New Results from an old Friend: The Crab Nebula and its Pulsar

TL;DR

This paper summarizes recent Chandra X-ray observations of the Crab nebula and pulsar, revealing jet motion, positional offsets, spectral variations, and gamma-ray flare locations, providing new insights into this well-studied astrophysical object.

Contribution

It presents new observational findings on the Crab nebula's jet dynamics, pulsar position, spectral behavior, and gamma-ray flaring, using high-resolution X-ray data.

Findings

Long-term jet motion observed.

Pulsar offset from the projected ring.

Phase-resolved spectroscopy results.

Abstract

We summarize here the results, most of which are preliminary, of a number of recent observations of the Crab nebula system with the Chandra X-Ray Observatory. We discuss four different topics: (1) The motion on long (> 1yr) time scales of the southern jet. (2) The discovery that pulsar is not at the center of the projected ring on the sky and that the ring may well lie on the axis of symmetry but appears to be displaced at a latitude of about 5 degrees. (Note that this deprojection is by no means unique.) (3) The results and puzzling implications of the Chandra phase-resolved spectroscopy of the pulsar when compared to observations of pulse-phase variations of similar and dissimilar measures in other regions of the spectrum. (4) The search for the X-ray location of the site of the recently-discovered gamma-ray flaring. We also comment briefly on our plan to use the Chandra data we obtained for the previous project to study the nature of the low-energy flux variations recently detected at hard X-ray energies.