The Starburst Irregular Dwarf Galaxy

The Starburst Irregular Dwarf Galaxy PDF Author: Wu Zhongqi
Publisher:
ISBN:
Category :
Languages : en
Pages : 110

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The Starburst Irregular Dwarf Galaxy

The Starburst Irregular Dwarf Galaxy PDF Author: Wu Zhongqi
Publisher:
ISBN:
Category :
Languages : en
Pages : 110

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Book Description


The Starburst Irregular Dwarf Galaxy HE 2-10

The Starburst Irregular Dwarf Galaxy HE 2-10 PDF Author: Wu Zhongqi
Publisher:
ISBN:
Category : Galaxies
Languages : en
Pages : 111

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NGC 1569 - the ISM of a Dwarf Galaxy in the Aftermath of a Starburst

NGC 1569 - the ISM of a Dwarf Galaxy in the Aftermath of a Starburst PDF Author: Stefanie Mühle
Publisher: Cuvillier Verlag
ISBN: 9783898739597
Category : Dwarf galaxies
Languages : en
Pages : 179

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On the Prevalence of Starbursts in Dwarf Galaxies

On the Prevalence of Starbursts in Dwarf Galaxies PDF Author: Janice Christine Lee
Publisher:
ISBN:
Category :
Languages : en
Pages : 400

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Book Description
An outstanding question in galaxy evolution research is whether the star formation histories of low mass systems are dominated by global starbursts or modes that are more quiescent and continuous. In this thesis, we quantify the prevalence of global starbursts in dwarf galaxies at the present epoch, and attempt to infer their characteristic durations, frequencies and amplitudes in the past. Our approach is to directly tally the number of bursting dwarfs in a complete local sample, and to compute the fraction of star formation that is concentrated in these systems. The resulting starburst number and mass fractions are then combined with B-V colors from the literature, the H-alpha EWs presented here, and stellar evolutionary synthesis models in order to place constraints on the average starburst duty cycle. The primary dataset used has been put together by the 11 Mpc H-alpha UV Galaxy Survey, who have collected data on an approximately volume-limited, statistical sample of star-forming galaxies within 11 Mpc of the Milky Way. Our main observational results, along with the accumulation of star formation studies of dwarf galaxies over the past three decades, paint a consistent picture where systems that are currently experiencing a massive global burst are just the 6% +/- 3% tip of a low-mass galaxy iceberg. Moreover, bursts are responsible for 22% +/- 10% of the total star formation in the overall dwarf galaxy population, so the majority of stars in low-mass systems do not appear to be formed in this mode today. Over their lifetimes, however, a greater fraction of the stellar mass of a dwarf may be formed in the burst mode. Synthesis modeling suggests that bursts cycles appear to be necessary in order to simultaneously explain the present-day observed blue B-V colors and modest H-alpha EWs of TYPICAL, CURRENTLY NON-BURSTING dwarf irregulars, unlessnon-standard assumptions concerning the IMF and the escape fractions of Lyman continuum photons are made. The starburst cycle that we converge upon involves burst durations of 50-100 Myrs, cycle frequencies of 1 to 3 per Gyr, and elevated burst SFRs that are a factor of 6-10 higher than the rate in the quiescent state. Galaxies characterized by such a SFH would spend 1̃0% of their lives in the burst state, and form 5̃0% of their stellar mass during this time.

Dwarf Galaxies: Keys to Galaxy Formation and Evolution

Dwarf Galaxies: Keys to Galaxy Formation and Evolution PDF Author: Polychronis Papaderos
Publisher: Springer Science & Business Media
ISBN: 3642220185
Category : Science
Languages : en
Pages : 347

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Book Description
Dwarf galaxy research constitutes an extremely vibrant field of astrophysical research, with many long-standing questions still unsettled and new ones constantly arising. The intriguing diversity of the dwarf galaxy population, observed with advanced ground-based and space-borne observatories over a wide spectral window providing an unprecedented level of detail, poses new challenges for both observers and theoreticians. The aim of this symposium was to bring together these two groups to exchange ideas and new results on the many evolutionary aspects of and open issues concerning dwarf galaxies. The main topics addressed include: the birth of dwarf galaxies: theoretical concepts and observable relics across wavelengths and time, the morphological, structural and chemical evolution of dwarf galaxies, possible evolutionary connections between early-type and late-type dwarfs, the star formation history of dwarf galaxies and its dependence on intrinsic and environmental properties, the origin and implications of starburst activity in dwarf galaxies, the fate of dwarfish systems born out of tidally ejected matter in galaxy collisions.

Starbursts in Dwarf Galaxies

Starbursts in Dwarf Galaxies PDF Author: John Michael Cannon
Publisher:
ISBN:
Category :
Languages : en
Pages : 448

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Starbursts

Starbursts PDF Author: Richard de Grijs
Publisher: Springer Science & Business Media
ISBN: 140203539X
Category : Science
Languages : en
Pages : 390

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Book Description
Starbursts are important features of early galaxy evolution. Many of the distant, high-redshift galaxies we are able to detect are in a starbursting phase, often apparently provoked by a violent gravitational interaction with another galaxy. In fact, if we did not know that major starbursts existed, these conference proceedings testify that we would indeed have difficulties explaining the key properties of the Universe! These conference proceedings cover starbursts from the small-scale star-forming regions in nearby galaxies to galaxy-wide events at high redshifts; one of the major themes of the conference proved to be "scalability", i.e., can we scale up the small-scale events to describe the physics on larger scales. The key outcome of this meeting – and these proceedings – is a resounding "yes" to this fundamental, yet profound question. The enhanced synergy facilitated by the collaboration among observers using cutting-edge ground and space-based facilities, theorists and modellers has made these proceedings a true reflection of the state of the art in this very rapidly evolving field.

Star Formation in Dwarf Irregular Galaxies

Star Formation in Dwarf Irregular Galaxies PDF Author: Robbie Christopher Dohm-Palmer
Publisher:
ISBN:
Category :
Languages : en
Pages : 350

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Stellar Disk Evolution and Gaseous Disk Turbulence of Dwarf Irregular Galaxies

Stellar Disk Evolution and Gaseous Disk Turbulence of Dwarf Irregular Galaxies PDF Author: Hong-Xin Zhang
Publisher: Springer
ISBN: 3662528673
Category : Science
Languages : en
Pages : 179

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Book Description
This book focuses on the stellar disk evolution and gas disk turbulence of the most numerous galaxies in the local Universe – the dwarf galaxies. The “outside-in” disk shrinking mode was established for a relatively large sample of dwarf galaxies for the first time, and this is in contrast to the “inside-out” disk growth mode found for spiral galaxies. Double exponential brightness profiles also correspond to double exponential stellar mass profiles for dwarf galaxies, which is again different from most spiral galaxies. The cool gas distribution in dwarf galaxies was probed with the spatial power spectra of hydrogen iodide (HI) gas emission, and provided indirect evidence that inner disks of dwarf galaxies have proportionally more cool gas than outer disks. The finding that no correlation exists between gas power spectral indices and star formation gave important constraints on the relation between turbulence and star formation in dwarf galaxies.

Extragalactic Astronomy and Cosmology

Extragalactic Astronomy and Cosmology PDF Author: Peter Schneider
Publisher: Springer
ISBN: 364254083X
Category : Science
Languages : en
Pages : 637

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Book Description
This second edition has been updated and substantially expanded. Starting with the description of our home galaxy, the Milky Way, this cogently written textbook introduces the reader to the astronomy of galaxies, their structure, active galactic nuclei, evolution and large scale distribution in the Universe. After an extensive and thorough introduction to modern observational and theoretical cosmology, the focus turns to the formation of structures and astronomical objects in the early Universe. The basics of classical astronomy and stellar astrophysics needed for extragalactic astronomy are provided in the appendix. While this book has grown out of introductory university courses on astronomy and astrophysics and includes a set of problems and solutions, it will not only benefit undergraduate students and lecturers; thanks to the comprehensive coverage of the field, even graduate students and researchers specializing in related fields will appreciate it as a valuable reference work.