The Widespread Occurrence of Water Vapor in the Circumstellar Envelopes of Carbon-Rich Asymptotic Giant Branch Stars: First Results From a Survey With Herschel/HIFI
Artikel i vetenskaplig tidskrift, 2011

We report the preliminary results of a survey for water vapor in a sample of eight C stars with large mid-IR continuum fluxes: V384 Per, CIT 6, V Hya, Y CVn, IRAS 15194-5115, V Cyg, S Cep, and IRC+40540. This survey, performed using the HIFI instrument on board the Herschel Space Observatory, entailed observations of the lowest transitions of both ortho-and para-water: the 556.936 GHz 1(10)-1(01) and 1113.343 GHz 1(11)-0(00) transitions, respectively. Water vapor was unequivocally detected in all eight of the target stars. Prior to this survey, IRC+10216 was the only carbon-rich asymptotic giant branch (AGB) star from which thermal water emissions had been discovered, in that case with the use of the Submillimeter Wave Astronomy Satellite (SWAS). Our results indicate that IRC+10216 is not unusual, except insofar as its proximity to Earth leads to a large line flux that was detectable with SWAS. The water spectral line widths are typically similar to those of CO rotational lines, arguing against the vaporization of a Kuiper Belt analog being the general explanation for water vapor in carbon-rich AGB stars. There is no apparent correlation between the ratio of the integrated water line fluxes to the 6.3 mu m continuum flux-a ratio which measures the water outflow rate-and the total mass-loss rate for the stars in our sample.

emission

mass-loss rates

discovery

submillimeter: stars

circumstellar matter

stars: abundances

spectra

winds

v-hydrae

lines

stars: AGB and post-AGB

outflow

irc+10216

chemistry

Författare

D. A. Neufeld

Johns Hopkins University

E. Gonzalez-Alfonso

Universidad de Alcala

G. J. Melnick

Harvard-Smithsonian Center for Astrophysics

R. Szczerba

Polish Academy of Sciences

M. Schmidt

Polish Academy of Sciences

L. Decin

Universiteit Van Amsterdam

KU Leuven

J. Alcolea

Observatorio Astronamico Nacional (OAN-IGN)

A. de Koter

Sterrekundig Instituut Utrecht

Universiteit Van Amsterdam

Fredrik Schöier

Chalmers, Rymd- och geovetenskap, Onsala rymdobservatorium

V. Bujarrabal

Observatorio Astronamico Nacional (OAN-IGN)

J. Cernicharo

Centro de Astrobiologia (CAB)

C. Dominik

Universiteit Van Amsterdam

Radboud Universiteit

Kay Justtanont

Chalmers, Rymd- och geovetenskap, Radioastronomi och astrofysik

A. P. Marston

European Space Astronomy Centre (ESA)

K. Menten

Max Planck-institutet

Hans Olofsson

Chalmers, Rymd- och geovetenskap, Onsala rymdobservatorium

P. Planesas

Observatorio Astronamico Nacional (OAN-IGN)

Atacama Large Millimeter-submillimeter Array (ALMA)

D. Teyssier

Centro de Astrobiologia (CAB)

Lbfm Waters

Netherlands Institute for Space Research (SRON)

Universiteit Van Amsterdam

Astrophysical Journal Letters

2041-8205 (ISSN) 2041-8213 (eISSN)

Vol. 727 2 L29

Ämneskategorier

Astronomi, astrofysik och kosmologi

DOI

10.1088/2041-8205/727/2/L29

Mer information

Senast uppdaterat

2018-10-30