IXPE

The IXPE mission was announced on 3 January 2017 The principal investigator is Martin C. Weisskopf of NASA Marshall Space Flight Center; he is the chief scientist for X-ray astronomy at NASA's Marshall Space Flight Center and project scientist for the Chandra X-ray Observatory spacecraft. Other partners include the McGill University, Massachusetts Institute of Technology (MIT), Roma Tre University, Stanford University, and the University of Colorado Boulder. == Objectives ==

The technical and science objectives include: • Improve polarization sensitivity by two orders of magnitude over the X-ray polarimeter aboard the Orbiting Solar Observatory 8 • Provide simultaneous spectral, spatial, and temporal measurements • Determine the geometry and the emission mechanism of active galactic nuclei and microquasars • Find the magnetic field configuration in magnetars and determine the magnitude of the field • Find the mechanism for X-ray production in pulsars (both isolated and accreting) and the geometry • Determine how particles are accelerated in pulsar wind nebula == Telescopes ==

The space observatory features three identical telescopes designed to measure the polarization of cosmic X-rays. Principle IXPE's payload is a set of three identical imaging X-ray polarimetry systems mounted on a common optical bench and co-aligned with the pointing axis of the spacecraft. a type of Micropattern gaseous detector, rely on the anisotropy of the emission direction of photoelectrons produced by polarized photons to gauge with high sensitivity the polarization state of X-rays interacting in a gaseous medium. Position-dependent and energy-dependent polarization maps of such synchrotron-emitting sources will reveal the magnetic-field structure of the X-ray emitting regions. X-ray polarimetric imaging better indicates the magnetic structure in regions of strong electron acceleration. The system is capable to resolve point sources from surrounding nebular emission or from adjacent point sources. == Launch profile ==

IXPE was launched on 9 December 2021 on a SpaceX Falcon 9 (B1061.5) from LC-39A at NASA's Kennedy Space Center in Florida. The relatively small size and mass of the observatory falls well short of the normal capacity of SpaceX's Falcon 9 launch vehicle. However, Falcon 9 had to work to get IXPE into the correct orbit because IXPE is designed to operate in an almost exactly equatorial orbit with a 0° inclination. Launching from Cape Canaveral, which is located 28.5° above the equator, it was physically impossible to launch directly into a 0.2° equatorial orbit. Instead, the rocket needed to launch due east into a parking orbit and then perform a plane, or inclination, change once in space, as the spacecraft crossed the equator. For Falcon 9, this meant that even the tiny IXPE likely still represented about 20–30% of its maximum theoretical performance () for such a mission profile, while the same launch vehicle is otherwise able to launch about to the same orbit IXPE was targeting when no plane change is needed, while recovering the first stage booster. IXPE is the first satellite dedicated to measuring the polarization of X-rays from a variety of cosmic sources, such as black holes and neutron stars. The orbit hugging the equator will minimize the X-ray instrument's exposure to radiation in the South Atlantic Anomaly, the region where the inner Van Allen radiation belt comes closest to Earth's surface. == Operations ==

IXPE is built to last for two years. 30 targets are planned to be observed during IXPE's first year. == Results ==

In May 2022 the first study of IXPE hinted the possibility of vacuum birefringence on 4U 0142+61 and in August another study looked at Centaurus A measuring low polarization degree, suggesting that the X-ray emission is coming from a scattering process rather than arising directly from the accelerated particles of the jet. In October 2022 it observed the gamma ray burst GRB 221009A, also known as the "Brightest of all time" (BOAT). == Gallery ==

File:IXPE-space-telescope-drawing.png|Diagram of IXPE's structure File:Images from IXPE Prelaunch press conference 03.jpg|IXPE before launch File:IXPE deploying.webm|Animation of the IXPE deployment process File:This image from NASA’s Imaging X-ray Polarimetry Explorer maps the intensity of X-rays coming from the observatory’s first target, the supernova Cassiopeia A.png|IXPE X-ray image of the supernova remnant Cassiopeia A == See also ==