Carbon monoxide emission from stars in the IRAS and revised AFGL catalogs. I - Mass loss driven by radiation pressure on dust grains

Zuckerman, B.; Dyck, H. M.

doi:10.1086/164173

Cited by 57 publications

(25 citation statements)

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“…From the modeling of the IR energy distribution done in Paper I, the mass loss rate was found as 1 × 10 −5 M yr −1 for a distance of 1500 pc assuming a gas-to-dust ratio of 100. Using the CO (2-1) line observations of Zuckerman & Dyck (1986), Loup et al (1993) estimate 5.2 × 10 −6 M yr −1 for d = 880 pc, whereas the modeling of the same line by Kastner (1990) gives 3.7 × 10 −6 M yr −1 for d = 840 pc. From CO (3-2) line observations, Knapp et al (1998) (Table 2).…”

Section: The Observational Datamentioning

confidence: 99%

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Self-consistent modeling of the outflow from the O-rich Mira IRC –20197

Jeong

Winters

Bertre

et al. 2003

A&A

123

159

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Abstract.We present a self-consistent time-dependent model for the oxygen-rich Mira variable IRC -20197. This model includes a consistent treatment of the interactions among hydrodynamics, thermodynamics, radiative transfer, equilibrium chemistry, and heterogeneous dust formation with TiO 2 nuclei. The model is determined by the stellar parameters, stellar mass4 L , stellar temperature T = 2400 K, and solar abundances of the elements. The pulsation of the star is simulated by a piston at the inner boundary where the velocity varies sinusoidally with a period of P = 636 d and an amplitude of ∆v p = 8 km s −1 . Based on the atmospheric structure resulting from this hydrodynamic calculation at different phases, we have performed angle-and frequency-dependent continuum radiation transfer calculations, which result in the spectral energy distributions at different phases of the pulsation cycle and in synthetic light curves at different wavelengths. These are in good agreement with the infrared observations of IRC -20197. The model yields a time averaged outflow velocity of 11.9 km s −1 and an average mass loss rate of 7.3 × 10 −6 M yr −1 which are in good agreement with the values derived from radio observations. Furthermore, the chemical composition of the resulting grains is discussed.

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Section: The Observational Datamentioning

confidence: 99%

“…The CO lines 7.2 × 10 −6 * K90 (Kastner 1990), LL93 (Le Sidaner & Le Bertre 1993), LFOP93 (Loup et al 1993), KYLJ98 (Knapp et al 1998), LW98 (Le Bertre & Winters 1998). indicate molecular gas expanding at a velocity of ∼14 km s −1 (Zuckerman & Dyck 1986;Knapp et al 1998).…”

Section: The Observational Datamentioning

confidence: 99%

Self-consistent modeling of the outflow from the O-rich Mira IRC –20197

Jeong

Winters

Bertre

et al. 2003

A&A

123

159

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“…The values for the f H,CO were chosen to be 1 × 10 −4 for O-rich stars (Kahane & Jura 1994), 3 × 10 −4 for S-type stars (Ramstedt et al 2006), and 5 × 10 −4 for C-rich stars (Zuckerman & Dyck 1986). All computations were performed for a 15 m class telescope, with beam sizes of 10 , 20 and 30 as grid input values.…”

Section: Description Of the Gridmentioning

confidence: 99%

Probing the mass-loss history of AGB and red supergiant stars from CO rotational line profiles

Beck

Decin

Koter

et al. 2010

A&A

240

281

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Context. The evolution of intermediate and low-mass stars on the asymptotic giant branch is dominated by their strong dust-driven winds. More massive stars evolve into red supergiants with a similar envelope structure and strong wind. These stellar winds are a prime source for the chemical enrichment of the interstellar medium. Aims. We aim to (1) set up simple and general analytical expressions to estimate mass-loss rates of evolved stars, and (2) from those calculate estimates for the mass-loss rates of the asymptotic giant branch, red supergiant, and yellow hypergiant stars in our galactic sample. Methods. The rotationally excited lines of carbon monoxide (CO) are a classic and very robust diagnostic in the study of circumstellar envelopes. When sampling different layers of the circumstellar envelope, observations of these molecular lines lead to detailed profiles of kinetic temperature, expansion velocity, and density. A state-of-the-art, nonlocal thermal equilibrium, and co-moving frame radiative transfer code that predicts CO line intensities in the circumstellar envelopes of late-type stars is used in deriving relations between stellar and molecular-line parameters, on the one hand, and mass-loss rate, on the other. These expressions are applied to our extensive CO data set to estimate the mass-loss rates of 47 sample stars. Results. We present analytical expressions for estimating the mass-loss rates of evolved stellar objects for 8 rotational transitions of the CO molecule and thencompare our results to those of previous studies. Our expressions account for line saturation and resolving of the envelope, thereby allowing accurate determination of very high mass-loss rates. We argue that, for estimates based on a single rotational line, the CO(2-1) transition provides the most reliable mass-loss rate. The mass-loss rates calculated for the asympotic giant branch stars range from 4 × 10 −8 M yr −1 up to 8 × 10 −5 M yr −1 . For red supergiants they reach values between 2 × 10 −7 M yr −1 and 3 × 10 −4 M yr −1 . The estimates for the set of CO transitions allow time variability to be identified in the mass-loss rate. Possible mass-loss-rate variability is traced for 7 of the sample stars. We find a clear relation between the pulsation periods of the asympotic giant branch stars and their derived mass-loss rates, with a levelling off at ∼3 × 10 −5 M yr −1 for periods exceeding 850 days. Conclusions.

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“…Linelists and References. (a) González-Alfonso et al (2007), (b) Zuckerman & Dyck (1986), (c) Crosas & Menten (1997), (d) Ridgway & Keady (1988). (available) collisional rates are described in Decin et al (2010).…”

Section: Abundance Profiles Of Sio and Sismentioning

confidence: 99%

Silicon in the dust formation zone of IRC +10216

Decin

Cernicharo

Barlow

et al. 2010

A&A

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The interstellar medium is enriched primarily by matter ejected from evolved low and intermediate mass stars. The outflows from these stars create a circumstellar envelope in which a rich gas-phase and dust-nucleation chemistry takes place. We observed the nearest carbon-rich evolved star, IRC +10216, using the PACS (55−210 μm) and SPIRE (194−672 μm) spectrometers on board Herschel. We find several tens of lines from SiS and SiO, including lines from the v = 1 vibrational level. For SiS these transitions range up to J = 124−123, corresponding to energies around 6700 K, while the highest detectable transition is J = 90−89 for SiO, which corresponds to an energy around 8400 K. Both species trace the dust formation zone of IRC +10216, and the broad energy ranges involved in their detected transitions permit us to derive the physical properties of the gas and the particular zone in which each species has been formed. This allows us to check the accuracy of chemical thermodynamical equilibrium models and the suggested depletion of SiS and SiO due to accretion onto dust grains.

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Carbon monoxide emission from stars in the IRAS and revised AFGL catalogs. I - Mass loss driven by radiation pressure on dust grains

Cited by 57 publications

References 0 publications

Self-consistent modeling of the outflow from the O-rich Mira IRC –20197

Self-consistent modeling of the outflow from the O-rich Mira IRC –20197

Probing the mass-loss history of AGB and red supergiant stars from CO rotational line profiles

Silicon in the dust formation zone of IRC +10216

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