scholarly journals Spectroscopy of new Planetary Nebulae close to the galactic center

1997 ◽  
Vol 180 ◽  
pp. 414-414
Author(s):  
G.C. Van de Steene ◽  
G. H. Jacoby
Keyword(s):  
Emission Line ◽  
Galactic Center ◽  
Planetary Nebulae ◽  
Chemical Enrichment ◽  
The Galaxy ◽  
History Of ◽  
Bright Emission ◽  
Bright Emission Line

Planetary Nebulae (PN) are bright emission line objects, observable at large distances throughout the Galaxy. They serve as probes of abundance gradients and chemical enrichment history of the ISM.

scholarly journals Kinematics and dynamics of galactic Planetary Nebulae

1997 ◽  
Vol 180 ◽  
pp. 407-407
Author(s):  
S. Durand
Keyword(s):  
Emission Line ◽  
Milky Way ◽  
Large Range ◽  
Planetary Nebulae ◽  
The Other ◽  
Initial Mass ◽  
Kinematics And Dynamics ◽  
Astrophysical Interest ◽  
Bright Emission ◽  
Bright Emission Line

Planetary Nebulae (PNe) are transient objects of considerable astrophysical interest: there are thought to descend from low and intermediate initial mass stars and therefore cover a large range of ages. On the other hand there are easily identified thanks to their bright emission-line spectra. In view of this it is perhaps surprising that little use has been made of PNe for kinematical studies of the Milky Way.

scholarly journals Planetary Nebulae and the Chemical Evolution of Galaxies

1983 ◽  
Vol 103 ◽  
pp. 463-472 ◽  
Author(s):  
Alfonso Serrano
Keyword(s):  
Star Formation ◽  
Chemical Evolution ◽  
Planetary Nebulae ◽  
Low Mass Stars ◽  
Chemical Enrichment ◽  
The Past ◽  
The Galaxy ◽  
History Of ◽  
Low Mass

Tinsley (1978) has done an excellent review that illustrates the methods and concepts that can be developed to assess the effects of planetary nebulae (PN) on the long-term history of the galaxy. Tinsley concluded that research in PN could put constraints on the past rate of star formation and provide information on chemical enrichment by low mass stars.

scholarly journals The star formation history of galaxies in 3D: CALIFA perspective

2014 ◽  
Vol 10 (S309) ◽  
pp. 99-104
Author(s):  
R. M. González Delgado ◽  
R. Cid Fernandes ◽  
R. García-Benito ◽  
E. Pérez ◽  
A. L. de Amorim ◽  
...  
Keyword(s):  
Star Formation ◽  
Surface Density ◽  
Spectral Synthesis ◽  
Stellar Mass ◽  
Star Formation History ◽  
Chemical Enrichment ◽  
Radial Profiles ◽  
Formation History ◽  
The Galaxy ◽  
History Of

AbstractWe resolve spatially the star formation history of 300 nearby galaxies from the CALIFA integral field survey to investigate: a) the radial structure and gradients of the present stellar populations properties as a function of the Hubble type; and b) the role that plays the galaxy stellar mass and stellar mass surface density in governing the star formation history and metallicity enrichment of spheroids and the disks of galaxies. We apply the fossil record method based on spectral synthesis techniques to recover spatially and temporally resolved maps of stellar population properties of spheroids and spirals with galaxy mass from 109 to 7×1011 M⊙. The individual radial profiles of the stellar mass surface density (μ⋆), stellar extinction (AV), luminosity weighted ages (〈logage〉L), and mass weighted metallicity (〈log Z/Z⊙〉M) are stacked in seven bins of galaxy morphology (E, S0, Sa, Sb, Sbc, Sc and Sd). All these properties show negative gradients as a sight of the inside-out growth of massive galaxies. However, the gradients depend on the Hubble type in different ways. For the same galaxy mass, E and S0 galaxies show the largest inner gradients in μ⋆; and Andromeda-like galaxies (Sb with log M⋆ (M⊙) ∼ 11) show the largest inner age and metallicity gradients. In average, spiral galaxies have a stellar metallicity gradient ∼ −0.1 dex per half-light radius, in agreement with the value estimated for the ionized gas oxygen abundance gradient by CALIFA. A global (M⋆-driven) and local (μ⋆-driven) stellar metallicity relation are derived. We find that in disks, the stellar mass surface density regulates the stellar metallicity; in spheroids, the galaxy stellar mass dominates the physics of star formation and chemical enrichment.

scholarly journals Extragalactic planetary nebulae: Tracers of the chemical evolution of nearby galaxies

2011 ◽  
Vol 7 (S283) ◽  
pp. 251-258 ◽  
Author(s):  
Laura Magrini ◽  
Letizia Stanghellini ◽  
Denise R. Gonçalves
Keyword(s):  
Chemical Evolution ◽  
Stellar Evolution ◽  
Planetary Nebulae ◽  
Spectroscopic Studies ◽  
Disk Galaxies ◽  
Chemical Enrichment ◽  
History Of ◽  
External Galaxies ◽  
Low Metallicity ◽  
Nearby Galaxies

AbstractThe study of the chemical composition of Planetary Nebulae in external galaxies is of paramount importance for the fields of stellar evolution and chemical enrichment history of galaxies. In recent years a number of spectroscopic studies with 6-8m-class telescopes have been devoted to this subject improving our knowledge of, among other, the time-evolution of the radial metallicity gradient in disk galaxies, the chemical evolution of dwarf galaxies, and stellar evolution at low metallicity.

scholarly journals Historical overview of planetary nebulae research

2011 ◽  
Vol 7 (S283) ◽  
pp. 1-8
Author(s):  
Sun Kwok
Keyword(s):  
Planetary Nebulae ◽  
Central Star ◽  
Asymptotic Giant Branch ◽  
Evolutionary Status ◽  
Complex Molecules ◽  
Chemical Enrichment ◽  
Star Studies ◽  
The Galaxy ◽  
Underlying Causes

AbstractPlanetary nebulae (PNs) were first discovered over 200 years ago and our understanding of these objects has undergone significant evolution over the years. Developments in astronomical optical spectroscopy and atomic physics have shown that PNe are gaseous objects photoionized by UV radiation from a hot central star. Studies of the kinematics of the nebulae coupled with progress in theories of stellar evolution have led to the identification that PNe are evolved stars and progenitors of white dwarfs. Development of infrared and millimeter-wave technology in the 1970s made us realize that there is significant amount of neutral matter (molecules and dust) in PNe. The link of PNe to the stellar winds from their progenitor asymptotic giant branch (AGB) stars and subsequent dynamical interactions are now believed to be the underlying causes of the morphological structures of PNe. The role of PNe as prolific molecular factories producing complex molecules and organic solids has significant implications on the chemical enrichment of the Galaxy.In this paper, we discuss the misconceptions and errors that we have encountered in our journey of understanding the nature of PN. The various detours and dead ends that had happened during our quest to pin down the evolutionary status and causes of nebulae ejection will be discussed. As there are still many unsolved problems in PN research, these lessons of history have much to offer for future progress in this field.

scholarly journals Mentari: A pipeline to model the galaxy SED using semi analytic models

2019 ◽  
Vol 15 (S341) ◽  
pp. 119-123
Author(s):  
Dian Triani ◽  
Darren Croton ◽  
Manodeep Sinha
Keyword(s):  
Star Formation ◽  
Galaxy Evolution ◽  
Spectral Energy Distribution ◽  
Cosmic Time ◽  
Spectral Energy ◽  
Chemical Enrichment ◽  
The Galaxy ◽  
History Of ◽  
Gas Accretion ◽  
Analytic Models

AbstractWe build a theoretical picture of how the light from galaxies evolves across cosmic time. In particular, we predict the evolution of the galaxy spectral energy distribution (SED) by carefully integrating the star formation and metal enrichment histories of semi-analytic model (SAM) galaxies and combining these with stellar population synthesis models which we call mentari. Our SAM combines prescriptions to model the interplay between gas accretion, star formation, feedback process, and chemical enrichment in galaxy evolution. From this, the SED of any simulated galaxy at any point in its history can be constructed and compared with telescope data to reverse engineer the various physical processes that may have led to a particular set of observations. The synthetic SEDs of millions of simulated galaxies from mentari can cover wavelengths from the far UV to infrared, and thus can tell a near complete story of the history of galaxy evolution.

scholarly journals The population of planetary nebulae near the Galactic Centre: chemical abundances

2016 ◽  
Vol 12 (S323) ◽  
pp. 339-340
Author(s):  
M. Mollá ◽  
O. Cavichia ◽  
R. D. D. Costa ◽  
W. J. Maciel
Keyword(s):  
Luminosity Function ◽  
Planetary Nebulae ◽  
Galactic Centre ◽  
Physical Parameters ◽  
Chemical Compositions ◽  
Galactic Bulge ◽  
Chemical Abundances ◽  
Chemical Enrichment ◽  
History Of ◽  
Low Dispersion

AbstractIn this work, we report physical parameters and abundances derived for a sample of 15 high extinction planetary nebulae located in the inner 2° of the Galactic bulge, based on low dispersion spectroscopy secured at the SOAR telescope using the Goodman spectrograph. The new data allow us to extend our database including older, weaker objects that are at the faint end of the planetary nebulae luminosity function. The data provide chemical compositions for PNe located in this region of the bulge to explore the chemical enrichment history of the central region of the Galactic bulge. The results show that the abundances of our sample are skewed to higher metallicities than previous data in the outer regions of the bulge. This can indicate a faster chemical enrichment taking place at the Galactic centre.

scholarly journals SUPPRESSION OF FIBER MODAL NOISE INDUCED RADIAL VELOCITY ERRORS FOR BRIGHT EMISSION-LINE CALIBRATION SOURCES

2014 ◽  
Vol 786 (1) ◽  
pp. 18 ◽  
Author(s):  
Suvrath Mahadevan ◽  
Samuel Halverson ◽  
Lawrence Ramsey ◽  
Nick Venditti
Keyword(s):  
Radial Velocity ◽  
Emission Line ◽  
Modal Noise ◽  
Bright Emission ◽  
Bright Emission Line

scholarly journals Abundances in Local Group Planetary Nebulae

1995 ◽  
Vol 10 ◽  
pp. 480-482
Author(s):  
James B. Kaler
Keyword(s):  
Local Group ◽  
Initial Conditions ◽  
Planetary Nebulae ◽  
Magellanic Clouds ◽  
Chemical Compositions ◽  
Core Mass ◽  
Know How ◽  
Chemical Enrichment ◽  
Clear Link ◽  
The Galaxy

We are able to measure the chemical compositions of hundreds of planetary nebulae in our own Galaxy and in the Magellanic Clouds. Why, therefore, do we need to expend the effort to observe much more difficult targets in other Local Group galaxies? A severe lack of distances does not allow us to place Galactic planetary nuclei on the log L-log T plane with any degree of accuracy, so we cannot properly examine composition differences relative to core mass and state of evolution. We can perform such tasks for Magellanic Cloud objects, but do not know how the Clouds’ low-metallicities affect the results, and thus do not know how this sample of planetaries relates to the nebulae in our own system. We know, for example, that in the Clouds, nitrogen enrichment begins above a core mass of about 0.68 M⊙ (Kaler and Jacoby 1990), but other than a clear link between core mass and chemical enrichment in the Galaxy, do not know at what point it becomes important. To study such relationships, we therefore have to go to other galaxies with a variety of initial conditions for which distances are secure, namely those of the Local Group.

scholarly journals Orientation of galactic bulge planetary nebulae toward the Galactic center

2014 ◽  
Vol 10 (S312) ◽  
pp. 128-130
Author(s):  
Ashkbiz Danehkar ◽  
Quentin A. Parker
Keyword(s):  
Emission Line ◽  
Galactic Center ◽  
Planetary Nebulae ◽  
Wide Field ◽  
Spatially Resolved ◽  
Integral Field Spectroscopy ◽  
Field Spectroscopy ◽  
National University ◽  
Hα Emission ◽  
Integral Field

AbstractWe have used the Wide Field Spectrograph on the Australian National University 2.3-m telescope to perform the integral field spectroscopy for a sample of the Galactic planetary nebulae. The spatially resolved velocity distributions of the Hα emission line were used to determine the kinematic features and nebular orientations. Our findings show that some bulge planetary nebulae toward the Galactic center have a particular orientation.

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