Multi-wavelength study of NGC 281 A

Henning, Th.; Martin, Katrin; Launhardt, R.; Reimann, H. G.

doi:10.1007/bfb0102175

Cited by 7 publications

(14 citation statements)

References 4 publications

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“…Similar to the Orion nebula, Sh 184 (NGC 281) harbours the young cluster IC 1590, which is dominated by the trapezium system HD 5005. The earliest‐type star of the trapezium, HD 5005AB, is either an O5.5f (Conti & Alschuler 1971), an O6.5 V((f)) (Walborn 1973) or an O6 III (Henning et al 1994); the other components are O8 V(n) and O9 V(n) (Guetter & Turner 1997). Sh 184 is associated with a molecular cloud, NGC 281A, which consists of two fragments (Henning et al 1994, and references therein).…”

Section: The Helium Abundancementioning

confidence: 99%

Oxygen and helium abundances in Galactic H II regions -- II. Abundance gradients

Deharveng¹,

Peña

Caplan³

et al. 2000

Monthly Notices of the Royal Astronomical Society

218

257

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The absolute integrated fluxes that we obtained (Paper I) for 34 H ii regions, with Galactocentric distances RG in the 6.6–17.7 kpc range, in the emission lines [O ii] λλ3726 and 3729, [O iii] λλ4363 and 5007, He iλ5876, Hα and Hβ, are analysed to derive the extinctions, the electron densities and temperatures, the ionic abundances O+/H+, O++/H+ and He+/H+ and the O/H abundances. The electron temperature has been derived from the [O iii] λ4363/λ5007 ratio in six H ii regions with RG between 6.6 and 14.8 kpc. These new measurements of Te, which are in good agreement with those from radio recombination lines, widen the RG range for which reliable Te measurements exist. Combining our new Te([O iii]) results with the radio values, we obtain the following temperature relationship: TeK]=(372±38)RG+4260±350. The O+/H+ and O++/H+ abundances have been obtained assuming a two‐temperature H ii region model. Our O/H relationship for 5 kpc

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Section: The Helium Abundancementioning

confidence: 99%

Oxygen and helium abundances in Galactic H II regions -- II. Abundance gradients

Deharveng¹,

Peña

Caplan³

et al. 2000

Monthly Notices of the Royal Astronomical Society

218

257

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“…It impacts the synthesis of complex organic molecules in molecular clouds, the wind-driving of evolved stars and the formation of celestial bodies (e.g. asteroids, planets) in protoplanetary discs Henning (2010). Asymptotic Giant Branch (AGB) stars represent a major contributor to the global dust budget in galaxies.…”

Section: Overviewmentioning

confidence: 99%

From molecules to dust grains: The role of alumina cluster seeds

et al. 2019

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Asymptotic Giant Branch (AGB) stars contribute a major part to the global dust budget in galaxies. Owing to their refractory nature alumina (stoichiometric formula AlO) is a promising candidate to be the first condensate emerging in the atmospheres of oxygen-rich AGB stars. Strong evidence for that is supplied by the presence of alumina in pristine meteorites and a broad spectral feature observed around ∼ 13 μm. The emergence of a specific condensate depends on the thermal stability of the solid, the gas density and its composition. The evaluation of the condensates is based on macroscopic bulk properties. The growth and size distribution of dust grains is commonly described by Classical Nucleation Theory (CNT). We question the applicability of CNT in an expanding circumstellar envelope as CNT presumes thermodynamic equilibrium and requires, in practise, seed nuclei on which material can condense. However, nano-sized molecular clusters differ significantly from bulk analogues. Quantum effects of the clusters lead to non-crystalline structures, whose characteristics (energy, geometry) differ substantially, compared to the bulk material. Hence, a kinetic quantum-chemical treatment involving various transition states describes dust nucleation most accurately. However, such a treatment is prohibitive for systems with more than 10 atoms. We discuss the viability of chemical-kinetic routes towards the formation of the monomer (Al2O3) and the dimer (Al4O6) of alumina.

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“…If we adopt an estimated distance of 2.2 kpc (Georgelin & Georgelin 1976;Roger & Pedlar 1981) or 3.5 kpc (Henning et al 1994) instead of 2.9 kpc in the parallax subtraction, the resultant mean proper motions of C3 and C1 vary only by 10−15%.…”

Section: Absolute Positions and Absolute Proper Motionsmentioning

confidence: 99%

“…The NGC 281 nebula is an H II region surrounded by a giant molecular cloud complex which was entirely mapped in the CO emission line by Lee and Jung (2003). The determination of the photometric/kinematic distance to the NGC 281 region has been attempted for many years, but the obtained values vary widely from 2 kpc to 3.5 kpc (e.g., Sharpless 1954;Georgelin & Georgelin 1976;Roger & Pedlar 1981;Henning et al 1994;Guetter & Turner 1997;Lee & Jung 2003). The source of ionization for the NGC 281 nebula is a star cluster whose brightest member is a compact, Trapezium-like OB multiple star system called ADS 719 or HD 5005 (Sharpless 1954;Elmegreen & Lada 1978;Henning et al 1994;Guetter & Turner 1997).…”

Section: Introductionmentioning

confidence: 99%

“…The determination of the photometric/kinematic distance to the NGC 281 region has been attempted for many years, but the obtained values vary widely from 2 kpc to 3.5 kpc (e.g., Sharpless 1954;Georgelin & Georgelin 1976;Roger & Pedlar 1981;Henning et al 1994;Guetter & Turner 1997;Lee & Jung 2003). The source of ionization for the NGC 281 nebula is a star cluster whose brightest member is a compact, Trapezium-like OB multiple star system called ADS 719 or HD 5005 (Sharpless 1954;Elmegreen & Lada 1978;Henning et al 1994;Guetter & Turner 1997). A southwestward proper motion of HD 5005 was observed with Hipparcos (Perryman et al 1997), but with insufficient precision to discuss the motion of the system.…”

Section: Introductionmentioning

confidence: 99%

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Absolute Proper Motions of H2O Masers Away from the Galactic Plane Measured with VERA in the “Superbubble” Region NGC 281

Sato¹,

Hirota²,

Honma³

et al. 2007

Publications of the Astronomical Society of Japan

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We report on absolute proper-motion measurements of an H 2 O maser source in the NGC 281 West molecular cloud, which is located ∼320 pc above the Galactic plane and is associated with an H I loop extending from the Galactic plane. We have conducted multi-epoch phase-referencing observations of the maser source with VERA (VLBI Exploration of Radio Astrometry) over a monitoring period of 6 months since May 2006. We find that the H 2 O maser features in NGC 281 West are systematically moving toward the southwest and further away from the Galactic plane with a vertical velocity of ∼20−30 km s −1 at its estimated distance of 2.2−3.5 kpc. Our new results provide the most direct evidence that the gas in the NGC 281 region on the H I loop was blown out from the Galactic plane, most likely in a superbubble driven by multiple or sequential supernova explosions in the Galactic plane.

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Multi-wavelength study of NGC 281 A

Cited by 7 publications

References 4 publications

Oxygen and helium abundances in Galactic H II regions -- II. Abundance gradients

Oxygen and helium abundances in Galactic H II regions -- II. Abundance gradients

From molecules to dust grains: The role of alumina cluster seeds

Absolute Proper Motions of H2O Masers Away from the Galactic Plane Measured with VERA in the “Superbubble” Region NGC 281

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