114 citations · 742 across the 36 of their papers we have counts for
17 papers · 1 filter
Galactic magnetic X fields
R N Henriksen
Our aim in this note is to compare a recent explanation of the galactic X pattern in Faraday Rotation (XRM), to that produced by the advection part of the classical dynamo.We find…
CHANG-ES XXIII: Influence of a galactic wind in NGC 5775
G. H. Heald, V. Heesen, S. S. Sridhar +22
We present new radio continuum images of the edge-on starburst galaxy NGC 5775, from LOFAR (140 MHz) and the Karl G. Jansky Very Large Array CHANG-ES survey (1500 MHz). We trace th…
CHANG-ES XIV: Cosmic-ray propagation and magnetic field strengths in the radio halo of NGC 4631
Silvia Carolina Mora-Partiarroyo, Marita Krause, Aritra Basu +13
NGC 4631 is an interacting galaxy that exhibits one of the largest, gaseous halos observed among edge-on galaxies. We aim to examine the synchrotron and cosmic-ray propagation prop…
CHANG-ES: XVIII---The CHANG-ES Survey and Selected Results
Judith Irwin, Ancor Damas-Segovia, Marita Krause +8
The CHANG-ES (Continuum Halos in Nearby Galaxies) survey of 35 nearby edge-on galaxies is revealing new and sometimes unexpected and startling results in their radio continuum emis…
Exact spirally symmetric galactic dynamos
R. N. Henriksen, A. Woodfinden, J. A. Irwin
This paper extends the results of an earlier paper on scale invariant galactic spiral magnetic modes to time dependent, scale invariant, spirals. The examples given are all exact i…
Magnetic Spiral Arms in Galaxy Halos
R. N. Henriksen
We seek the conditions for a {\it steady} mean field galactic dynamo. The parameter set is reduced to those appearing in the and dynamo, namely velocity amplitudes, and…
Steady Galactic Dynamos and Observational Consequences I: Halo Magnetic Fields
R. N. Henriksen
We study the global consequences in the halos of spiral galaxies of the steady, axially symmetric, mean field dynamo. We use the classical theory but add the possibility of using t…
CHANG-ES VIII: Uncovering Hidden AGN Activity in Radio Polarization
Judith A. Irwin, Philip Schmidt, A. Damas-Segovia +12
We report on C-band (5 - 7 GHz) observations of the galaxy, NGC~2992, from the CHANG-ES sample. This galaxy displays an embedded nuclear double-lobed radio morphology within its sp…
Magnetized galactic halos and velocity lags
Richard N. Henriksen, Judith A. Irwin
We present an analytic model of a magnetized galactic halo surrounding a Mestel gravitating disc. The magnetic field is taken to be in energy equipartition with the pressure domina…
CHANG-ES V: Nuclear Radio Outflow in a Virgo Cluster Spiral after a Tidal Disruption Event
Judith A. Irwin, Richard N. Henriksen, Marita Krause +5
We have observed the Virgo Cluster spiral galaxy, NGC~4845, at 1.6 and 6 GHz using the Karl G. Jansky Very Large Array, as part of the `Continuum Halos in Nearby Galaxies -- an EVL…
Swinging Spiral Arms
Richard N Henriksen
We study transient spiral structures in an isothermal, thin, galactic disc. We find no instability that can grow everywhere from infinitesimal disturbances, but spiral structure do…
Transient Spiral Arms in Isothermal Stellar Systems
R. N. Henriksen
We begin by recalling the isothermal, collisionless, disc-halo. The disc component is the Mestel disc. Subsequently we introduce spiral arms to such an isothermal disc-halo system…
Continuum Halos in Nearby Galaxies -- an EVLA Survey (CHANG-ES) -- II: First Results on NGC 4631
Judith Irwin, Rainer Beck, R. A. Benjamin +19
We present the first results from the CHANG-ES survey, a new survey of 35 edge-on galaxies to search for both in-disk as well as extra-planar radio continuum emission. The motivati…
Spiral Structure in Scale-free, Thin Discs: Rigid Rotation
R. N. Henriksen
In this paper we suggest the existence in the central regions of spiral galaxies of collisionless, scale-free, rigidly rotating, self-gravitating discs with spiral symmetry. Such d…
Black Holes and Galactic Density Cusps : From Black Hole to Bulge
Morgan Le Delliou, Richard N. Henriksen, Joseph D. Macmillan
Aims. In this paper we continue our study of density cusps that may contain central black holes. Methods. We recall our attempts to use distribution functions with a memory of self…
Black Holes and Galactic Density Cusps Spherically Symmetric Anisotropic Cusps
Morgan Le Delliou, Richard N. Henriksen, Joseph D. Macmillan
Aims: In this paper we study density cusps that may contain central black holes. The actual co-eval self-similar growth would not distinguish between the central object and the sur…
Black holes and Galactic density cusps -- I. Radial orbit cusps and bulges
Morgan Le Delliou, Richard N. Henriksen, Joseph D. Macmillan
In this paper, we study the distribution functions that arise naturally during self-similar radial infall of collisionless matter. Such matter may be thought of either as stars or…