DETECTION OF VIBRATIONALLY EXCITED CO IN IRC+10216

Using the Submillimeter Array we have detected the J = 3–2 and 2–1 rotational transitions from within the first vibrationally excited state of CO toward the extreme carbon star IRC+10216 (CW Leo). The emission remains spatially unresolved with an angular resolution of ∼2″ and, given that the lines originate from energy levels that are ∼3100 K above the ground state, almost certainly originates from a much smaller (∼1014 cm) sized region close to the stellar photosphere. Thermal excitation of the lines requires a gas density of ∼109 cm−3, about an order of magnitude higher than the expected gas density based on previous infrared observations and models of the inner dust shell of IRC+10216.

[1]  S. Deguchi.  SiO maser survey of evolved stars in the Galaxy: various environments of maser sources , 2007, Proceedings of the International Astronomical Union.

[2]  R. Tibshirani,et al.  (37) Medications as Independent Risk Factors of Delirium in Patients With COVID-19: A Retrospective Study , 2018, Journal of the Academy of Consultation-Liaison Psychiatry.

[3]  K. Menten,et al.  Submillimeter vibrationally excited water emission from the peculiar red supergiant VY Canis Majoris , 2006, astro-ph/0606057.

[4]  K. Menten,et al.  Radio continuum monitoring of the extreme carbon star IRC+10216 , 2006, astro-ph/0603586.

[5]  P. Ffolliott,et al.  A Retrospective View , 2002 .

[6]  James M. Moran,et al.  The Submillimeter Array , 2004, Astronomical Telescopes and Instrumentation.

[7]  K. Menten,et al.  Physical Parameters of the IRC +10216 Circumstellar Envelope: New Constraints from Submillimeter Observations , 1997 .

[8]  P. J. Teuben,et al.  A retrospective view of Miriad , 1995 .

[9]  K. Menten,et al.  Discovery of Strong Vibrationally Excited Water Masers at 658 GHz toward Evolved Stars , 1995 .

[10]  Fionn Murtagh,et al.  In Astronomical Data Analysis Software and Systems IV , 1995 .

[11]  C. Townes,et al.  Characteristics of dust shells around 13 late-type stars. , 1994 .

[12]  J. Cernicharo,et al.  High-excitation SiO maser emission in VY Canis Majoris : detection of the v = 4 J = 5-4 transition , 1993 .

[13]  T. L. Wilson,et al.  Tools of Radio Astronomy , 1986 .

[14]  P. Wannier,et al.  CO 4.6 micron emission lines from the IRC +10216 inner envelope , 1985 .

[15]  P. Goldsmith,et al.  Infrared pumping and rotational excitation of molecules in interstellar clouds , 1981 .

[16]  M. Morris,et al.  On C4H versus vibrationally excited CO in IRC + 10216 , 1980 .

[17]  P. Thaddeus,et al.  Detection of the C4H radical toward IRC plus 10216 , 1978 .

[18]  N. Scoville,et al.  Vibrationally excited carbon monoxide in IRC+10216 , 1978 .

[19]  N. Scoville,et al.  Radiative trapping and population inversions of the SiO masers , 1974 .

[20]  D. Buhl,et al.  Detection of possible maser emission near 3.48 millimeters from an unidentified molecular species in Orion , 1974 .

[21]  E. Becklin,et al.  Infrared diameter of IRC + 10216 determined from lunar occultations. , 1972 .

[22]  Nicholas Chapman,et al.  Microwave Spectroscopy , 1955, Nature.