scholarly journals Structure of the Milky Way and the distribution of young stellar clusters

2006 ◽  
Vol 2 (S241) ◽  
Author(s):  
Maria Messineo ◽  
Karl M. Menten ◽  
Harm J. Habing ◽  
Monika Petr-Gotzens ◽  
Frédéric Schuller
Keyword(s):  
Milky Way ◽  
Stellar Clusters

scholarly journals The implications of clustered star formation for (proto)planetary systems and habitability

2018 ◽  
Vol 14 (S345) ◽  
pp. 61-65
Author(s):  
J. M. Diederik Kruijssen ◽  
Steven N. Longmore
Keyword(s):  
Star Formation ◽  
Large Scale ◽  
Milky Way ◽  
Planetary Systems ◽  
Habitable Zone ◽  
Stellar Clusters ◽  
Galaxy Mergers ◽  
Multi Scale ◽  
The Past ◽  
Scale Properties

AbstractStar formation is spatially clustered across a range of environments, from dense stellar clusters to unbound associations. As a result, radiative or dynamical interactions with neighbouring stars disrupt (proto)planetary systems and limit their radii, leaving a lasting impact on their potential habitability. In the solar neighbourhood, we find that the vast majority of stars form in unbound associations, such that the interaction of (proto)planetary systems with neighbouring stars is limited to the densest sub-regions. However, the fraction of star formation occurring in compact clusters was considerably higher in the past, peaking at ∼50% in the young Milky Way at redshift z ∼ 2. These results demonstrate that the large-scale star formation environment affects the demographics of planetary systems and the occupation of the habitable zone. We show that planet formation is governed by multi-scale physics, in which Mpc-scale events such as galaxy mergers affect the AU-scale properties of (proto)planetary systems.

scholarly journals Towards a multi-scale understanding of the gas-star formation cycle in the Central Molecular Zone

2016 ◽  
Vol 11 (S322) ◽  
pp. 64-74
Author(s):  
J. M. Diederik Kruijssen
Keyword(s):  
Star Formation ◽  
Milky Way ◽  
High Redshift ◽  
Three Dimensional ◽  
Orbital Dynamics ◽  
Molecular Gas ◽  
Stellar Clusters ◽  
High Redshift Galaxies ◽  
Multi Scale ◽  
The Galaxy

AbstractThe Central Molecular Zone (CMZ, the central 500 pc of the Milky Way) contains the largest reservoir of high-density molecular gas in the Galaxy, but forms stars at a rate 10–100 times below commonly-used star formation relations. We discuss recent efforts in understanding how the nearest galactic nucleus forms its stars. The latest models of the gas inflow, star formation, and feedback duty cycle reproduce the main observable features of the CMZ, showing that star formation is episodic and that the CMZ currently resides at a star formation minimum. Using orbital modelling, we derive the three-dimensional geometry of the CMZ and show how the orbital dynamics and the star formation potential of the gas are closely coupled. We discuss how this coupling reveals the physics of star formation and feedback under the conditions seen in high-redshift galaxies, and promotes the formation of the densest stellar clusters in the Galaxy.

Young Massive Stellar Clusters in the Milky Way: the Cl1813-178 and GLIMPSE 9 Clusters

2011 ◽  
pp. 185-190
Author(s):  
Maria Messineo ◽  
Ben Davies ◽  
Donald F. Figer ◽  
Christine Trombley ◽  
Elena Valenti ◽  
...  
Keyword(s):  
Milky Way ◽  
Stellar Clusters

scholarly journals Stellar Clusters in the Outermost Milky Way Galaxy

1999 ◽  
Vol 192 ◽  
pp. 85-88
Author(s):  
J. E. Hesser ◽  
P. B. Stetson ◽  
S. van den Bergh ◽  
M. Bolte ◽  
J. A. Johnson ◽  
...  
Keyword(s):  
Milky Way ◽  
Star Clusters ◽  
Stellar Clusters ◽  
Milky Way Galaxy ◽  
Insight Into

HST V, I color-magnitude diagrams (CMDs) of four outer-halo clusters, NGC 2419, Pa13, Pal4 and Eridanus, provide insight into the relative ages of old star clusters throughout the 200 kpc diameter volume sampled, and thus into the formation epoch of the Milky Way galaxy.

scholarly journals Painting a portrait of the Galactic disc with its stellar clusters

2020 ◽  
Vol 640 ◽  
pp. A1 ◽  
Author(s):  
T. Cantat-Gaudin ◽  
F. Anders ◽  
A. Castro-Ginard ◽  
C. Jordi ◽  
M. Romero-Gómez ◽  
...  
Keyword(s):  
Milky Way ◽  
Scale Height ◽  
Stellar Clusters ◽  
Galactic Disc ◽  
Present Sample ◽  
Stellar Cluster ◽  
Homogeneous Cluster ◽  
Cluster Age ◽  
Galactic Warp ◽  
Spiral Arm

Context. The large astrometric and photometric survey performed by the Gaia mission allows for a panoptic view of the Galactic disc and its stellar cluster population. Hundreds of stellar clusters were only discovered after the latest Gaia data release (DR2) and have yet to be characterised. Aims. Here we make use of the deep and homogeneous Gaia photometry down to G = 18 to estimate the distance, age, and interstellar reddening for about 2000 stellar clusters identified with Gaia DR2 astrometry. We use these objects to study the structure and evolution of the Galactic disc. Methods. We relied on a set of objects with well-determined parameters in the literature to train an artificial neural network to estimate parameters from the Gaia photometry of cluster members and their mean parallax. Results. We obtain reliable parameters for 1867 clusters. Our catalogue confirms the relative lack of old stellar clusters in the inner disc (with a few notable exceptions). We also quantify and discuss the variation of scale height with cluster age, and we detect the Galactic warp in the distribution of old clusters. Conclusions. This work results in a large and homogeneous cluster catalogue, allowing one to trace the structure of the disc out to distances of ∼4 kpc. However, the present sample is still unable to trace the outer spiral arm of the Milky Way, which indicates that the outer disc cluster census might still be incomplete.

scholarly journals Isochrone fitting of ACS survey globular clusters using the PAdova and TRieste Stellar Evolution Code (PARSEC)

2021 ◽  
Vol 2145 (1) ◽  
pp. 012004
Author(s):  
N Chehlaeh
Keyword(s):  
Stellar Evolution ◽  
Globular Clusters ◽  
Milky Way ◽  
Hubble Space Telescope ◽  
Distance Estimation ◽  
Physical Parameters ◽  
Distance Modulus ◽  
Stellar Clusters ◽  
Formation And Evolution ◽  
Fundamental Physical

Abstract We present new isochrone fits to color magnitude diagrams (CMDs) of five globular clusters (GCs) including NGC 1261, NGC 1851, NGC 2298, NGC 3201, and NGC 4590. We used archival data obtained from the Advanced Camera for Survey (ACS) on board the Hubble Space Telescope (HST). The data of these five GCs were collected in F606W (V) and F814W (I) filters. In this study, the isochrone fitting to GC CMDs was analyzed using the PAdova and TRieste Stellar Evolution Code (PARSEC), which is the fundamental tool for age and distance estimation and modelling the evolution of stellar clusters and other galaxies. The main purpose is to estimate the fundamental physical properties of the GC samples using the PARSEC code and compare with results from published articles. The fundamental physical parameters determined in the study are age, metallicity, reddening, and distance modulus. The theoretical isochrone fits properly with the shape of CMD at the turn-off point that can be used to estimate the age and metallicity of clusters. We found that the age of these five GCs; NGC 1261, NGC 1851, NGC 2298, NGC 3201, and NGC 4590 are 12.6±1.0 Gyr, 12.0±1.0 Gyr, 12.7±1.0 Gyr, 12.0±1.0 Gyr, and 13.0±1.0 Gyr, respectively. Among the analyzed clusters, the results show that NGC 4590 is the oldest GC and has lowest metallicity value compare with other cluster samples. Studies of the properties and distribution of GCs play an important role to understand formation and evolution of the Milky Way.

scholarly journals The future of IMF studies with the ELT and MICADO

2020 ◽  
Vol 639 ◽  
pp. A120
Author(s):  
K. Leschinski ◽  
J. Alves
Keyword(s):  
Adaptive Optics ◽  
Milky Way ◽  
Magellanic Clouds ◽  
Initial Mass Function ◽  
High Mass ◽  
Stellar Clusters ◽  
Local Universe ◽  
Space Telescope ◽  
Young Clusters ◽  
The Imf

Context. Young stellar cluster cores in the local Universe provide the most pristine information available on the stellar initial mass function (IMF), but their stellar densities are too high to be resolved by present-day instrumentation. With a resolving power 100 times better than the Hubble Space Telescope, the Multi-Adaptive Optics Imaging CameraA for Deep Observations (MICADO), which is the near-infrared camera on the Extremely Large Telescope (ELT), will for the first time provide access to a significant number of dense young stellar clusters that are critical for direct studies on the universality and shape of the IMF. Aims. In this work we aim to estimate the lowest stellar mass that MICADO will be able to reliably detect given a stellar density and distance. We also show that instrumental effects that will play a critical role, and report the number of young clusters that will be accessible for IMF studies in the local Universe with the ELT. Methods. We used SimCADO*, the instrument simulator package for the MICADO camera, to generate observations of 56 dense stellar regions with densities similar to the cores of young stellar clusters. We placed the cluster fields at distances between 8 kpc and 5 Mpc from the Earth, implying core densities from 102 to 105 stars arcsec−2, and determined the lowest reliably observable mass for each stellar field through point-spread function fitting photometry. Results. Our results show that stellar densities of <103 stars arcsec−2 will be easily resolvable by MICADO. The lowest reliably observable mass in the Large Magellanic Cloud will be around 0.1 M⊙ for clusters with densities <103 stars arcsec−2. MICADO will be able to access the stellar content of the cores of all dense young stellar clusters in the Magellanic Clouds, allowing the peak and shape of the IMF to be studied in great detail outside the Milky Way. At a distance of 2 Mpc, all stars with M > 2 M⊙ will be resolved in fields of <104 stars arcsec−2, allowing the high-mass end of the IMF to be studied in all galaxies out to and including NGC 300. Conclusions. We show that MICADO on the ELT will be able to probe the IMF of star clusters that are ten times denser than what the James Webb Space Telescope will be able to access, and over one hundred times denser than the clusters that the Hubble Space Telescope can successfully resolve. While the sensitivity of MICADO will not allow us to study the brown dwarf regime outside the Milky Way, it will enable access to all stellar members of over 1000 young clusters in the Milky Way and the Magellanic Clouds. Furthermore, direct measurements of the Salpeter slope of the IMF will be possible in over 1500 young clusters out to a distance of 5 Mpc. MICADO on the ELT will be able to measure resolved IMFs for a large ensemble of young clusters under starkly different environments and test the universality of the IMF in the local Universe.

scholarly journals HCN Hyperfine Ratio Analysis of Massive Molecular Clumps

2015 ◽  
Vol 12 (S316) ◽  
pp. 131-132
Author(s):  
William Schap ◽  
Peter Barnes ◽  
Adam Ginsburg ◽  
Antonio Ordonez
Keyword(s):  
Column Density ◽  
Milky Way ◽  
Cluster Formation ◽  
Ratio Analysis ◽  
Stellar Clusters ◽  
Molecular Line ◽  
Physical Conditions ◽  
Uniform Sample ◽  
Large Sector ◽  
Massive Cluster

AbstractThe CHaMP project has identified a uniform sample of 303 massive (20–8000 M⊙), dense (200–30,000 cm−3) molecular clumps in a large sector of the southern Milky Way that includes much of the Carina Arm. These are the kinds of clumps that are likely to be the precursors to IRDCs, large stellar clusters, and massive stars. We report new results of the physical conditions in these clouds based on the J=1 → 0 emission at 3mm from the HCN molecule. Analysis of the HCN emission from these clumps reveals that the physical conditions in the gas (i.e., the excitation temperature, optical depth, and column density) do not follow the molecular line emissivity in a straightforward way. This means that large fractions of the molecular material involved in massive cluster formation, while not completely“dark”, are under-luminous and easily missed in certain studies.

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