Related papers: Galactic Centre Threads as Nuclear MHD Waves

The Galactic Centre contains a supermassive black hole with a mass of 4 million suns within an environment that differs markedly from that of the Galactic disk. While the black hole is essentially quiescent in the broader context of active…

We revisit the idea that the Galactic center (GC) is the dominant source of Galactic cosmic rays (GCRs), based on a series of new observational evidence. A unified model is proposed to explain the new phenomena of GCRs and $\gamma$-rays…

A detailed understanding of cosmic-ray transport in galactic halos is essential for explaining various observations, such as the radio continuum measurements of synchrotron radiation from energetic electrons. Of central importance is the…

The Circumnuclear Disk (CND) is a torus of dust and moleular gas rotating about the galactic centre and extends from 1.6 to 7pc from the central massive black hole SgrA*. Large Velocity Gradient modelling of selected transitions of HCN…

The center of the Galaxy is a prominent source in X-rays and gamma-rays. The study of its high-energy (HE) emission is crucial in understanding the physical phenomena taking place in this dense and extreme environment, where the closest…

We calculate and analyze the longevity of magnetohydrodynamic (MHD) wave modes that occur in the plane of a magnetic thin sheet. Initial turbulent conditions applied to a magnetically subcritical cloud are shown to lead to relatively rapid…

Spiral galaxies host dynamically important magnetic fields which can affect gas flows in the disks and halos. Total magnetic fields in spiral galaxies are strongest (up to 30 \muG) in the spiral arms where they are mostly turbulent or…

The central 5 parsecs of our Galactic Center is rich in various molecular tracers. The region is observed to be hot, highly ionized, and volatile, resulting in complex chemistry and kinematics. Countless molecular observations of the…

The evidence for the presence of a concentration of dark matter at the Galactic center is now very compelling. There is no question that the stellar and gas kinematics within 0.01 pc is dominated by under-luminous matter in the form of…

Fast-mode magnetohydrodynamic (MHD) waves in the solar corona are often known to be produced by solar flares and eruptive prominences. We here simulate the effect of the interaction of an external perturbation on a magnetic null in the…

We propose that the recent observations reported by the different Pulsar Timing Array (PTA) collaborations (i.e.~IPTA, EPTA, PPTA, and NANOGrav) of a common process over several pulsars could correspond to a stochastic gravitational wave…

Multi-frequency radio polarimetry of the diffuse Galactic synchrotron background gives new viewpoints on the Galactic magnetic field. Rotation measure maps reveal magnetic structures on arcminute to degree scales, such as a ring in…

During structure formation, energetic events and random motions of the hot gas residing inside galaxy clusters (the intracluster medium, ICM) generate turbulent motions. Radio diffuse emission probes the presence of magnetic fields and…

We have used the BIMA array to image the Galactic Center with a 19-pointing mosaic in HCN(1-0), HCO+(1-0), and H 42-alpha emission with 5 km/s velocity resolution and 13'' x 4'' angular resolution. The 5' field includes the circumnuclear…

Radio observations of galaxy clusters show that the intra cluster medium is permeated by \mu G magnetic fields. The origin and evolution of these cosmological magnetic fields is currently not well understood and so their impact on the…

We examine in detail the detectability of a signal of diffuse high energy neutrinos produced in the Milky Way by the interaction of cosmic rays (CRs) with the interstellar medium (ISM). We show that highly inhomogeneous galactic CR…

It is demonstrated through a succinct derivation as to how the linear waves in Hall magnetohydrodynamics (HMHD) constitute a fundamental departure from the standard MHD waves. Apart from modifying the conventional MHD spectrum, the Hall…

Observations are consistent with a significant fraction of heavy nuclei in the cosmic ray flux above a few times 10^19 eV. Such nuclei can be deflected considerably in the Galactic magnetic field, with important implications for the search…

Electromagnetic observations over the last 15 years have yielded a growing appreciation for the importance of supermassive black holes (SMBH) to the evolution of galaxies, and for the intricacies of dynamical interactions in our own…

New observations of Sgr A have been carried out with the VLA using the broadband (2 GHz) continuum mode at 5.5 GHz, covering the central 30 pc region of the RBZ at the Galactic center. Using the MS-MFS algorithms in CASA, we have imaged Sgr…