Download or read book Dense Molecular Gas around Protostars and in Galactic Nuclei written by Willem A. Baan and published by Springer Science & Business Media. This book was released on 2005-12-05 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt: These proceedings summarize our present knowledge on astronomical molecules, highlight major problems to be addressed, and finally propose future work. Their theoretical understanding involves physics, numerical simulations and chemistry.
Download or read book Dense Molecular Gas Around Protostars and in Galactic Nuclei written by Willem A. Baan and published by . This book was released on 2005 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Atacama Large Millimeter Submillimeter Array View of Molecular Gas in Brightest Cluster Galaxies written by Adrian Vantyghem and published by . This book was released on 2018 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis I use ALMA observations to map the distribution and kinematics of molecular gas in the brightest cluster galaxies of three galaxy clusters: 2A0335+096, RXJ0821+0752, and RXCJ1504-0248. The goal is to understand how the coldest gas in clusters is formed, identify any long-lived structures that could fuel sustained black hole accretion, and explore star formation in cluster environments. I use the J=1-0 and J=3-2 rotational transitions of carbon monoxide (CO) as tracers of the total molecular gas distribution. The two transitions provide different resolutions and fields of view. The molecular gas in all three central galaxies are complex and disturbed. None show evidence for rotationally-supported nuclear structures, such as a disk or ring, that would be expected from either a merger origin or long-lived cooling flow. Instead, the molecular gas is either clumpy with no clear velocity structure or extends away from the galactic center in filaments that are several kiloparsecs long. The molecular filaments are coincident with nebular and bright X-ray emission, suggesting that they have condensed out of the hot intracluster medium. They are also generally associated with cavities in the X-ray emission inflated by the active galactic nucleus (AGN), suggesting that AGN feedback has stimulated the formation of molecular gas. The narrow velocity gradients along the filaments are only consistent with freefall if the filament is situated close to the plane of the sky. This is a common feature in brightest cluster galaxies. Since ram pressure is ineffective at slowing dense molecular clouds, the filaments must either be pinned to the hot atmosphere by magnetic fields or have condensed in-situ relatively recently. In RXCJ1504-0248 I combine the ALMA analysis with spatially-resolved ultraviolet emission tracing young stars. The central gas falls on the Kennicutt-Schmidt relation, while the filament has elevated star formation surface densities. The ongoing consumption of a finite fuel supply by star formation, or spatial variations in the CO-to-H2 conversion factor, may be diminishing the molecular gas surface density to produce this effect. Despite their drastic differences in morphology and environment, the molecular gas in clusters is still converted into stars following the same relation as in spirals and starbursts. I have also detected the J=3-2 transition from 13CO, an optically thin isotopologue of 12CO, in RXJ0821.0+0752. This enables a measurement of the conversion between CO intensity and molecular column density for the first time in a galaxy cluster. The CO-to-H2 conversion factor in RXJ0821+0752 is half of the Galactic value. If this value applies to other clusters, then it would alleviate the high coupling efficiencies required for molecular filaments to be uplifted by X-ray cavities. This analysis also provides reassurance that the molecular gas masses measured in BCGs are unlikely to be overwhelmingly biased by adopting the Galactic conversion factor.
Download or read book Molecular Gas in Nearby Active Galactic Nuclei written by Andrew Jordan Baker and published by . This book was released on 2000 with total page 362 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advances in Astronomy written by J. M. T. Thompson and published by World Scientific. This book was released on 2005 with total page 434 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Derived in part from work originally published in the Philosophical Transactions of the Royal Society, series A (Phil. Trans. R. Soc. A, 360, 2649-3004, 2002)."--t.p.
Download or read book Mapping Extragalactic Dense Molecular Gas written by Molly J. Gallagher and published by . This book was released on 2019 with total page 181 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gas density plays an important role in galactic evolution via its connection to star formation. Yet because dense gas is difficult to observe, we are only beginning to explore how interstellar gas density and its relationship to the star formation rate (SFR) depend on galactic environment. My thesis presents three comparisons between gas density, SFR, and galactic environment in nearby spiral galaxies.
Download or read book Molecular Gas in Dwarf Galaxies written by Adam Kirby Leroy and published by . This book was released on 2006 with total page 578 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Big Bang Active Galactic Nuclei and Supernovae Paper written by S. Hayakawa and published by . This book was released on 1989 with total page 642 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Kapteyn Astronomical Institute Annual Report written by and published by . This book was released on 2006 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dense Molecular Gas in Galaxies and the Evolution of Luminous Infrared Galaxies written by Yu Gao and published by . This book was released on 1996 with total page 492 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Astronomy and Astrophysics Abstracts written by S. Böhme and published by Springer Science & Business Media. This book was released on 2013-12-14 with total page 1180 pages. Available in PDF, EPUB and Kindle. Book excerpt: From the reviews: Astronomy and Astrophysics Abstracts has appeared in semi-annual volumes since 1969 and it has already become one of the fundamental publications in the fields of astronomy, astrophysics and neighbouring sciences. It is the most important English-language abstracting journal in the mentioned branches. ... The abstracts are classified under more than hundred subject categories, thus permitting a quick survey of the whole extended material. The AAA is a valuable and important publication for all students and scientists working in the fields of astronomy and related sciences. As such it represents a necessary ingredient of any astronomical library all over the world." Space Science Reviews #1 "Dividing the whole field plus related subjects into 108 categories, each work is numbered and most are accompanied by brief abstracts. Fairly comprehensive cross-referencing links relevant papers to more than one category, and exhaustive author and subject indices are to be found at the back, making the catalogues easy to use. The series appears to be so complete in its coverage and always less than a year out of date that I shall certainly have to make a little more space on those shelves for future volumes." The Observatory Magazine #1
Download or read book Molecular Gas and Star Formation in Nearby Galaxies written by Dyas Utomo and published by . This book was released on 2017 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the local Universe, stars form within molecular clouds. Therefore, the properties of molecular clouds may determine the star formation rate. Conversely, star formation also gives feedback to the clouds where the stars reside. In this dissertation, I present the interplay between the molecular gas and star formation, through three parts below. First, I identify and characterize the properties of molecular clouds in NGC4526, resulting in the first catalog of molecular clouds in an early-type galaxy. As a population, the molecular clouds in NGC4526 are gravitationally bound and have a steeper mass distribution than that in the Milky Way. These molecular clouds are also more luminous, denser, and have a higher velocity dispersion than their counterparts in the Milky Way. These different properties may be due to a more intense interstellar radiation field than in the Galactic disk and a weaker external pressure than in the Galactic center. Second, I combine the mm-wave interferometric data from CARMA and the optical Integral Field Unit data from CALIFA to study the molecular depletion time on kilo-parsec scales of nearby galaxies. In particular, the molecular depletion time between the galactic centers and disks is compared. I find that some galactic centers have shorter depletion time than that in the disks, which means that those centers form stars more efficiently per unit molecular gas mass. This places the galactic centers as an intermediate regime between galactic disks and starburst galaxies. The central drop of depletion time is also correlated with a central increase in the stellar mass surface density, suggesting that a shorter depletion time is associated with the molecular gas compression by the stellar gravitational potential. Third, the feedback from star formation to maintain turbulence in the interstellar matter of M33 is investigated. I show that supernovae have enough energy to maintain atomic gas turbulence inside 4 kpc radius and within molecular clouds, assuming a constant value of turbulent dissipation time of 9.8 Myrs. In the outer parts, the energy from the differential rotation of galaxy is large enough to maintain atomic gas turbulence through the magneto-rotational instability (MRI). I conclude that the sum of supernovae and MRI energy maintains turbulence at all radii where atomic hydrogen is detected in M33.
Download or read book Physics of Star Formation in Galaxies written by F. Palla and published by Springer Science & Business Media. This book was released on 2006-07-06 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book begins with a historical introduction, "Star Formation: The Early History", that presents new material of interest for students and historians of science. This is followed by two long articles on "Pre-Main-Sequence Evolution of Stars and Young Clusters" and "Observations of Young Stellar Objects". These articles on the fascinating problem of star formation from interstellar matter give a thorough overview of present-day theories and observations. The articles contain material so far unpublished in the astronomical literature. The book addresses graduate students and can be used as a textbook for advanced courses in stellar astrophysics.
Download or read book Encyclopedia of Astronomy Astrophysics written by P Murdin and published by CRC Press. This book was released on 2001-01-01 with total page 5610 pages. Available in PDF, EPUB and Kindle. Book excerpt: In a unique collaboration, Nature Publishing Group and Institute of Physics Publishing have published the most extensive and comprehensive reference work in astronomy and astrophysics. This unique resource covers the entire field of astronomy and astrophysics and this online version includes the full text of over 2,750 articles, plus sophisticated search and retrieval functionality and links to the primary literature. The Encyclopaedia's authority is assured by editorial and advisory boards drawn from the world's foremost astronomers and astrophysicists. This first class resource is an essential source of information for undergraduates, graduate students, researchers and seasoned professionals, as well as for committed amateurs, librarians and lay people wishing to consult the definitive astronomy and astrophysics reference work.
Download or read book Structure and Evolution of Active Galactic Nuclei written by G. Giuricin and published by Springer. This book was released on 1986-01-31 with total page 808 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of International Meeting held in Trieste, Italy, April 10-13, 1985
Download or read book The Formation of Stars written by Steven W. Stahler and published by John Wiley & Sons. This book was released on 2008-07-11 with total page 865 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a comprehensive treatment of star formation, one of the most active fields of modern astronomy. The reader is guided through the subject in a logically compelling manner. Starting from a general description of stars and interstellar clouds, the authors delineate the earliest phases of stellar evolution. They discuss formation activity not only in the Milky Way, but also in other galaxies, both now and in the remote past. Theory and observation are thoroughly integrated, with the aid of numerous figures and images. In summary, this volume is an invaluable resource, both as a text for physics and astronomy graduate students, and as a reference for professional scientists.
Download or read book The Central Engine of Active Galactic Nuclei written by Luis C. Ho and published by . This book was released on 2007 with total page 830 pages. Available in PDF, EPUB and Kindle. Book excerpt:
