STAR FORMATION HISTORY OF A YOUNG SUPER-STAR CLUSTER IN NGC 4038/39: DIRECT DETECTION OF LOW-MASS PRE-MAIN SEQUENCE STARS

We report a new star formation history for the Tucana dwarf spheroidal galaxy, obtained from a new look at a deep HST/ACS colour-magnitude diagram. We combined information from the main sequence turn-off and the horizontal branch to resolve the ancient star formation rates on a finer temporal scale than previously possible. We show that Tucana experienced three major phases of star formation, two very close together at ancient times and the last one ending between 6 and 8 Gyr ago. We show that the three discrete clumps of stars on the horizontal branch are linked to the distinct episodes of star formation in Tucana. The spatial distribution of the clumps reveals that each generation of stars presents a higher concentration than the previous one. The simultaneous modelling of the horizontal branch and the main sequence turn-off also allows us to measure the amount of mass lost by red giant branch stars in Tucana with unprecedented precision, confirming dwarf spheroidals to be excellent laboratories to study the advanced evolution of low-mass stars.

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The star formation history of the Fornax dwarf spheroidal galaxy

Proceedings of the International Astronomical Union ◽

10.1017/s1743921310003200 ◽

2009 ◽

Vol 5 (S262) ◽

pp. 353-354

Author(s):

Enrico V. Held ◽

Eline Tolstoy ◽

Luca Rizzi ◽

Mary Cesetti ◽

Andrew A. Cole ◽

...

Keyword(s):

Star Formation ◽

Galaxy Evolution ◽

Stellar Population ◽

Main Sequence ◽

Dwarf Galaxy ◽

Star Formation History ◽

Stellar Content ◽

Formation History ◽

First Results ◽

History Of

AbstractWe present the first results of a comprehensive HST study of the star-formation history of Fornax dSph, based on WFPC2 imaging of 7 Fornax fields. Our observations reach the oldest main-sequence turnoffs, allowing us to address fundamental questions of dwarf galaxy evolution, such as the spatial variations in the stellar content, and whether the old stellar population is made up of stars formed in a very early burst or the result of a more continuous star formation.

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The star formation history of the Large Magellanic Cloud star cluster NGC 1751★

Monthly Notices of the Royal Astronomical Society ◽

10.1111/j.1365-2966.2011.18538.x ◽

2011 ◽

Vol 414 (3) ◽

pp. 2204-2214 ◽

Cited By ~ 37

Author(s):

Stefano Rubele ◽

Léo Girardi ◽

Vera Kozhurina-Platais ◽

Paul Goudfrooij ◽

Leandro Kerber

Keyword(s):

Star Formation ◽

Large Magellanic Cloud ◽

Magellanic Cloud ◽

Star Cluster ◽

Star Formation History ◽

Formation History ◽

History Of

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New constraints on the star formation history of the star cluster NGC 1856★

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stv874 ◽

2015 ◽

Vol 450 (3) ◽

pp. 3054-3068 ◽

Cited By ~ 26

Author(s):

Matteo Correnti ◽

Paul Goudfrooij ◽

Thomas H. Puzia ◽

Selma E. de Mink

Keyword(s):

Star Formation ◽

Star Cluster ◽

Star Formation History ◽

Formation History ◽

History Of

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Dwarf Galaxies: From the Epoch of Peak Star Formation to the Epoch of Reionization

Proceedings of the International Astronomical Union ◽

10.1017/s1743921318007494 ◽

2018 ◽

Vol 14 (S344) ◽

pp. 429-436

Author(s):

Hakim Atek

Keyword(s):

Star Formation ◽

Dwarf Galaxies ◽

High Redshift ◽

Great Part ◽

Star Formation History ◽

Dark Matter Halos ◽

Galaxy Surveys ◽

Formation History ◽

History Of ◽

Low Mass

AbstractDwarf galaxies represent the dominant population at high redshift and they most likely contributed in great part to star formation history of the Universe and cosmic reionization. The importance of dwarf galaxies at high redshift has been mostly recognized in the last decade due to large progress in observing facilities allowing deep galaxy surveys to identify low-mass galaxies. This population appear to have extreme emission lines and ionizing properties that challenge stellar population models. Star formation follows a stochastic process in these galaxies, which has important implication on the ionizing photon production and its escape fraction whose measurements are challenging for both simulations and observations. Outstanding questions include: what are the physical properties at the origin of such extreme properties? What are the smallest dark matter halos that host star formation? Are dwarf galaxies responsible for cosmic reionization?

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The star formation history of low-mass disk galaxies: A case study of NGC 300

Astronomy and Astrophysics ◽

10.1051/0004-6361/201527041 ◽

2015 ◽

Vol 585 ◽

pp. A20 ◽

Cited By ~ 5

Author(s):

Xiaoyu Kang ◽

Fenghui Zhang ◽

Ruixiang Chang ◽

Lang Wang ◽

Liantao Cheng

Keyword(s):

Star Formation ◽

Star Formation History ◽

Disk Galaxies ◽

Formation History ◽

History Of ◽

Low Mass

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Dissecting 30 Doradus: Optical and Near Infrared Star Formation History of the starburst cluster NGC2070 from the Hubble Tarantula Treasury Project

Proceedings of the International Astronomical Union ◽

10.1017/s174392131600870x ◽

2015 ◽

Vol 12 (S316) ◽

pp. 77-83

Author(s):

Michele Cignoni ◽

Keyword(s):

Star Formation ◽

Main Sequence ◽

Near Infrared ◽

Mass Function ◽

Large Magellanic Cloud ◽

Initial Mass Function ◽

Star Formation History ◽

Formation History ◽

History Of ◽

30 Doradus

AbstractI will present new results on the star formation history of 30 Doradus in the Large Magellanic Cloud based on the panchromatic imaging survey Hubble Tarantula Treasury Project (HTTP). Here the focus is on the starburst cluster NGC2070. The star formation history is derived by comparing the deepest ever optical and NIR color-magnitude diagrams (CMDs) with state-of-the-art synthetic CMDs generated with the latest PARSEC models, which include all stellar phases from pre-main sequence to post-main sequence. For the first time in this region we are able to measure the star formation using intermediate and low mass stars simultaneously. Our results suggest that NGC2070 experienced a prolonged activity. I will discuss the detailed star formation history, initial mass function and reddening distribution.

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Star cluster disruption

Proceedings of the International Astronomical Union ◽

10.1017/s1743921309990895 ◽

2009 ◽

Vol 5 (S266) ◽

pp. 69-80

Author(s):

Mark Gieles

Keyword(s):

Star Formation ◽

Star Clusters ◽

Star Cluster ◽

Star Formation History ◽

Host Galaxy ◽

Giant Molecular Clouds ◽

Term Survival ◽

Formation History ◽

History Of ◽

External Galaxies

AbstractStar clusters are often used as tracers of major star-formation events in external galaxies as they can be studied out to much greater distances than individual stars. It is vital to understand their evolution if they are used to derive, for example, the star-formation history of their host galaxy. More specifically, we want to know how cluster lifetimes depend on their environment and on structural properties such as mass and radius. This review presents a theoretical overview of the early evolution of star clusters and the consequent long-term survival chances. It is suggested that clusters forming with initial densities of ≳104 M⊙ pc−3 survive the gas expulsion, or ‘infant mortality,’ phase. At ~10Myr, they are bound and have densities of ~103±1 M⊙ pc−3. After this time, they are stable against expansion through stellar evolution, encounters with giant molecular clouds and will most likely survive for another Hubble time if they are located in a moderate tidal field. Clusters with lower initial densities (≲100 M⊙ pc−3) will disperse into the field within a few 10s of Myrs. Some discussion is given on how extragalactic star cluster populations, and especially their age distributions, can be used to gain insight into disruption.

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