Related papers: Masers in AGN environments
The changes in the spectral line profile of the 22GHz H2O maser are calculated as a function of emerging maser flux. We address not only the narrowing and re-broadening of the maser lines, but also the deviations of Gaussian symmetry as a…
Water megamasers at 22 GHz with a gas disk configuration in galaxies provide the most precise measurements of supermassive black hole masses, as well as independent constraints on the Hubble constant in the nearby universe. The existence of…
In order to understand the evolution and feedback of Active Galactic Nuclei (AGN) and star formation it is important to use molecular lines as probes of physical conditions and chemistry. We use H$_{2}$S to investigate the impact of…
We present the results of an ALMA survey to identify 183 GHz H$_2$O maser emission from AGN already known to host 22 GHz megamaser systems. Out of 20 sources observed, we detect significant 183 GHz maser emission from 13; this survey thus…
We present preliminary results of an interferometric study of the water megamaser in the merger system Arp299. This system is composed of two main sources: IC694 and NGC3690. There is clear evidence that most of the water maser emission is…
In order to identify the dominant nuclear outflow mechanisms in Active Galactic Nuclei, we have undertaken deep, high resolution observations of two compact radio sources (PKS 1549-79 and PKS 1345+12) with the Advanced Camera for Surveys…
We present a new investigation of the dependence of H2O maser detection rates and properties on the mid-IR AGN luminosity, L_AGN, and the obscuring column density, N_H, based on mid-IR and hard X-ray photometry. Based on spectral energy…
Dynamical mechanisms are essential to exchange angular momentum in galaxies, drive the gas to the center, and fuel the central super-massive black holes. While at 100pc scale, the gas is sometimes stalled in nuclear rings, recent…
In these proceedings I briefly: (1) review the impact (or "feedback") that active galactic nuclei (AGN) are predicted to have on their host galaxies and larger scale environment, (2) review the observational evidence for or against these…
Methanol masers are often detected in regions of intense star formation. Several studies in the last decade indicate that they may even be the earliest signpost of a high-mass star-forming region. Their powerful emission make them very good…
The main achievements, current developments and prospects of molecular studies in external galaxies are reviewed. They are put in the context of the results of several decades of studies of molecules in local interstellar medium, their…
Imaging the bright maser emission produced by several molecular species at centimeter wavelengths is an essential tool for understanding the process of massive star formation because it provides a way to probe the kinematics of dense…
OH(1720 MHz) masers permit direct measurements of the magnetic field strength at the Galactic Centre, and their angular broadening constrains models for the medium that scatters radio waves in the central 100 pc of the Galaxy. As the 1720…
The observation of multiple images from a strongly lensed gravitational wave (GW) source provides the observer with a stereoscopic view of the source. This allows for a measure of its relative proper motion by comparing the induced GW…
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…
Various types of active galactic nuclei (AGN) are briefly discussed, with an emphasis on the theory of recent X-ray and $\gamma$-ray observations of the subclass, Seyfert 1 galaxies. The large radiation power from AGN is thought to…
Gravitational waves from neutron star mergers have long been considered a promising way to measure the Hubble constant, $H_0$, which describes the local expansion rate of the universe. While black hole mergers are more abundantly observed,…
Using the Very Large Array, we have detected weak OH maser emission near the Turner-Welch protostellar source in the W3 OH region. Unlike typical interstellar OH masers, which are associated with ultra-compact HII regions, our measured…
The flow of gas into and out of galaxies leaves traces in the circumgalactic medium which can then be studied using absorption lines towards background quasars. We analyse 27 log(N_HI) > 18.0 HI absorbers at z = 0.2 to 1.4 from the…
The cores of active galactic nuclei (AGN) harbor some of the most extreme conditions of matter and energy in the Universe. One of the major goals of high-energy astrophysics is to probe these extreme environments in the vicinity of…