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相关论文: Chemical abundances of planetary nebulae in the di…

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The light distribution in the inner few kiloparsecs of the Milky Way is recovered non-parametrically from a dust-corrected near-infrared COBE/DIRBE surface brightness map of the inner Galaxy. The best fits to the photometry are obtained…

天体物理学 · 物理学 2015-06-24 James Binney , Ortwin Gerhard , David Spergel

The elemental abundance structure of the Galactic disc has been extensively studied in the solar neighbourhood using long-lived stars such as F and G dwarfs or K and M giants. These are stars whose atmospheres preserve the chemical…

星系天体物理 · 物理学 2015-05-18 T. Bensby , A. Alves-Brito , M. S. Oey , D. Yong , J. Meléndez

Chemical abundances of stars in the Milky Way disk are empirical tracers of its enrichment history. However, they capture joint-information that is valuable to disentangle. In this work, we seek to quantify how individual abundances evolve…

星系天体物理 · 物理学 2023-02-08 Bridget Ratcliffe , Melissa Ness

Stars in an open cluster are assumed to have formed from a broadly homogeneous distribution of gas, implying that they should be chemically homogeneous. Quantifying the level to which open clusters are chemically homogeneous can therefore…

星系天体物理 · 物理学 2024-09-05 Amaya Sinha , Gail Zasowski , Peter Frinchaboy , Katia Cunha , Diogo Souto , Jamie Tayar , Keivan Stassun

The Galactic bulge and bar are critical to our understanding of the Milky Way. However, due to the lack of reliable stellar distances, the structure and kinematics of the bulge/bar beyond the Galactic center have remained largely…

Electron temperatures, densities, ionic and elemental abundances of helium, nitrogen, oxygen, argon, sulfur and neon were derived for a sample of bulge planetary nebulae, representative of its intermediate mass population. Using these…

天体物理学 · 物理学 2009-11-13 Roberto D. D. Costa , Andre V. Escudero , Walter J. Maciel

We observed 64 newly identified galactic bulge planetary nebulae in the radio continuum at 3 and 6 cm with the Australia Telescope Compact Array. We present their radio images, positions, flux densities, and angular sizes. The survey…

天体物理学 · 物理学 2009-11-06 Griet C. Van de Steene , George H. Jacoby

We present a systematic study of line widths in the [\ion{O}{3}]$\lambda$5007 and H$\alpha$ lines for a sample of 86 planetary nebulae in the Milky Way bulge based upon spectroscopy obtained at the \facility{Observatorio Astron\'omico…

The determination of accurate chemical abundances of planetary nebulae (PN) in different galaxies allows us to obtain important constraints of chemical evolution models for these systems. We have a long term program to derive abundances in…

宇宙学与河外天体物理 · 物理学 2009-04-17 W. J. Maciel , R. D. D. Costa , T. E. P. Idiart

Previous studies of the chemo-kinematic properties of stars in the Galactic bulge have revealed a puzzling trend. Along the bulge minor axis, and close to the Galactic plane, metal-rich stars display a higher line-of-sight velocity…

We describe the motivation, field locations and stellar selection for the ARGOS spectroscopic survey of 28,000 stars in the bulge and inner disk of the Milky Way galaxy across latitudes of b = -5 deg to -10 deg. The primary goal of this…

星系天体物理 · 物理学 2012-12-10 K. Freeman , M. Ness , E. Wylie de Boer , E. Athanassoula , J. Bland Hawthorn , M. Asplund , G. Lewis , D. Yong , R. Lane , L. Kiss , R. Ibata

Although there have been numerous studies of chemical abundances in the Galactic bulge, the central two degrees have been relatively unexplored due to the heavy and variable interstellar extinction, extreme stellar crowding, and the…

星系天体物理 · 物理学 2019-07-17 M. Schultheis , R. M. Rich , L. Origlia , N. Ryde , G. Nandakumar , B. Thorsbro , N. Neumayer

This paper presents a homogeneous study of abundances in a sample of 79 northern galactic planetary nebulae whose morphological classes have been uniformly determined. Ionic abundances and plasma diagnostics were derived from selected…

天体物理学 · 物理学 2008-11-26 L. Stanghellini , A. M. Guerrero , K. Cunha , A. Manchado , E. Villaver

Some of the most successful statistical methods for obtaining distances of planetary nebulae (PNe) are based on their apparent sizes and radio emission intensities. These methods have the advantage of being "extinction-free" and are…

星系天体物理 · 物理学 2015-05-30 R. Ortiz , M. V. F. Copetti , S. Lorenz-Martins

In the central few degrees of the bulge of the Milky Way there is a flattened structure of gas, dust and stars (the central molecular zone) similar to nuclear disks in other galaxies. Due to extreme foreground extinction we possess only…

Planetary nebulae (PN) are an excellent laboratory to investigate the nucleosynthesis and chemical evolution of intermediate mass stars. In these objects accurate abundances can be obtained for several chemical elements that are…

太阳与恒星天体物理 · 物理学 2010-12-02 W. J. Maciel , R. D. D. Costa , T. E. P. Idiart

We have, for the first time, compiled a nearly complete census of planetary nebulae (PNe) centred on the Sun. Our goal is the generation of an unbiased volume-limited sample, in order to answer some long-standing statistical questions…

太阳与恒星天体物理 · 物理学 2010-10-26 David J. Frew , Quentin A. Parker

Evidence for a bar at the center of the Milky Way triggered a renewed enthusiasm for dynamical modelling of the Galactic bar-bulge. Our goal is to compare the kinematics of a sample of tracers, planetary nebulae, widely distributed over the…

天体物理学 · 物理学 2009-10-31 Sylvie F. Beaulieu , Kenneth C. Freeman , Agris J. Kalnajs , Prasenjit Saha , HongSheng Zhao

We present the metallicity results from the ARGOS spectroscopic survey of the Galactic bulge. Our aim is to understand the formation of the Galactic bulge: did it form via mergers, as expected from Lambda CDM theory, or from disk…

A major goal in the field of galaxy formation is to understand the formation of the Milky Way's disk. The first step toward doing this is to empirically describe its present state. We use the new high-dimensional dataset of 19 abundances…

星系天体物理 · 物理学 2020-02-19 Bridget L. Ratcliffe , Melissa K. Ness , Kathryn V. Johnston , Bodhisattva Sen