scholarly journals Planetary nebulae in the Magellanic Clouds and Local Group galaxies

2011 ◽  
Vol 7 (S283) ◽  
pp. 227-234
Author(s):  
Warren A. Reid
Keyword(s):  
Milky Way ◽  
Local Group ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Magellanic Clouds ◽  
The Past ◽  
Spatially Resolved ◽  
Multi Wavelength ◽  
Large Telescopes ◽  
Central Stars

AbstractThe Magellanic Clouds are close enough to the Milky Way to provide an excellent environment in which to study extragalactic PNe. Most of these PNe are bright enough to be spectroscopically observed and spatially resolved. With the latest high resolution detectors on today's large telescopes it is even possible to directly observe a large number of central stars. Magellanic Cloud (MC) PNe provide several astrophysical benefits including low overall extinction and a good sample size covering a large range of dynamic evolutionary timescales while the known distances provide a direct estimation of luminosity and physical dimensions. Multi-wavelength surveys are revealing intriguing differences between MC and Galactic PNe.Over the past 5 years there has been a substantial increase in the number of PNe discovered in the Large Magellanic Cloud (LMC) in particular. Deep surveys have allowed the faint end of the luminosity function to be investigated, finally providing a strong clue to its overall shape. In so doing, the surveys are approaching completeness, estimated at ~80% in the LMC (~120 deg2) and ~65% in the Small Magellanic Cloud (SMC) (~20 deg2).The number of galaxies comprising the Local Group (LG) and its outskirts has been growing steadily over the past 5 years and now numbers 48. Most of the 7 newly discovered galaxies are dwarf spheroidal (dSph) in structure and range from 7.6 to 755 kpc from the Milky Way. Nonetheless, there are no published searches for PNe in any of these galaxies to date. Apart from the LMC and Milky Way, the number of PN discoveries has been very modest and only one additional LG galaxy has been surveyed for PNe over the past 5 years. This paper provides the number of Local Group PNe currently known and estimates each galaxy's total PN population.

scholarly journals Search for binary central stars of the Magellanic Clouds PNe

2016 ◽  
Vol 12 (S323) ◽  
pp. 384-385
Author(s):  
Marcin Gładkowski ◽  
Marcin Hajduk ◽  
Igor Soszyński
Keyword(s):  
Milky Way ◽  
Central Star ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Magellanic Clouds ◽  
Small Magellanic Cloud ◽  
Photometric Analysis ◽  
Gravitational Experiment ◽  
The Galaxy ◽  
Central Stars

AbstractThe Optical Gravitational Experiment (OGLE) was effectively used in discovering binary central stars of planetary nebulae (CSPNe). About 50 binary CSPNe have been hitherto identified in the Galaxy, almost half of them were detected in the OGLE database. We used the OGLE data to search for binary CSPNe in the Magellanic Clouds. We also searched for PNe mimics and removed them from the PNe sample. Here, we present results of the photometric analysis for Small Magellanic Cloud (SMC) and our progress on search of binary central stars in the Large Magellanic Cloud (LMC). So far, we have discovered one binary central star of the PN beyond the Milky Way, which is located in the Small Magellanic Cloud.

Novae in the Magellanic Clouds

1979 ◽  
Vol 46 ◽  
pp. 96-101
Author(s):  
J.A. Graham
Keyword(s):  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Magellanic Clouds ◽  
University Of Michigan ◽  
The Past ◽  
Spectroscopic Information ◽  
Objective Prism ◽  
The University ◽  
Small Cloud ◽  
Low Dispersion

During the past several years, a systematic search for novae in the Magellanic Clouds has been carried out at Cerro Tololo Inter-American Observatory. The Curtis Schmidt telescope, on loan to CTIO from the University of Michigan is used to obtain plates every two weeks during the observing season. An objective prism is used on the telescope. This provides additional low-dispersion spectroscopic information when a nova is discovered. The plates cover an area of 5°x5°. One plate is sufficient to cover the Small Magellanic Cloud and four are taken of the Large Magellanic Cloud with an overlap so that the central bar is included on each plate. The methods used in the search have been described by Graham and Araya (1971). In the CTIO survey, 8 novae have been discovered in the Large Cloud but none in the Small Cloud. The survey was not carried out in 1974 or 1976. During 1974, one nova was discovered in the Small Cloud by MacConnell and Sanduleak (1974).

scholarly journals An overview of the structure and kinematics of the Magellanic Clouds

1991 ◽  
Vol 148 ◽  
pp. 15-23 ◽  
Author(s):  
B. E. Westerlund
Keyword(s):  
Star Formation ◽  
Observational Data ◽  
Spiral Structure ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Magellanic Clouds ◽  
Line Of Sight ◽  
Small Magellanic Cloud ◽  
Complex Velocity ◽  
The Past

A vast amount of observational data concerning the structure and kinematics of the Magellanic Clouds is now available. Many basic quantities (e.g. distances and geometry) are, however, not yet sufficiently well determined. Interactions between the Small Magellanic Cloud (SMC), the Large Magellanic Cloud (LMC) and our Galaxy have dominated the evolution of the Clouds, causing bursts of star formation which, together with stochastic self-propagating star formation, produced the observed structures. In the youngest generation in the LMC it is seen as an intricate pattern imitating a fragmented spiral structure. In the SMC much of the fragmentation is along the line of sight complicating the reconstruction of its history. The violent events in the past are also recognizable in complex velocity patterns which make the analysis of the kinematics of the Clouds difficult.

scholarly journals The interstellar medium of the Magellanic Clouds from absorption lines

1991 ◽  
Vol 148 ◽  
pp. 401-406 ◽  
Author(s):  
Klaas S. De Boer
Keyword(s):  
Interstellar Medium ◽  
Absorption Line ◽  
Milky Way ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Magellanic Clouds ◽  
Absorption Lines ◽  
Small Magellanic Cloud ◽  
General Aspects

General aspects of ISM studies using absorption line studies are given and available data are reviewed. Topics are: galactic foreground gas, individual fields in the Magellanic Clouds (MCs) and MC coronae. Overall investigations are discussed. It is demonstrated that the metals in the gas of the Large Magellanic Cloud (LMC) and Small Magellanic Cloud (SMC) are a factor of 3 and 10, respectively, in abundance below solar levels. The depletion pattern in the LMC is similar to that of the Milky Way.

scholarly journals The Large Magellanic Cloud PN population

2015 ◽  
Vol 11 (A29B) ◽  
Author(s):  
Warren A. Reid
Keyword(s):  
Milky Way ◽  
Central Star ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Parent Population ◽  
The Past ◽  
Standard Candle ◽  
Evolutionary Paths ◽  
Stellar Density

AbstractThe Large Magellanic Cloud (LMC) and Small Magellanic Cloud (SMC) allow us to study late stellar evolution in environments that are respectively about a half and a quarter the metallicity of the Milky Way. With a known distance and low reddening, the LMC is an excellent environment to study PNe and conduct multiple studies. Over the past twelve months we have used the UKST Hα survey to complete our search for faint PNe in the outer most LMC beyond the 64 deg2area previously covered. Follow-up spectroscopy using AAOmega on the AAT and the 2.3-m telescope at Siding Spring Observatory have yielded a further 22 new LMC PNe while confirming the 8 previously known in the outer LMC. Medium- and high-resolution spectra have been used to measure fluxes and derive densities, mass and central star temperatures. A strong correlation is found between PNe and stellar density. This is visually displayed and given an empirical value of α = 1 PN / 2.5 × 106L⊙. The current [Oiii]-based PNLF, apart from providing an excellent standard candle, contains information about the parent population. The new PNLF, which extends down nine magnitudes, permits investigation of the faint end, the overall effects of internal extinction and provides clues to explain the insensitivity of the PNLF cutoff. When compared to the ionised density and mass of LMC PNe, the PNLF reveals it’s bimodal characteristics. Two separate evolutionary paths are evident for young, evolving PNe.

scholarly journals Planetary nebulae in the VISTA Magellanic Cloud (VMC) Survey

2011 ◽  
Vol 7 (S283) ◽  
pp. 444-445
Author(s):  
Brent Miszalski ◽  
Ralph Napiwotzki ◽  
Maria-Rosa L. Cioni ◽  
Martin A. T. Groenewegen ◽  
Jose M. Oliveira ◽  
...  
Keyword(s):  
Luminosity Function ◽  
Near Infrared ◽  
Planetary Nebulae ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Magellanic Clouds ◽  
First Year ◽  
Complementary Role ◽  
Initial Results ◽  
Central Stars

AbstractThe multi-epoch YJKs sub-arcsecond photometry of the VMC survey provides a long anticipated deep near-infrared (NIR) window into further understanding the stellar populations of the Magellanic Clouds. The first year of observations consisted of six tiles covering ~9% of the Large Magellanic Cloud (LMC) survey region and contains 102 objects previously classified as planetary nebulae (PNe). A large proportion of the sample were found to be contaminated by non-PNe. These initial results underline the importance of establishing a clean catalogue of LMC PNe before they are applied in areas such as the planetary nebula luminosity function (PNLF) and searches for binary central stars. As the VMC survey progresses it will play a fundamental role in cleaning extant PN catalogues and a complementary role in the discovery of new PNe.

scholarly journals The VMC survey

2020 ◽  
Vol 641 ◽  
pp. A134
Author(s):  
Thomas Schmidt ◽  
Maria-Rosa L. Cioni ◽  
Florian Niederhofer ◽  
Kenji Bekki ◽  
Cameron P. M. Bell ◽  
...  
Keyword(s):  
Proper Motion ◽  
Milky Way ◽  
Dwarf Galaxies ◽  
Dynamical Evolution ◽  
Large Magellanic Cloud ◽  
Small Population ◽  
Magellanic Cloud ◽  
Magellanic Clouds ◽  
Proper Motions ◽  
Flow Motion

Context. The Magellanic Clouds are a nearby pair of interacting dwarf galaxies and satellites of the Milky Way. Studying their kinematic properties is essential to understanding their origin and dynamical evolution. They have prominent tidal features and the kinematics of these features can give hints about the formation of tidal dwarfs, galaxy merging and the stripping of gas. In addition they are an example of dwarf galaxies that are in the process of merging with a massive galaxy. Aims. The goal of this study is to investigate the kinematics of the Magellanic Bridge, a tidal feature connecting the Magellanic Clouds, using stellar proper motions to understand their most recent interaction. Methods. We calculated proper motions based on multi-epoch Ks-band aperture photometry, which were obtained with the Visible and Infrared Survey Telescope for Astronomy (VISTA), spanning a time of 1−3 yr, and we compared them with Gaia Data Release 2 (DR2) proper motions. We tested two methods for removing Milky Way foreground stars using Gaia DR2 parallaxes in combination with VISTA photometry or using distances based on Bayesian inference. Results. We obtained proper motions for a total of 576 411 unique sources over an area of 23 deg2 covering the Magellanic Bridge including mainly Milky Way foreground stars, background galaxies, and a small population of possible Magellanic Bridge stars (< 15 000), which mostly consist of giant stars with 11.0 <  Ks <  19.5 mag. The first proper motion measurement of the Magellanic Bridge centre is 1.80 ± 0.25 mas yr−1 in right ascension and −0.72 ± 0.13 mas yr−1 in declination. The proper motion measurements of stars along the Magellanic Bridge from the VISTA survey of the Magellanic Cloud system (VMC) and Gaia DR2 data confirm a flow motion from the Small to the Large Magellanic Cloud. This flow can now be measured all across the entire length of the Magellanic Bridge. Conclusions. Our measurements indicate that the Magellanic Bridge is stretching. By converting the proper motions to tangential velocities, we obtain ∼110 km s−1 in the plane of the sky. Therefore it would take a star roughly 177 Myr to cross the Magellanic Bridge.

COMPARISON OF GENERAL RELATIVISTIC AND PSEUDO-NEWTONIAN DESCRIPTION OF MAGELLANIC-CLOUDS MOTION IN THE FIELD OF MILKY WAY

2012 ◽  
Vol 21 (04) ◽  
pp. 1250031 ◽  
Author(s):  
ZDENĚK STUCHLÍK ◽  
JAN SCHEE
Keyword(s):  
Cosmological Constant ◽  
Time Evolution ◽  
Milky Way ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Magellanic Clouds ◽  
De Sitter ◽  
Local Scaling ◽  
Relative Contribution ◽  
General Relativistic

We test precision of the Cosmological Paczynski–Wiita (CPW) potential reflecting properties of the Schwarzschild–de Sitter (SdS) spacetimes in modeling dynamical phenomena related to galaxy motion. We consider a simplified model of Magellanic Clouds moving in the field of Milky Way as test particles. Time evolution of their position along trajectories obtained in the CPW framework using the notion of Newtonian time is compared to the one obtained in the fully general relativistic (GR) approach when the time evolution is expressed in terms of time related to the location of Earth in the Galaxy field. The differences in the position-evolution of the Magellanic Clouds obtained in the CPW and GR approaches are given for appropriately chosen values of the Milky Way mass. It is shown that the integrated relativistic corrections represent ~10-5 part of the Newtonian CPW predictions for the orbital characteristics of the motion and slightly grow with Galaxy mass growing, being at least by one order higher than the local scaling GR corrections. The integrated orbital GR corrections thus could be important only in very precise modeling of the motion of Magellanic Clouds. The CPW framework is used to show that, quite surprisingly, the influence of the cosmological constant on the Magellanic Clouds motion can be strong and significantly alters the trajectories of Magellanic Clouds and time evolution along them. The relative contribution of the cosmological constant is ~10-1 or higher. It is most profoundly demonstrated by the increase of the binding mass that represents 22% for Small Magellanic Cloud and even 47% for Large Magellanic Cloud, putting serious doubts on gravitational binding to the Milky Way in the later case.

scholarly journals Characterising the Protostellar Population of the Magellanic Clouds with VLT/SINFONI

2015 ◽  
Vol 11 (S315) ◽  
Author(s):  
Jacob Ward ◽  
Joana Oliveira ◽  
Jacco van Loon ◽  
Marta Sewilo
Keyword(s):  
Star Formation ◽  
Milky Way ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Magellanic Clouds ◽  
Emission Lines ◽  
Young Stellar Objects ◽  
Small Magellanic Cloud ◽  
Stellar Objects ◽  
Accretion Rates

AbstractAt distances of ~50 kpc and ~60 kpc for the Large Magellanic Cloud (LMC) and Small Magellanic Cloud (SMC) respectively the Magellanic Clouds present us with a unique opportunity to study star formation in environments outside our own galaxy. Through Spitzer and Herschel photometry and spectroscopy, samples of Young Stellar Objects (YSOs) have been selected and spectroscpically confirmed in the Magellanic Clouds. Here we present some of the key results of our SINFONI K-band observations towards massive YSOs in the Magellanic Clouds. We resolve a number of Spitzer sources into multiple, previously unresolved, components and our analysis of emission lines suggest higher accretion rates and different disc properties compared with massive YSOs in the Milky Way.

scholarly journals Reconstructing the Star Formation History of the Magellanic Clouds

1999 ◽  
Vol 192 ◽  
pp. 72-78
Author(s):  
Jason Harris ◽  
Dennis Zaritsky ◽  
Eva K. Grebel ◽  
Ian Thompson
Keyword(s):  
Star Formation ◽  
Stellar Population ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Magellanic Clouds ◽  
Photometric Data ◽  
Star Formation History ◽  
Spatially Resolved ◽  
Formation History ◽  
History Of

We are developing an algorithm to determine the star formation history (SFH) of a mixed stellar population. We will apply the algorithm to hundreds of regions in our Magellanic Clouds Photometric Survey data and reconstruct the spatially resolved star formation history of the Large Magellanic Cloud (LMC) and the Small Magellanic Cloud (SMC). In this paper, we demonstrate the algorithm on a typical region in the LMC, focussing on the obstacles and challenges facing us in attempting to reliably extract the SFH from photometric data.

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