scholarly journals Planetary nebulae in the inner Milky Way

2009 ◽  
Vol 5 (S265) ◽  
pp. 354-355
Author(s):  
Oscar Cavichia ◽  
Roberto D. D. Costa ◽  
Walter J. Maciel
Keyword(s):  
Statistical Analysis ◽  
Milky Way ◽  
Planetary Nebulae ◽  
Galactic Bulge ◽  
Intermediate Mass ◽  
Disk Interface ◽  
The Galaxy ◽  
Outer Border ◽  
Good Agreement

AbstractNew abundances of planetary nebulae located towards the bulge of the Galaxy are derived based on observations made at LNA (Brazil). We present accurate abundances of the elements He, N, S, O, Ar, and Ne for 56 PNe located towards the galactic bulge. The data shows a good agreement with other results in the literature, in the sense that the distribution of the abundances is similar to those works. From the statistical analysis performed, we can suggest a bulge-disk interface at 2.2 kpc for the intermediate mass population, marking therefore the outer border of the bulge and inner border of the disk.

scholarly journals Helium abundances in inner Galaxy planetary nebulae

2009 ◽  
Vol 5 (S268) ◽  
pp. 171-172
Author(s):  
Oscar Cavichia ◽  
Roberto D. D. Costa ◽  
Walter J. Maciel
Keyword(s):  
Galactic Center ◽  
Galactic Disk ◽  
Planetary Nebulae ◽  
Galactic Bulge ◽  
The Galaxy ◽  
Good Agreement

AbstractNew helium abundances of planetary nebulae located towards the bulge of the Galaxy were derived, based on observations made at OPD (Brazil). We present accurate helium abundances for 56 PNe located towards the galactic bulge. The data show good agreement with other results in the literature, in the sense that the distribution of the abundances is similar to previous works. Furthermore, the radial helium gradient is extended towards the galactic center. The results show that no trend can be identified when comparing the internal gradient (R ≤ 4 kpc) to the whole galactic disk.

scholarly journals Atomic Data and Neutron-Capture Element Abundances in Planetary Nebulae

2016 ◽  
Vol 12 (S323) ◽  
pp. 74-81
Author(s):  
N. C. Sterling
Keyword(s):  
Neutron Capture ◽  
Milky Way ◽  
Planetary Nebulae ◽  
Atomic Data ◽  
Experimental Investigations ◽  
Agb Stars ◽  
Intermediate Mass ◽  
Element Abundances ◽  
Nearby Galaxies

AbstractNeutron(n)-capture elements are produced by s-process nucleosynthesis in low- and intermediate-mass AGB stars, and therefore can be enriched in planetary nebulae (PNe). In the last ten years, n-capture elements have been detected in more than 100 PNe in the Milky Way and nearby galaxies. In some objects, several different n-capture elements have been detected, providing valuable constraints to models of AGB nucleosynthesis and evolution. These detections have motivated theoretical and experimental investigations of the atomic data needed to derive accurate n-capture element abundances. In this review, I discuss the methods and results of these atomic data studies, and their application to abundance determinations in PNe.

scholarly journals The nature of the Galactic bulge: A view from bulge planetary nebulae and globular clusters

2011 ◽  
Vol 7 (S283) ◽  
pp. 408-409
Author(s):  
Alexander F. Kholtygin ◽  
Yulia V. Milanova ◽  
Igor' I. Nikiforov ◽  
Olga V. Vasyakina
Keyword(s):  
Globular Clusters ◽  
Milky Way ◽  
Planetary Nebulae ◽  
Thin Disk ◽  
Type Ii ◽  
Galactic Bulge ◽  
Abundance Pattern ◽  
History Of ◽  
Disk Subsystem ◽  
Chemical History

AbstractModern data concerning the planetary nebulae (PNe) in the bulge, bar and disk of the Milky Way are used to study the chemical history of bulge. We show that the abundance pattern is similar for PNe in the bulge and Peimbert's type II PNe. We also found that the globular clusters (GCs), especially their metal-rich disk subsystem, form on metallicity maps a bar-like structure which parameters are very close to those for the Galactic bar. These results evidence an old age of the Galactic bulge and bar. We propose a scenario of the successive star formation in the bulge, bar and thin disk.

scholarly journals The Evolutionary History of the Milky Way

1996 ◽  
Vol 171 ◽  
pp. 3-10
Author(s):  
K.C. Freeman
Keyword(s):  
Evolutionary History ◽  
Milky Way ◽  
Dwarf Galaxy ◽  
Galactic Disk ◽  
Small Satellite ◽  
Galactic Bulge ◽  
The Galaxy ◽  
History Of ◽  
Satellite Galaxies

The accretion of small satellite galaxies appears to have been important in the formation of the metal-poor halo of the Galaxy. The disrupting Sgr dwarf galaxy and the recent discovery of a young, metal-poor component of the halo indicate that this is a continuing process. The evolution of the galactic disk, and some consequences of the bar-like nature of the galactic bulge are briefly discussed.

scholarly journals POPULATION OF BLACK HOLES IN THE MILKY WAY AND IN THE MAGELLANIC CLOUDS

2013 ◽  
Vol 53 (A) ◽  
pp. 665-670
Author(s):  
Janusz Ziółkowski
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Milky Way ◽  
Stellar Mass ◽  
Magellanic Clouds ◽  
Intermediate Mass ◽  
Different Types ◽  
The Galaxy

In this review, I will briefly discuss the different types of black hole (BH) populations (supermassive, intermediate mass and stellar mass BHs) both in the Galaxy and in the Magellanic Clouds and compare them with each other.

VVV Microlensing events in the far side of the Milky Way

2019 ◽  
Vol 14 (S353) ◽  
pp. 35-37
Author(s):  
María Gabriela Navarro ◽  
Dante Minniti ◽  
Rodrigo Contreras Ramos
Keyword(s):  
Milky Way ◽  
The Other ◽  
Line Of Sight ◽  
Galactic Bulge ◽  
Near Ir ◽  
The Galaxy ◽  
Different Populations ◽  
First Time

AbstractIn order to study the most reddened areas of the Milky Way we used near-IR data from the VVV Survey. For the first time, the VISTA telescope allows us to observe the mid-plane through the Galactic bulge and study the disk in the other side of the Milky Way. Motivated by the detection of hundreds of microlensing events in the inner regions of the Galaxy, we propose three new configurations of microlensing events, placing the sources in the far-disk and the lenses in the far-disk/bulge/near-disk. These new configurations will change the usual way to interpret the timescale distributions due to the different populations along the line of sight, that exhibit varied transverse velocities and relative distances.

scholarly journals The Galaxy and its stellar halo - insights from a hybrid cosmological approach

2008 ◽  
Vol 4 (S254) ◽  
pp. 423-428
Author(s):  
Gabriella De Lucia ◽  
Amina Helmi
Keyword(s):  
High Resolution ◽  
Physical Properties ◽  
Milky Way ◽  
Dynamical Friction ◽  
Milky Way Galaxy ◽  
The Galaxy ◽  
Stellar Halo ◽  
Good Agreement ◽  
Milky Way Halo

AbstractWe use a series of high-resolution N-body simulations of a ‘Milky-Way’ halo, coupled to semi-analytic techniques, to study the formation of our own Galaxy and of its stellar halo. Our model Milky Way galaxy is a relatively young system whose physical properties are in quite good agreement with observational determinations. In our model, the stellar halo is mainly formed from a few massive satellites accreted early on during the galaxy's lifetime. The stars in the halo do not exhibit any metallicity gradient, but higher metallicity stars are more centrally concentrated than stars with lower abundances. This is due to the fact that the most massive satellites contributing to the stellar halo are also more metal rich, and dynamical friction drags them closer to the inner regions of the host halo.

scholarly journals The Disc Origin of the Milky Way Bulge

2016 ◽  
Vol 33 ◽  
Author(s):  
P. Di Matteo
Keyword(s):  
Milky Way ◽  
Complex Structure ◽  
Galactic Bulge ◽  
Galactic Disc ◽  
Major Step ◽  
Thick Disc ◽  
Global Properties ◽  
Out Of Plane ◽  
The Galaxy ◽  
Main Components

AbstractThe Galactic bulge, that is the prominent out-of-plane over-density present in the inner few kiloparsecs of the Galaxy, is a complex structure, as the morphology, kinematics, chemistry, and ages of its stars indicate. To understand the nature of its main components—those at [Fe/H] ≳ −1 dex—it is necessary to make an inventory of the stellar populations of the Galactic disc(s), and of their borders: the chemistry of the disc at the solar vicinity, well known from detailed studies of stars over many years, is not representative of the whole disc. This finding, together with the recent revisions of the mass and sizes of the thin and thick discs, constitutes a major step in understanding the bulge complexity. N-body models of a boxy-/peanut-shaped bulge formed from a thin disc through the intermediary of a bar have been successful in interpreting a number of global properties of the Galactic bulge, but they fail in reproducing the detailed chemo-kinematic relations satisfied by its components and their morphology. It is only by adding the thick disc to the picture that we can understand the nature of the Galactic bulge.

scholarly journals Globular clusters and planetary nebulae kinematics and X-ray emission in the early-type galaxy NGC 5128

2006 ◽  
pp. 35-47 ◽  
Author(s):  
S. Samurovic
Keyword(s):  
Dark Matter ◽  
Total Mass ◽  
Globular Clusters ◽  
Planetary Nebulae ◽  
X Rays ◽  
X Ray ◽  
The Galaxy ◽  
The One ◽  
Early Type Galaxy ◽  
Good Agreement

The estimates of the mass of the galaxy NGC 5128 based on the different mass tracers, globular clusters (GCs) and planetary nebulae (PNe), are presented. These estimates are compared with the estimate based on the X-ray methodology and it is found that the results for the mass (and mass-to-light ratio) for all three approaches are in very good agreement interior to 25 arcmin; beyond 25 arcmin the X-rays predict the mass which is too high with respect to the one found using GCs and PNe. Some possible explanations for this discrepancy were discussed. The Jeans equation is also solved and its predictions for the velocity dispersion are then compared with the observed values, which extend to ~8 effective radii in the case of the GCs and ~15 effective radii in the case of the PNe. It is found that interior to ~25 arcmin (~5 effective radii) dark matter does not dominate because the total mass-to-light ratio in the B band in solar units is less than 10. Based on the GCs and PNe beyond ~25 arcmin the total mass-to-light ratio increases to ~14 (at ~80 arcmin) which indicates the existence of dark matter in the outer regions of NGC 5128.

scholarly journals The contribution of the Galactic Bulge to the Galactic rotation curve

1993 ◽  
Vol 153 ◽  
pp. 353-354
Author(s):  
I.V. Petrovskaya ◽  
S. Ninković
Keyword(s):  
Mass Distribution ◽  
Rotation Curve ◽  
Milky Way ◽  
Galactic Rotation ◽  
Galactic Bulge ◽  
Distinct Population ◽  
Gravitation Field ◽  
The Galaxy ◽  
Galactic Rotation Curve

It is not always clear what the bulge of the Galaxy is: a region close to the centre, a subsystem formed by a distinct population, or a mixture of populations but characterised by its own mass distribution. We consider the bulge of the Milky Way as a subsystem and thus contributing to the galactic gravitation field. We want to estimate the contribution of the galactic bulge to the rotation curve.

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