The Σ Problem of the Crab Pulsar Wind

نویسنده

  • F. Camilo
چکیده

The conversion of the Crab pulsar wind from one dominated by Poynting flux close to the star to one dominated by particle-born energy at the termination shock is considered. The idea put forward by Coroniti (1990) and criticised by Lyubarsky & Kirk (2001) that recon-nection in a striped wind is responsible, is generalised to include faster prescriptions for the a priori unknown dissipation rate. Strong acceleration of the wind is confirmed, and the higher dissipation rates imply complete conversion of Poynting flux into particle-born flux within the unshocked wind.

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Discovery of the Inner Ring around PSR B 1509 − 58

A Chandra study of pulsar wind nebula around the young energetic pulsar PSR B1509−58 is presented. The high resolution X-ray image with total exposure time of 190 ks reveals a ring like feature 10” apart from the pulsar. This feature is analogous to the inner ring seen in the Crab nebula and thus may correspond to a wind termination shock. The shock radius enables us to constrain the wind magne...

متن کامل

A wind model for high energy pulses

A solution to the σ problem — that of finding a mechanism capable of converting Poynting energy flux to particle-borne energy flux in a pulsar wind — was proposed several years ago by Coroniti and Michel who considered a particular prescription for magnetic reconnection in a striped wind. This prescription was later shown to be ineffective. In this paper, we discuss the basic microphysics of th...

متن کامل

Observational Constraints on Pulsar Wind Theories

Two-dimensional, relativistic, MHD simulations of pulsar-wind powered nebulae provide strong constraints on the properties of the winds themselves. In particular, they confirm that Poynting flux must be converted into particle energy close to or inside the termination shock front, emphasising the puzzle known as the σ paradox. To distinguish between the different possible resolutions of this pa...

متن کامل

Very high energy gamma radiation associated with the unshocked wind of the Crab pulsar

We show that the relativistic wind of the Crab pulsar, which is commonly thought to be invisible in the region upstream of the termination shock at r ≤ rS ∼ 0.1 pc, in fact could be directly observed through its inverse Compton (IC) γ-ray emission. This radiation is caused by illumination of the wind by low-frequency photons emitted by the pulsar, and consists of two, pulsed and unpulsed, compo...

متن کامل

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 کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2003