HCO+

H13C

O+ H2O

H218

OHD

OHC

NH1

3CN

HNC

H2CO H2

SH2

33S

H234

So-

NH3

NO SiO SO SO2


Emission PropertiesComparison with Orion KL

RT

dV

(Ori

onK

L)

RT

dV

(Ori

onS

)

�


Orion S• CO+13CO+C18O (70%)• CH3OH (9%)• HCO+ (9%)

Orion KL• CO+13CO+C18O (15%)• CH3OH (33%)• SO2 (18%)• H2O (10%)• SO (7%)


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0.10

1.00

10.00

100.0013

C18O

13CO

C17O

C18O CS

C34S

CCH CN DCN

H2CS HC

l

H37C

l

HCO+

H13C

O+

H218

O

HCN

H13C

N

HNC

H2S

o-NH

3

NO SiO SO SO2


Abundance VariationsComparison with Orion KL X

Orio

nK

L

XO

rio

nS

�

ER : <> = 2.3 σ = 1.9CR : <> = 16 σ = 51HC : <> = 207 σ = 837PL : <> = 30 σ = 99

N(H2) = 500x104xN(C18O)

Yunhee Choi P61



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0.10

1.00

10.00

100.0013

C18O

13CO

C17O

C18O CS

C34S

CCH CN DCN

H2CS HC

l

H37C

l

HCO+

H13C

O+

H218

O

HCN

H13C

N

HNC

H2S

o-NH

3

NO SiO SO SO2


Abundance VariationsWeak Shock Chemistry

XO

rio

nK

L

XO

rio

nS

�

N(H2) = 500x104xN(C18O)

SiO/HCO+ =0.1 (Orion S) = 5 (Plateau)SO2/HCO+ =2.2 (Orion S) = 183 (Plateau)SO/HCO+ =15.5 (Orion S) = 187 (Plateau)PL : <> = 30 σ = 99


20

0.10

1.00

10.00

100.0013

C18O

13CO

C17O

C18O CS

C34S

CCH CN DCN

H2CS HC

l

H37C

l

HCO+

H13C

O+

H218

O

HCN

H13C

N

HNC

H2S

o-NH

3

NO SiO SO SO2


Abundance VariationsEnhanced UV Chemistry?

XO

rio

nK

L

XO

rio

nS

�

N(H2) = 500x104xN(C18O)

CN/HCN=4.75 (Orion S) = 0.4 (Plateau) = 4 (Extended Ridge)C2H/HCO+ = 12.5 (Orion S)= 11 (Hot Core) = 3 (Extended Ridge)


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Conclusions• Covered 460-1900 GHz with spectral resolution of 1.1 MHz

• Identified & fit Gaussian profiles to over 300 transitions from 45 species

• Using LTE models, determined physical parameters for each of the species (N, Tex, etc.)

• Single, warm (40 - 60K) physical component works well in most cases

• 2 components (cool/narrow + warm/broad) needed in some instances

• Warm gas is fairly extended and possibly externally heated

• Orion S has chemical composition most similar to Orion KL Extended & Compact Ridges (except for H218O)

• no complex organics & poor fit to Hot Core no Hot Core chem

• poor fit to Plateau & low SiO, SO, SO2 abundances weak shock chem

• Evidence for UV chemistry

• Need chemical & RADEX modeling


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RESULTS FROM THE HEXOS FULL-BAND …herschel.esac.esa.int/TheUniverseExploredByHerschel/...RESULTS...

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