The extended interacting wind structure of Eta Carinae

Gull, Theodore R.; Nielsen, K. E.; Corcoran, M. F.; Madura, Thomas; Owocki, Stan; Russell, Christopher M. P.; Hillier, D. J.; Hamaguchi, Kenji; Kober, Gladys V.; Weis, K.; Stahl, O.; Okazaki, Atsuo T.

doi:10.1111/j.1365-2966.2009.14854.x

Cited by 57 publications

(138 citation statements)

References 45 publications

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“…In the central binary system, the NW corresponds to the direction of apastron of the very eccentric orbit (Madura et al 2012;Gull et al 2009), where η Car's hot companion spends most of its time during the 5.5 yr cycle (see Figure 4). The opening of the colliding-wind shock cone therefore points in this direction most of the time.…”

Section: Near-ir H2 Emission and Kinematic Structurementioning

confidence: 99%

A disrupted molecular torus around Eta Carinae as seen in 12CO with ALMA

Smith

Ginsburg

Bally

2017

Monthly Notices of the Royal Astronomical Society

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We present Atacama Large Millimeter Array (ALMA) observations of 12 CO 2−1 emission from circumstellar material around the massive star η Carinae. These observations reveal new structural details about the cool equatorial torus located ∼4000 au from the star. The CO torus is not a complete azimuthal loop, but rather, is missing its near side, which appears to have been cleared away. The missing material matches the direction of apastron in the eccentric binary system, making it likely that η Car's companion played an important role in disrupting portions of the torus soon after ejection. Molecular gas seen in ALMA data aligns well with the cool dust around η Car previously observed in mid-infrared (IR) maps, whereas hot dust resides at the inner surface of the molecular torus. The CO also coincides with the spatial and velocity structure of near-IR H 2 emission. Together, these suggest that the CO torus seen by ALMA is actually the pinched waist of the Homunculus polar lobes, which glows brightly because it is close to the star and warmer than the poles. The near side of the torus appears to be a blowout, associated with fragmented equatorial ejecta. We discuss implications for the origin of various features northwest of the star. CO emission from the main torus implies a total gas mass in the range of 0.2 -1 M ⊙ (possibly up to 5 M ⊙ or more, although with questionable assumptions). Deeper observations are needed to constrain CO emission from the cool polar lobes.

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Section: Near-ir H2 Emission and Kinematic Structurementioning

confidence: 99%

A disrupted molecular torus around Eta Carinae as seen in 12CO with ALMA

Smith

Ginsburg

Bally

2017

Monthly Notices of the Royal Astronomical Society

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“…The wind collision leads to a wind-wind collision cavity (e.g., Pittard & Corcoran 2002;Humphreys et al 2008;Okazaki et al 2008;Parkin et al 2009Parkin et al , 2011Gull et al 2009Gull et al , 2011Madura & Owocki 2010;Madura et al 2012Madura et al , 2013Groh et al 2010Groh et al , 2012a. Radiative transfer models of the wind-wind collision zone were reported by Clementel et al (2015a,b).…”

Section: Introductionmentioning

confidence: 99%

“…Studies of the binary or binary wind-wind collision zone were reported by many authors (e.g., Damineli 1996;Damineli et al 1997Damineli et al , 1998Damineli et al , 2000Damineli et al , 2008bDavidson 1997;Davidson et al 2005Davidson et al , 2015Smith & Gehrz 2000;Smith et al 2004;Smith 2010;Pittard & Corcoran 2002;Corcoran et al 1997Corcoran et al , 2001Corcoran 2005;Ishibashi et al 1999;Soker 2003Soker , 2007Weis et al 2005;Gull et al 2006Gull et al , 2009Gull et al , 2011Gull et al , 2016Nielsen et al 2007;Weigelt et al 2007; Kashi & Soker 2007, 2009aParkin et al 2009;Groh et al 2010Groh et al , 2012bMadura & Owocki 2010;Madura et al 2012Madura et al , 2013Mehner et al 2010aMehner et al , 2011Mehner et al , 2012Mehner et al , 2015Richardson et al 2010;Teodoro et al 2013Teodoro et al , 2016Clementel et al 2015a,b;Hamaguchi et al 2016). The X-ray...…”

Section: Introductionmentioning

confidence: 99%

“…Detailed HST/STIS imaging of η Car with a resolution of about 0.1 allowed Gull et al (2009), Mehner et al (2010a, Teodoro et al (2013), and Gull et al (2016) to image the circumstellar environment of η Car across emission lines and at several orbital phases. The discovered structures are the result of the wind-wind collision over the past ∼20 yr.…”

Section: Introductionmentioning

confidence: 99%

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VLTI-AMBER velocity-resolved aperture-synthesis imaging ofηCarinae with a spectral resolution of 12 000

Weigelt

Hofmann

Schertl

et al. 2016

A&A

Self Cite

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Context. The mass loss from massive stars is not understood well. η Carinae is a unique object for studying the massive stellar wind during the luminous blue variable phase. It is also an eccentric binary with a period of 5.54 yr. The nature of both stars is uncertain, although we know from X-ray studies that there is a wind-wind collision whose properties change with orbital phase. Aims. We want to investigate the structure and kinematics of η Car's primary star wind and wind-wind collision zone with a high spatial resolution of ∼6 mas (∼14 au) and high spectral resolution of R = 12 000. Methods. Observations of η Car were carried out with the ESO Very Large Telescope Interferometer (VLTI) and the AMBER instrument between approximately five and seven months before the August 2014 periastron passage. Velocity-resolved aperture-synthesis images were reconstructed from the spectrally dispersed interferograms. Interferometric studies can provide information on the binary orbit, the primary wind, and the wind collision.Results. We present velocity-resolved aperture-synthesis images reconstructed in more than 100 different spectral channels distributed across the Brγ 2.166 µm emission line. The intensity distribution of the images strongly depends on wavelength. At wavelengths corresponding to radial velocities of approximately −140 to −376 km s −1 measured relative to line center, the intensity distribution has a fan-shaped structure. At the velocity of −277 km s −1 , the position angle of the symmetry axis of the fan is ∼126 • . The fan-shaped structure extends approximately 8.0 mas (∼18.8 au) to the southeast and 5.8 mas (∼13.6 au) to the northwest, measured along the symmetry axis at the 16% intensity contour. The shape of the intensity distributions suggests that the obtained images are the first direct images of the innermost wind-wind collision zone. Therefore, the observations provide velocity-dependent image structures that can be used to test three-dimensional hydrodynamical, radiative transfer models of the massive interacting winds of η Car.

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“…It has also been suggested that Argon be used as a metal abundance indicator for spectral diagnostics (Barker 1980). This intense line has been observed in the binary of η Carinae and used to model wind interaction within the system (Gull et al 2009). Specifically, there has been work adopting the line ratio (Ar iii λ7135Å)/(O iii λ5007Å) to determine Oxygen abundance in H ii and star forming regions (Stasińska 2006).…”

Section: Introductionmentioning

confidence: 99%

Valence and L-shell photoionization of Cl-like argon using R-matrix techniques

Tyndall

Ramsbottom

Ballance

et al. 2015

Mon. Not. R. Astron. Soc.

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Photoionization cross sections are obtained using the relativistic Dirac Atomic Rmatrix Codes (darc) for all valence and L-shell energy ranges between 27-270eV. A total of 557 levels arising from the dominant configurations 3s 2 3p 4 , 3s3p 5 , 3p 6 , 3s 2 3p 3 [3d, 4s, 4p], 3p 5 3d, 3s 2 3p 2 3d 2 , 3s3p 4 3d, 3s3p 3 3d 2 and 2s 2 2p 5 3s 2 3p 5 have been included in the target wavefunction representation of the Ar iii ion, including up to 4p in the orbital basis. We also performed a smaller Breit-Pauli (bp) calculation containing the lowest 124 levels. Direct comparisons are made with previous theoretical and experimental work for both valence shell and L-shell photoionization. Excellent agreement was found for transitions involving the 2 P o initial state to all allowed final states for both calculations across a range of photon energies. A number of resonant states have been identified to help analyze and explain the nature of the spectra at photon energies between 250 and 270eV.

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The extended interacting wind structure of Eta Carinae

Cited by 57 publications

References 45 publications

A disrupted molecular torus around Eta Carinae as seen in 12CO with ALMA

A disrupted molecular torus around Eta Carinae as seen in 12CO with ALMA

VLTI-AMBER velocity-resolved aperture-synthesis imaging ofηCarinae with a spectral resolution of 12 000

Valence and L-shell photoionization of Cl-like argon using R-matrix techniques

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