Nitrogen hydrides in interstellar gas Herschel/HIFI observations towards G10.6-0.4 (W31C)
Journal article, 2010
The HIFI instrument on board the Herschel Space Observatory has been used to observe interstellar nitrogen hydrides along the sight-line towards G10.6-0.4 in order to improve our understanding of the interstellar chemistry of nitrogen. We report observations of absorption in NH N = 1 <- 0, J = 2 <- 1 and ortho-NH2 1(1,1) <- 0(0,0). We also observed ortho-NH3 1(0) <- 0(0) and 2(0) <- 1(0), para-NH3 2(1) <- 1(1), and searched unsuccessfully for NH+. All detections show emission and absorption associated directly with the hot-core source itself as well as absorption by foreground material over a wide range of velocities. All spectra show similar, non-saturated, absorption features, which we attribute to diffuse molecular gas. Total column densities over the velocity range 11-54 km s(-1) are estimated. The similar profiles suggest fairly uniform abundances relative to hydrogen, approximately 6 x 10(-9), 3 x 10(-9), and 3 x 10(-9) for NH, NH2, and NH3, respectively. These abundances are discussed with reference to models of gas-phase and surface chemistry.
sagittarius-b2
molecular processes
clouds
molecular absorption
ISM: molecules
diffuse
submillimeter
chemistry
nh
line: formation
astrochemistry
sight-line
regions
ISM: abundances
submillimetre: ISM
spectroscopy
Author
Carina Persson
Chalmers, Earth and Space Sciences, Radio Astronomy and Astrophysics
John H Black
Chalmers, Earth and Space Sciences, Radio Astronomy and Astrophysics
J. Cernicharo
J. R. Goicoechea
G.E. Hassel
E. Herbst
M. Gerin
M. de Luca
T. A. Bell
A. Coutens
E. Falgarone
P. F. Goldsmith
H. Gupta
M. Kazmierczak
D. C. Lis
B. Mookerjea
D. A. Neufeld
J. C. Pearson
T. G. Phillips
P. Sonnentrucker
J. Stutzki
C. Vastel
S. Yu
F. Boulanger
E. Dartois
P. Encrenaz
T. R. Geballe
T. Giesen
B. Godard
C. Gry
P. Hennebelle
P. Hily-Blant
C. Joblin
R. Kolos
J. Krelowski
J. Martin-Pintado
K. Menten
Raquel Monje
M. Perault
R. Plume
M. Salez
S. Schlemmer
M. Schmidt
D. Teyssier
I. Peron
P. Cais
P. Gaufre
A. Cros
L. Ravera
Pasadena C. A. Anal
Large Atacama
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 521 1 Article Number: L45 - L45Subject Categories
Astronomy, Astrophysics and Cosmology
DOI
10.1051/0004-6361/201015105