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Related papers: Recent Developments in Maser Theory

200 papers

We present a survey of OH maser emission towards a sample of high mass protostellar objects made using the Nancay and GBT telescopes.OH maser emission was detected towards 63 objects with 36 new detections. There are 56 star-forming regions…

Astrophysics · Physics 2009-11-13 K. A. Edris , G. A. Fuller , R. J . Cohen

Through polarization observations masers are unique probes of the magnetic field in a variety of different astronomical objects, with the different maser species tracing different physical conditions. In recent years maser polarization…

Astrophysics · Physics 2009-11-13 W. H. T. Vlemmings

The theory of magnetically accelerated outflows and jets from accretion disks is reviewed at an introductory level, with special attention to problem areas like the launching conditions of the flow at the disk surface, stability of the…

Astrophysics · Physics 2007-05-23 H. C. Spruit

As the recent publication by Breen et al (2013) found Class II methanol masers are exclusively associated with high mass star forming regions. Based on the positions of the Class I and II methanol and H$_{2}$O masers, UC H II regions and…

Astrophysics of Galaxies · Physics 2014-11-19 Hontas Farmer

Context. Maser emission is a strong tool for studying high mass star forming regions and their evolutionary stages. OH masers in particular can trace the circumstellar material around protostars and determine their magnetic field strengths…

Astrophysics of Galaxies · Physics 2017-12-13 K. A. Edris , G. A. Fuller , S. Etoka , R. J. Cohen

High-angular resolution observations at sub-millimeter/millimeter wavelengths of disks surrounding young stars have shown that their morphology is made of azimuthally-symmetric or point-symmetric substructures, in some cases with spiral…

Earth and Planetary Astrophysics · Physics 2021-10-27 Diana Blanco , Luca Ricci , Mario Flock , Neal Turner

Methanol masers which are traditionally divided into two classes provide possibility to study important parts of the star forming regions: Class~II masers trace vicinities of the massive YSOs while class~I masers are likely to trace more…

I review the processes that shape the evolution of protoplanetary discs around young, solar-mass stars. I first discuss observations of protoplanetary discs, and note in particular the constraints these observations place on models of disc…

Astrophysics · Physics 2008-11-26 Richard Alexander

Observations show that 1612 MHz masers of OH/IR stars can fade on a timescale of a decade. This fading is probably associated with the switch from rapid mass loss, which is ultimately linked with an internal He-shell flash, to the much…

Astrophysics · Physics 2009-11-13 M. D. Gray D. A. Howe , B. M. Lewis

As part of the Megamaser Cosmology Project (MCP), we present VLBI maps of nuclear water masers toward five galaxies. The masers originate in sub-parsec circumnuclear disks. For three of the galaxies, we fit Keplerian rotation curves to…

These notes review theoretical models of massive black hole formation, growth and observables. They start with a brief summary of basic properties of massive black hole properties. The current view on massive black holes and active galactic…

Astrophysics of Galaxies · Physics 2025-10-07 Marta Volonteri

We present a review of the most recent improvements in the theory of low-mass star-like objects, in the stellar and sub-stellar domains. Comparison is made with various recent observations.

Astrophysics · Physics 2007-05-23 Gilles Chabrier , Isabelle Baraffe

Massive black holes are fundamental constituents of our cosmos, from the Big Bang to today. Understanding their formation from cosmic dawn, their growth, and the emergence of the first, rare quasars in the early Universe remains one of our…

High Energy Astrophysical Phenomena · Physics 2023-04-25 Tiziana Di Matteo , Daniel Angles-Alcazar , Francesco Shankar

We present full resolution (~0.2mas, ~0.1 A.U.) Very Long Baseline Interferometry maps of the v=1, J=1-0 SiO masers in the Orion-KL nebula. The morphology and turbulent nature of the maser emission argues against models in which the masers…

Astrophysics · Physics 2007-05-23 Sheperd Doeleman Colin Lonsdale Shannon Pelkey

The near infrared (1-2um) and the thermal infrared (3-25um) trace many of the environments in which masers are thought to reside, including shocks, outflows, accretion disks, and the dense medium near protostars. After a number of recent…

Astrophysics · Physics 2009-11-13 James De Buizer

Recent developments in the spectropolarimetric study of compact objects, specifically black holes (stellar and massive) and neutron stars are reviewed. The lectures are organized around five topics: disks, jets, outflows, neutron stars and…

Astrophysics · Physics 2007-05-23 Roger Blandford , Eric Agol , Avery Broderick , Jeremy Heyl , Leon Koopmans , Hee-Won Lee

The hypothesis of existence of primordial black holes with large masses (\geq 10^6 M\odot), formed at the earliest stages of the Universe evolution, is considered in the paper. The possibility does not contradict some theories, see e.g.…

Cosmology and Nongalactic Astrophysics · Physics 2013-09-17 V. K. Dubrovich , S. I. Glazyrin

The existence of supermassive black holes is supported by a growing body of observations. Supermassive black holes and their formation events are likely candidates for detection by proposed long-wavelength, space-based gravitational wave…

Astrophysics · Physics 2009-10-31 Kimberly C. B. New , Stuart L. Shapiro

We give a brief overview of where we stand with respect to some old and new questions bearing on how massive stars evolve and end their lifetime. We focus on the following key points that are further discussed by other contributions during…

Solar and Stellar Astrophysics · Physics 2017-11-15 Georges Meynet , André Maeder , Cyril Georgy , Sylvia Ekström , Patrick Eggenberger , Fabio Barblan , Han Feng Song

The ATCA has been used to measure positions with arcsecond accuracy for 379 masers at the 22-GHz transition of water. The principal observation targets were 202 OH masers of the variety associated with star formation regions (SFR)s in the…

Astrophysics of Galaxies · Physics 2015-05-18 Shari Breen , James Caswell , Simon Ellingsen , Chris Phillips