Time-variability of the Crab Nebula wisps
نویسندگان
چکیده
منابع مشابه
A Model for the Moving ‘wisps’ in the Crab Nebula
I propose that the moving ‘wisps’ near the center of the Crab Nebula result from nonlinear KelvinHelmholtz instabilities in the equatorial plane of the shocked pulsar wind. Recent observations suggest that the wisps trace out circular wavefronts in this plane, expanding radially at speeds<∼ c/3. Instabilities could develop if there is sufficient velocity shear between a faster-moving equatorial...
متن کاملObservations of “wisps” in magnetohydrodynamic simulations of the Crab Nebula
In this letter, we describe results of new high-resolution axisymmetric relativistic MHD simulations of Pulsar Wind Nebulae. The simulations reveal strong breakdown of the equatorial symmetry and highly variable structure of the pulsar wind termination shock. The synthetic synchrotron maps, constructed using a new more accurate approach, show striking similarity with the well known images of th...
متن کاملNear-infrared, Kilosecond Variability of the Wisps and Jet in the Crab Pulsar Wind Nebula
We present a time-lapse sequence of 20 near-infrared (J and K 0 band) snapshots of the central 20 ; 20 of the Crab pulsar wind nebula, taken at subarcsecond resolution with the Hokupa‘a /QUIRC adaptive optics camera on the Gemini North Telescope and sampled at intervals of 10 minutes and 24 hr. It is observed that the equatorial wisps and polar knots in the termination shock of the pulsar wind ...
متن کاملTime-dependence in Relativistic Collisionless Shocks: Theory of the Variable “wisps” in the Crab Nebula
We describe results from time-dependent numerical modeling of the collisionless reverse shock terminating the pulsar wind in the Crab Nebula. We treat the upstream relativistic wind as composed of ions and electronpositron plasma embedded in a toroidal magnetic field, flowing radially outward from the pulsar in a sector around the rotational equator. The relativistic cyclotron instability of th...
متن کاملNebula ’ S Wisps in Radio and Optical
We present four new, high-resolution VLA radio images of the Crab nebula, taken between 2001 February 25 and April 17. The radio images show systematic variability in the Crab's radio emission throughout the region near the pulsar. The principal geometry of the variable features is that of elliptical ripples very similar to the optical wisps. The radio wisps are seen to move systematically outw...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: International Astronomical Union Colloquium
سال: 2000
ISSN: 0252-9211
DOI: 10.1017/s0252921100060437