Detection of OH toward the Extreme Carbon Star IRC +10216

  title={Detection of OH toward the Extreme Carbon Star IRC +10216},
  author={K. E. S. Ford and David A. Neufeld and Paul. F. Goldsmith and Gary J. Melnick},
  journal={The Astrophysical Journal},
We report the detection of the 1665 and 1667 MHz main lines of OH (hydroxyl) and upper limits on the 1612 MHz satellite line of OH toward the carbon-rich AGB star IRC +10216. We find a beam-averaged fractional abundance x(OH) ~ 4 × 10-8. This detection supports the identification by Melnick et al. of the 110-101 transition of water vapor with a 556.936 GHz rest-frequency emission feature detected toward IRC +10216, since OH is the expected photodissociation product of water vapor. The shape of… 

Figures and Tables from this paper

Detection of Formaldehyde toward the Extreme Carbon Star IRC +10216*
We report the detection of H2CO (formaldehyde) around the carbon-rich asymptotic giant branch star IRC +10216. We find a fractional abundance with respect to molecular hydrogen of x(H2CO) = 1.3 ×
Observations of the Circumstellar Water 110-->101 and Ammonia 10-->00 Lines in IRC +10216 by the Odin Satellite
Submillimeter lines of H2O and NH3 have been detected in the carbon star IRC +10216 (CW Leo) with the Odin submillimeter satellite. The detection of the J = 110 → 101 557 GHz line of ortho-H2O
Detection of C3O in IRC +10216: Oxygen-Carbon Chain Chemistry in the Outer Envelope
The oxygen-bearing species C3O has been identified in the circumstellar envelope of the carbon star IRC 10216. The , , , , and transitions were detected at 2 and 3 mm using the Arizona J p 8 r 79 r
Water vapor emission from IRC +10216 and other carbon-rich stars : Model predictions and prospects for multitransition observations
We have modeled the emission of H2O rotational lines from the extreme C-rich star IRC +10216. Our treatment of the excitation of H2O emissions takes into account the excitation of H2O both through
Herschel/HIFI Observations of IRC+10216: Water Vapor in the Inner Envelope of a Carbon-rich Asymptotic Giant Branch Star
We report the results of observations of 10 rotational transitions of water vapor toward the carbon-rich asymptotic giant branch (AGB) star IRC+10216 (CW Leonis), carried out with Herschel's HIFI
Oxygen chemistry in the circumstellar envelope of the carbon-rich star IRC+10216
In this paper we study the oxygen chemistry in the C-rich circumstellar shells of IRC +10216. The recent discoveries of oxygen-bearing species (water, hydroxyl radical, and formaldehyde) toward this
Detection of C3O in the Low-Mass Protostar Elias 18
We have performed new laboratory experiments which gave us the possibility to obtain an estimate of the amount of carbon chain oxides (namely C3O2, C2O, and C3O) formed after irradiation (with 200
A spectral-line survey of IRC+10216 in the 345 GHz band has been undertaken with the Submillimeter Array. Although not yet completed, it has already yielded a fairly large sample of narrow molecular
Constraints on the H2O formation mechanism in the wind of carbon-rich AGB stars
Context. The recent detection of warm H$_2$O vapor emission from the outflows of carbon-rich asymptotic giant branch (AGB) stars challenges the current understanding of circumstellar chemistry. Two
Detection of 4765 MHz OH Emission in a Preplanetary Nebula: CRL 618
Jets and outflows are ubiquitous phenomena in astrophysics, found in our Galaxy in diverse environments, from the formation of stars to late-type stellar objects. We present observations conducted


A λ2 mm molecular line survey of the C-star envelope IRC+10216
The mm-wave spectrum of the C-star envelope IRC+10216 has been continuously surveyed between 129.0 and 172.5 GHz with the IRAM 30-m telescope. 380 lines are detected, of which 317 have been identied.
An upper limit to the hydroxyl abundance in the circumstellar envelope of IRC + 10216
Thermal OH emission from IRC + 10216 in the 1665- and 1667-MHz lines has been searched for. No emission was detected, yielding an upper limit for the OH abundance in the envelope. Within the
The dust around the carbon star IRC +10216
Mass loss from late-type stars is important both in the evolution of these objects and for replenishment of the interstellar medium with processed material. Because the outflows are cool and dense,
Discovery of Multiple Molecular Shells in the Outer Envelope of IRC +10216
We present 12CO J = 1 → 0 maps of the extended envelope of IRC +10216 made by combining BIMA millimeter array and NRAO 12 m telescope observations. CO emission was detected beyond the radius of
Smoke Signals from IRC +10216. I. Milliarcsecond Proper Motions of the Dust
The results of a seven epoch interferometric imaging study, at wavelengths in the near-infrared K band, of the carbon star IRC+10216 are presented. The use of non- and partially redundant aperture
Discovery of water vapour around IRC+10216 as evidence for comets orbiting another star
The observation of circumstellar water vapour around the ageing carbon star IRC+10216 is reported; water is not expected in measurable quantities around such a star; the only plausible explanation for this water is that the recent evolution of IRC+ 10216 is causing the vaporization of a collection of orbiting icy bodies.
Water Vapor in Carbon-rich Asymptotic Giant Branch Stars from the Vaporization of Icy Orbiting Bodies
We argue that the presence of water vapor in the circumstellar outflow of a carbon-rich asymptotic giant branch (AGB) star is potentially a distinctive signature of extrasolar cometary systems.
Monitoring of long term behaviour of OH masers in semiregular variables: R Crt, W Hya and RT Vir ?
We present and interpret the results of a long-term OH variability study of three semiregular stars, one type a (SRa), W Hya, and two type b (SRb), R Crt and RT Vir. The 1665 and 1667 MHz OH masers
U Orionis: the evolution and proper motion of the OH maser envelope
The Jodrell Bank MERLIN array is used to map the OH 1665- and 1667-MHz masers in the circumstellar envelope of U Orionis in 1984, 1986 and 1987. The OH masers lie within a region of extended 130 ×
IRC+10 216 in action: Present episode of intense mass-loss reconstructed by two-dimensional radiative transfer modeling
M 3 10 4 M yr 1 in 2001. The rapid increase of the mass loss of IRC+10 216 and continuing time-dependent dust formation and destruction caused the observed displacement of the initially faint