Herschel observations of EXtra-Ordinary Sources (HEXOS): detecting spiral arm clouds by CH absorption lines
Artikel i vetenskaplig tidskrift, 2010

We have observed CH absorption lines (J = 3/2, N = 1 <- J = 1/2, N = 1) against the continuum source Sgr B2(M) using the Herschel/HIFI instrument. With the high spectral resolution and wide velocity coverage provided by HIFI, 31 CH absorption features with different radial velocities and line widths are detected and identified. The narrower line width and lower column density clouds show "spiral arm" cloud characteristics, while the absorption component with the broadest line width and highest column density corresponds to the gas from the Sgr B2 envelope. The observations show that each "spiral arm" harbors multiple velocity components, indicating that the clouds are not uniform and that they have internal structure. This line-of-sight through almost the entire Galaxy offers unique possibilities to study the basic chemistry of simple molecules in diffuse clouds, as a variety of different cloud classes are sampled simultaneously. We find that the linear relationship between CH and H-2 column densities found at lower AV by UV observations does not continue into the range of higher visual extinction. There, the curve flattens, which probably means that CH is depleted in the denser cores of these clouds.

sagittarius b2

sight-line

spectroscopy

ISM: abundances

chemistry

molecular clouds

ISM: molecules

g10.6-0.4

microwave

cologne database

submillimeter

hydrogen

Författare

S. L. Qin

Universität zu Köln

P. Schilke

Max-Planck-Gesellschaft

Universität zu Köln

C. Comito

Max-Planck-Gesellschaft

T. Moller

Universität zu Köln

R. Rolffs

Max-Planck-Gesellschaft

Holger Muller

Universität zu Köln

A. Belloche

Max-Planck-Gesellschaft

K. M. Menten

Max-Planck-Gesellschaft

D. C. Lis

California Institute of Technology (Caltech)

T. G. Phillips

California Institute of Technology (Caltech)

E. A. Bergin

University of Michigan

T. A. Bell

California Institute of Technology (Caltech)

N. R. Crockett

University of Michigan

G. A. Blake

California Institute of Technology (Caltech)

S. Cabrit

LUTH - Laboratoire de l'Univers et de ses Theories

E. Caux

LUTH - Laboratoire de l'Univers et de ses Theories

Université de Toulouse

C. Ceccarelli

Laboratoire d'Astrophysique de l'Observatoire de Grenoble

J. Cernicharo

Centro de Astrobiologia (CAB)

F. Daniel

LUTH - Laboratoire de l'Univers et de ses Theories

Centro de Astrobiologia (CAB)

M. L. Dubernet

LUTH - Laboratoire de l'Univers et de ses Theories

M. Emprechtinger

California Institute of Technology (Caltech)

P. Encrenaz

LUTH - Laboratoire de l'Univers et de ses Theories

E. Falgarone

LUTH - Laboratoire de l'Univers et de ses Theories

M. Gerin

LUTH - Laboratoire de l'Univers et de ses Theories

T. F. Giesen

Universität zu Köln

J. R. Goicoechea

Centro de Astrobiologia (CAB)

P. F. Goldsmith

Jet Propulsion Laboratory, California Institute of Technology

H. Gupta

Jet Propulsion Laboratory, California Institute of Technology

E. Herbst

Ohio State University

C. Joblin

LUTH - Laboratoire de l'Univers et de ses Theories

D. Johnstone

National Research Council Canada

W. D. Langer

Jet Propulsion Laboratory, California Institute of Technology

S. D. Lord

California Institute of Technology (Caltech)

S. Maret

Laboratoire d'Astrophysique de l'Observatoire de Grenoble

P. G. Martin

Institut canadien d'astrophysique théorique

G. J. Melnick

Harvard-Smithsonian Center for Astrophysics

P. Morris

Jet Propulsion Laboratory, California Institute of Technology

J. A. Murphy

Maynooth University

D. A. Neufeld

Johns Hopkins University

V. Ossenkopf

Universität zu Köln

Netherlands Institute for Space Research (SRON)

L. Pagani

LUTH - Laboratoire de l'Univers et de ses Theories

J. C. Pearson

Jet Propulsion Laboratory, California Institute of Technology

M. Perault

LUTH - Laboratoire de l'Univers et de ses Theories

R. Plume

University of Calgary

M. Salez

LUTH - Laboratoire de l'Univers et de ses Theories

S. Schlemmer

Universität zu Köln

J. Stutzki

Universität zu Köln

N. Trappe

Maynooth University

F. F. S. van der Tak

Netherlands Institute for Space Research (SRON)

C. Vastel

LUTH - Laboratoire de l'Univers et de ses Theories

Université de Toulouse

S. Wang

University of Michigan

H. W. Yorke

Jet Propulsion Laboratory, California Institute of Technology

S. Yu

Jet Propulsion Laboratory, California Institute of Technology

J. Zmuidzinas

California Institute of Technology (Caltech)

A. Boogert

California Institute of Technology (Caltech)

R. Güsten

Max-Planck-Gesellschaft

P. Hartogh

MPI für Sonnensystemforschung

N. Honingh

Universität zu Köln

A. Karpov

California Institute of Technology (Caltech)

J. Kooi

California Institute of Technology (Caltech)

J. M. Krieg

LUTH - Laboratoire de l'Univers et de ses Theories

R. Schieder

Universität zu Köln

M. C. Diez-Gonzalez

Observatorio de Yebes (IGN)

R. Bachiller

Observatorio de Yebes (IGN)

J. Martin-Pintado

Centro de Astrobiologia (CAB)

W. Baechtold

Eidgenössische Technische Hochschule Zürich (ETH)

Michael Olberg

Chalmers, Rymd- och geovetenskap, Onsala rymdobservatorium

L. H. Nordh

Stockholms universitet

J. L. Gill

Jet Propulsion Laboratory, California Institute of Technology

Goutam Chattopadhyay

Jet Propulsion Laboratory, California Institute of Technology

Astronomy and Astrophysics

0004-6361 (ISSN) 1432-0746 (eISSN)

Vol. 521 1 Art. no. L14 - L14

Ämneskategorier

Astronomi, astrofysik och kosmologi

DOI

10.1051/0004-6361/201015107

Mer information

Senast uppdaterat

2020-04-30