The - Line Velocity Field in M82

Heckathorn, H. M.

doi:10.1086/151441

Cited by 18 publications

(9 citation statements)

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“…We agree with the other investigators that the visible outflow at the SE side has to a large extent the geometry of a cone; however, contrary to SBH-98 and in agreement with our earlier observation (M-95) we find that the outflow at the NW side is also Lynds & Sandage (1963) "closed loops" (Ω = 120) (2) Burbidge et al (1964) Ω ≈ 20 pointed (3) Deharveng & Pellet (1970) "loop" 30; 300 (4) Heckathorn (1972) cone pointed (5) Axon & Taylor (1978) cone (6) Bland & Tully (1988) "bubbles" pointed (7) Heckman et al (1990) Ω SE = Ω NW = 62 pointed (8) Götz et al (1990 cone-like. The parameters of the adopted best-fit cone model as derived from the presented observation are summarized in Table 2; the correspondingly calculated velocity branches I-IV for the slit along the minor axis, or parallel to the minor axis (θ = ±20 ), are shown in Fig.…”

Section: The Adopted Model Of the Outflowsupporting

confidence: 90%

“…Detection at visible wavelengths of rotation of cone wall material at large distances from the disk was mentioned by Bland & Tully and Shopbell & Bland-Hawthorn. Spectra taken by Heckathorn (1972) parallel to the major axis to a distance of 675 pc below and 410 pc above the galactic plane have sloped tracks in the positionvelocity diagrams and by this clearly illustrate rotation of the visible outflow material, in the same direction as the material of the disk and with decreasing velocity for increasing distances from the disk. These and other imaging and spectroscopic observations were used to determine the geometry and kinematics of the visible outflow material; for a recent analysis and summary see SBH-98 and Table 1.…”

Section: Introductionmentioning

confidence: 70%

“…The spectra taken by Heckathorn (1972) parallel to the major axis to a distance Z ≤ 675 pc above and below the disk have sloped tracks in the corresponding p-v diagrams (his Figs. 2-17) and by this provide evidence of rotation of the visible cone wall material.…”

Section: Optical Observations (Filaments) Above the Diskmentioning

confidence: 99%

“…Radio data based on the CO observations by Sofue et al (1992) and Loiseau et al (1990): triangles; based on CO observations by Seaquist & Clark (2001): dots; based on CO observations by Walter et al (2002): squares. Optical data based on Hα, [NII] and [SII] slit spectra parallel to the major axis by Heckathorn (1972): open circles; this paper: shaded circles. The lines represent the parameter γ calculated for outflow with angular momentum conservation L vis of cone wall gas with Ω = 25…”

Section: Radio Observations (Co) Above the Diskmentioning

confidence: 99%

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The rotating visible outflow in M 82

Greve

2004

A&A

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Abstract. M 82's minor axis outflow is seen at visible wavelengths as more or less regular hollow cones on both sides of the galactic disk. The outflowing material is expected to entrain the rotation, or part of the rotation, of the disk where the outflow originates. From the conservation of angular momentum it is furthermore expected that the outflowing material continues to rotate at large distances from the disk, although probably with smaller velocity because of radial divergence of the cones. We provide evidence of this kinematic picture from long-slit spectra of the cone wall H α , [NII] and [SII] emission lines taken at ±20 (±300 pc) and ∼±40 (∼±600 pc) distance from the center and parallel to the minor axis, from data extracted from the literature, and from a cone model fit of the data. The angular momentum which is entrained in the outflow and eventually dissipated is a small fraction of the total angular momentum associated with the stars and gas in the central part of the disk. We compare our observation of the visible outflow with the outflow of dragged-out material investigated in mm-wavelength CO by other observers. It seems that the material observed at visible wavelengths is confined to narrow cones, and blows out at velocities larger than the escape velocity of the galaxy. The dragged-out material moves at slower velocities and on wider cones, and may fall back into the galaxy.

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Section: The Adopted Model Of the Outflowsupporting

confidence: 90%

Section: Introductionmentioning

confidence: 70%

Section: Optical Observations (Filaments) Above the Diskmentioning

confidence: 99%

Section: Radio Observations (Co) Above the Diskmentioning

confidence: 99%

See 2 more Smart Citations

The rotating visible outflow in M 82

Greve

2004

A&A

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“…Burbidge et al 1964;Heckathorn 1972;O'Connell & Mangano 1978;Götz et al 1990;McK93, Westmoquette et al 2009), a major axis p-v diagram is obtained as shown in the Figs. 1c, 2, and 3.…”

Section: The Stellar Disk-spiral Arm Model and Inconsistenciesmentioning

confidence: 89%

The apparent “reversed” motion of gas and stars in M 82

Greve

2011

A&A

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We summarize earlier and unpublished long-slit spectroscopic measurements of radial velocities of ionized gas and stars along and parallel to M 82's major axis to a radial distance of ∼±2.5 kpc (∼±140 ) from the center. In the position-velocity diagram, these measurements indicate a velocity reversal of ∼100 km s −1 of gas and/or stars at ∼±1.0 kpc (∼±50−70 ) on either side of the center, outside the bar. Although seen in earlier observations, and perhaps neglected because they were assumed to be only an effect of heavy local extinction, the positional symmetry of the velocity reversal with respect to the center of M 82, as well as the absence of the reversal in the motion of stars seen in the near-IR Ca ii absorption lines, points to another origin. M 82's two-armed spiral, as outlined by Mayya et al. (2005, ApJ, 628, L33), may explain a part of the velocity reversal, although this interpretation leaves inconsistencies so that other explanations must also be investigated. A simple, conclusive explanation of the velocity reversal has not yet been found. While restricted observationally in radial distance to ∼120 (2 kpc), the near-IR stellar Ca ii absorption lines, which do not show the velocity reversal, indicate a flat radial velocity curve of the stellar disk that remained after the encounter with M 81.

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The Central Regions of M82 – Scattered Light and Extinction

Notni

Bronkalla

1984

Astron Nachr

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Photographic photometric measurements of z arcsec resolution of the central regions of M82 are presented in the three colours U , B, V. The observed light is decomposed into two parts: stellar light and light from the central source scattered by dust. The tariation of the reddening of both components is derived.The dust distribution pattern is different near the spatial centre of M82 and farther out. The equator of the dust complex obscuring the central source is inclined to the overall symmetry plane of M82. The outer dust clouds responsible for the obscuration of the visible stellar light are probably arranged in a spiral-like fashion; the "plane" containing these clouds is strongly warped and disturbed.The light of the bright knots A and C consists to a considerable part of scattered light from the central source nearly behind them. Ha light and scattered continuum light is strongly correlated in M82, pointing to an ionisation of the gas by the source of this continuum in addition to the presence of scattered Ha.Photographische Helligkeitsmessungen des Zentralgebietes von M82 in U , B und V mit einer Auflosung von 2 " werden mitgeteilt. Die gemessene Lichtintensitat wird in die Anteile ,,Sternlicht" und ,,Streulicht der zentralen Quelle" zerlegt. Fiir beide Komponenten wird die Verfarbung abgeleitet.Die Verteilung des Staubes in M82 ist verschieden in den inneren und den PuBeren Gebieten. Der Aquator des mit der zentralen Quelle verbundenen Staubkomplexes ist gegen die auBere Symmetrieebene von M82 geneigt. Die auL3en-liegenden Staubwolken, die fur die Extinktion des sichtbaren Sternlichtes verantwortlich sind, sind vermutlich spiralahnlich angeordnet; die durch diese Wolken definierte ,,Ebene" ist stark verbogen und gestort.Das Licht der hellen zentralen Knoten A und C ist zu einem wesentlichen Teil Streulicht der zentralen Quelle, die versteckt fast hinter ihnen steht. Die Verteilung von Ha-Licht und kontinuierlichem Streulicht ist iiberall in M82 eng korelliert; der Anteil an Ha, der nzcht Streulicht ist, muD deshalb aus Gas stammen, das von der zentralen Quelle ionisiert wurde.

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The - Line Velocity Field in M82

Cited by 18 publications

References 0 publications

The rotating visible outflow in M 82

The rotating visible outflow in M 82

The apparent “reversed” motion of gas and stars in M 82

The Central Regions of M82 – Scattered Light and Extinction

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