Download or read book A Multi Wavelength Study of the Star Formation Processes in the W3 Giant Molecular Cloud written by Danae Polychroni and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Multi Wavelength Study of the Star Formation Process in the W3 Giant Molecular Cloud written by Danae Polychroni and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Multiwavelength Study of the Process of High mass Star Formation written by Eric M. Howard and published by . This book was released on 1996 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Star Formation in the Auriga California Giant Molecular Cloud and Its Circumstellar Disk Population written by Hannah Broekhoven-Fiene and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents a multiwavelength analysis, from the infrared to the microwave, of the young, forming stars in the Auriga-California Molecular Cloud and a first look at the disks they host and their potential for forming planetary systems. At the beginning of this thesis, Auriga-Cal had only recently been identified as one contiguous cloud with its distance placing it within the Gould Belt of nearby star-forming regions (Lada et al. 2009). This thesis presents the largest body of work to date on Auriga-Cal's star formation and disk population. Auriga-Cal is one of two nearby giant molecular clouds (GMCs) in the Gould Belt, the other being the Orion A molecular cloud. These two GMCs have similar mass (~10^5 Msolar), spatial scale (~80 pc), distance (~450 pc), and filamentary morphology, yet the two clouds present very different star formation qualities and quantities. Namely, Auriga-Cal is forming far fewer stars and does not exhibit the high-mass star formation seen in Orion A. In this thesis, I present a census of the star forming objects in the infrared with the Spitzer Space Telescope showing that Auriga-Cal contains at least 166 young stellar objects (YSOs), 15-20x fewer stars than Orion A, the majority of which are located in the cluster around LkHalpha 101, NGC 1529, and the filament extending from it. I find the submillimetre census with the James Clerk Maxwell Telescope, sensitive to the youngest objects, arrives at a similar result showing the disparity between the two clouds observed in the infrared continues to the submillimetre. Therefore the relative star formation rate between the two clouds has remained constant in recent times. The final chapter introduces the first study targeted at the disk population to measure the formation potential of planetary systems around the young stars in Auriga-Cal. The dust thermal emission at cm wavelengths is observed to measure the relative amounts of cm-sized grains, indicative of the grain growth processes that take place in disks and are necessary for planet formation. For a subsample of our targets, we are able to measure the spectral slope in the cm to confirm the thermal nature of the observed emission that we detect and characterize the signature of grain growth. The sensitivity of our observations probes masses greater than the minimum mass solar nebula (MMSN), the disk mass required to form the Solar System. We detect 19 disks, representing almost a third of our sample, comparable to the numbers of disks in other nearby star-forming regions with disks masses exceeding the MMSN, suggesting that the disk population in Auriga-Cal possesses similar planet formation potential as populations in other clouds. Confirmation of this result requires future observations with mm interferometry, the wavelength regime where the majority of statistics of disks has been measured.
Download or read book The Physics of Star Formation and Early Stellar Evolution written by Charles J. Lada and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 779 pages. Available in PDF, EPUB and Kindle. Book excerpt: The origin of stars is one of the principle mysteries of nature. During the last two decades advances in technology have enabled more progress to be made in the quest to understand stellar origins than at any other time in history. The study of star formation has developed into one of the most important branches of mod ern astrophysical research. A large body of observational data and a considerable literat ure now exist concerning this topic and a 1arge community of international astronomers and physicists devote their efforts attempting to decipher the secrets of stellar birth. Yet, the young astronomerjphysicist or more advanced researcher desiring to obtain a basic background in this area of research must sift through a very diverse and sometimes bewildering literature. A literature which includes research in many discip1ines and sub discip1ines of classical astrophysics from stel lar structure to the interstellar medium and encompasses the entire range of the electromagnetic spectrum from radio to gamma rays. Often, the reward of a suc cessfu1 foray through the current literature is the realization that the results can be obsolete and outdated as soon as the ink is dry in the journal or the conference proceeding in which they are published.
Download or read book Star Formation in Molecular Clouds written by Nalin Vutisalchavakul and published by . This book was released on 2015 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt: There has been many recent observations in the area of star formation. High-resolution observations of other galaxies enabled a study of extragalactic star formation in more detailed while large scale surveys of the Milky Way enabled a more comprehensive study of Galactic star formation. The main goal of this thesis is to use multi-wavelength, large-scale observations of the Milky Way to connect Galactic to extragalactic star formation and to study star formation regulation in molecular clouds. We tested the use of extragalactic star formation rate tracers on nearby molecular clouds and found that the total infrared and 24 [mu]m luminosity underestimate star formation rates of nearby molecular clouds by a large factor, indicating a problem of using extragalactic tracers of star formation on small regions and regions with low mass or low star formation rates. We studied the relation between star formation and molecular gas distribution in a 11 square degree of the Galactic Plane on various spatial scales starting from a clump scale of around few parsecs to a scale of ≈ 200 parsec. The result shows a good correlation between molecular gas and star formation on a scale above ≈ 5 -- 8'. The star formation relation that is seen on disk-averaged scales in other galaxies shows a large scatter on the small scales. We built a catalog of Galactic molecular clouds with measured star formation rates and studied the relations between properties of molecular clouds and star formation. We tested several models of star formation on the catalog of molecular clouds. We found that the dense gas mass shows significant correlations with star formation rates but the depletion time of dense gas varies with other properties of the clouds. We found that the free- fall efficiency is higher in dense gas compared to the general molecular gas of the clouds.
Download or read book Triggered and Spontaneous Star Formation in the W3 Giant Molecular Cloud written by James Allsopp and published by . This book was released on 2012 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Molecular Clouds and Star Formation written by Melissa Lanae Enoch and published by . This book was released on 2008 with total page 624 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Multiwavelength Study of Two High mass Star forming Regions written by Virginie Aline Montes and published by . This book was released on 2018 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Linking the Formation of Molecular Clouds and High mass Stars written by Quang Nguyen Luong and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Multi wavelength Study of the Star forming Region G333 6 0 2 written by Takuya Fujiyoshi and published by . This book was released on 1999 with total page 358 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Multi wavelength Study of Early Star forming Galaxies written by and published by . This book was released on 2011 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Star Formation in Galaxy Evolution Connecting Numerical Models to Reality written by Nickolay Y. Gnedin and published by Springer. This book was released on 2015-09-09 with total page 375 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains the elaborated and updated versions of the 24 lectures given at the 43rd Saas-Fee Advanced Course. Written by four eminent scientists in the field, the book reviews the physical processes related to star formation, starting from cosmological down to galactic scales. It presents a detailed description of the interstellar medium and its link with the star formation. And it describes the main numerical computational techniques designed to solve the equations governing self-gravitating fluids used for modelling of galactic and extra-galactic systems. This book provides a unique framework which is needed to develop and improve the simulation techniques designed for understanding the formation and evolution of galaxies. Presented in an accessible manner it contains the present day state of knowledge of the field. It serves as an entry point and key reference to students and researchers in astronomy, cosmology, and physics.
Download or read book A Multi wavelength Spectroscopic and Photometric Study of Star Formation and Dust in Galaxies in the Early Universe written by Irene Shivaei and published by . This book was released on 2017 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: Redshift of z
Download or read book Observational Studies of Fragmentation in Molecular Clouds written by Riwaj Pokhrel and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In this dissertation, I explore fragmentation physics in multiple scales in nearby molecular clouds and discuss some implications of fragmentation for cloud structure formation and star formation, primarily by analyzing multi-wavelength observations of dust emission. First, I tested the complete thermal and combined thermal and nonthermal support mechanisms that balance gravitational contraction at multiple scales in the Perseus molecular cloud. I found that the observed multiscale structures in Perseus are consistent with an inefficient thermal Jeans fragmentation, where the Jeans efficiency increases from the largest scale ($\gtrsim$10s of pc) to the smallest scale ($\sim$10s of AU). Next, I studied the effect of the formation of dense self-gravitating structures and star formation on the gas distribution in terms of its column density distribution function (N-PDF). I found that the evolutionary effect of clouds has corresponding changes on the N-PDF functional form, with a lognormal shape in diffuse regions that have negligible star formation, a lognormal and two power-laws in denser regions with moderate star formation, and a lognormal and one power-law in the densest regions with highly efficient clustered star formation. Finally, I explored the variations of star and gas surface densities in twelve molecular clouds using various techniques. I found that the stellar mass surface density of the recently formed stars varies as the square of the gas mass surface density in all twelve clouds. Also, I do not find any evidence of a column density threshold for efficient star formation.
Download or read book The Earliest Stages of Massive Clustered Star Formation Fragmentation of Infrared Dark Clouds written by Ke Wang and published by Springer. This book was released on 2016-08-11 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents an in-depth, high-resolution observational study on the very beginning of the formation process: the fragmentation of dense molecular clouds known as infrared dark clouds (IRDCs). Using the Submillimeter Array (SMA) and Very Large Array (VLA) radio interferometers, the author has discovered a common picture of hierarchical fragmentation that challenges some of the leading theoretical models and suggests a new, observation-driven understanding of how massive star formation in clustered environments may begin: it is initiated by the hierarchical fragmentation of a dense filament from 10 pc down to 0.01 pc, and the stellar mass buildup is simultaneously fed by hierarchical accretion at similar scales. The new scenario points out the importance of turbulence and filamentary structure, which are now receiving increasing attention and further tests from both observers and theorists.
Download or read book Star Formation in Giant Molecular Clouds written by Daniel Thomas Jaffe and published by . This book was released on 1980 with total page 221 pages. Available in PDF, EPUB and Kindle. Book excerpt:
