Pith. sign in

REVIEW 1 cited by

Herschel observations of extra-ordinary sources: Detecting spiral arm clouds by CH absorption lines

Not yet reviewed by Pith; the record is open.

Re-run · record.json Download PDF Read on arXiv ↗

This paper has not been read by Pith yet. Machine review is queued; the pith claim, tier, and objections will appear here once it completes.

SPECIMEN: schema-true, not a live event

T0 review · schema-true

One-sentence machine reading of the paper's core claim.

pith:XXXXXXXX · record.json · timestamp

arxiv 1007.1867 v1 pith:W6TSI6CM submitted 2010-07-12 astro-ph.GA

Herschel observations of extra-ordinary sources: Detecting spiral arm clouds by CH absorption lines

S.-L. Qin , P. Schilke , C. Comito , T. M\"oller , R. Rolffs , H.S.P. M\"uller , A. Belloche , K. M. Menten
show 62 more authors
D. C. Lis T.G. Phillips E. A. Bergin T. A. Bell N. R. Crockett G. A. Blake S. Cabrit E. Caux C. Ceccarelli J. Cernicharo F. Daniel M.-L. Dubernet M. Emprechtinger P. Encrenaz E. Falgarone M. Gerin T. F. Giesen J. R. Goicoechea P. F. Goldsmith H. Gupta E. Herbst C. Joblin D. Johnstone W. D. Langer S.D. Lord S. Maret P.G. Martin G.J. Melnick P. Morris J.A. Murphy D.A. Neufeld V. Ossenkopf L. Pagani J. C. Pearson M. P\'erault R. Plume M. Salez S. Schlemmer J. Stutzki N. Trappe F.F.S. van der Tak C. Vastel S. Wang H.W.Yorke S. Yu J. Zmuidzinas A. Boogert R. G\"usten P. Hartogh N. Honingh A. Karpov J. Kooi J.M. Krieg R. Schieder M.C. Diez-Gonzalez R. Bachille J. Martin-Pintado W. Baechtold M. Olberg L.H. Nordh J.L. Gill G. Chattopadhyay
This is my paper
classification astro-ph.GA
keywords cloudsabsorptioncolumnlineobservationsspiralclouddensity
verification ladder T0 review T1 audit T2 compute T3 formal T4 reserved
0 comments
read the original abstract

We have observed CH absorption lines ($J=3/2, N=1 \leftarrow J=1/2, N=1$) against the continuum source Sgr~B2(M) using the \textit{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 $A_V$ 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.

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Forward citations

Cited by 1 Pith paper

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score.

  1. Cosmic Rulers: Masers as Tools for Probing Structure in the Galaxy and Beyond, from AU to kpc

    astro-ph.GA 2026-06 unverdicted novelty 2.0

    Maser emissions act as cosmic rulers for astrometric measurements of astronomical sources from protostellar scales to galactic distances, with SKA-Mid enabling expanded multi-species observations.