Launched on 2021 December 9, the Imaging X-ray Polarimetry Explorer (IXPE) is a NASA Small Explorer Mission in collaboration with the Italian Space Agency (ASI). The mission will open a new window of investigation—imaging x-ray polarimetry. The observatory features three identical telescopes, each consisting of a mirror module assembly with a polarization-sensitive imaging x-ray detector at the focus. A coilable boom, deployed on orbit, provides the necessary 4-m focal length. The observatory utilizes a three-axis-stabilized spacecraft, which provides services such as power, attitude determination and control, commanding, and telemetry to the ground. During its 2-year baseline mission, IXPE will conduct precise polarimetry for samples of multiple categories of x-ray sources, with follow-on observations of selected targets.
Scheduled to launch in late 2021 the Imaging X-ray Polarimetry Explorer (IXPE) is a Small Explorer Mission designed to open up a new window of investigation -- X-ray polarimetry. The IXPE observatory features 3 identical telescope each consisting of a mirror module assembly with a polarization-sensitive imaging x-ray detector at its focus. An extending beam, deployed on orbit provides the necessary 4 m focal length. The payload sits atop a 3-axis stabilized spacecraft which among other things provides power, attitude determination and control, commanding, and telemetry to the ground. During its 2-year baseline mission, IXPE will conduct precise polarimetry for samples of multiple categories of x-ray sources, with follow-on observations of selected targets. IXPE is a partnership between NASA and the Italian Space Agency (ASI).
IXPE (Imaging X-ray Polarimetry Explorer) is the next Nasa Small Explorer mission foreseen for the lunch in 2021. It is a partnership with the Italian Space Agency (ASI). IXPE is devoted to X-ray polarimetry in the 2-8 keV energy band. The IXPE telescope comprises three grazing incidence mirror modules coupled to three detector units hosting each one a Gas Pixel Detector (GPD) polarimeter. The GPD exploits the photoelectric effect to measure the linear polarization of the X-ray emission from astrophysical sources. A wide and accurate on ground calibration was carried out on the IXPE detector units at INAF-IAPS in Italy. A dedicated facility was set-up to calibrate the detector units with polarized and unpolarised X-rays at different energies before Instrument integration.
IXPE (Imaging X-ray Polarimetry Explorer) is a NASA SMEX in a partnership with ASI. The focal plane Detector Units (DUs) and the Detector Service Unit (DSU) were developed by the Italian research Institutes INAF-IAPS and INFN and were manufactured by OHB-I. IXPE will investigate X-ray polarimetry in the 2-8 keV energy band. The payload comprises three identical telescopes, each composed of a mirror and a detector unit with an X-ray polarimeter based on the Gas Pixel Detector (GPD). A stray-light collimator (SLC) is mounted on the top of the DU to shield the GPD from background X-rays not coming from the optics. At the bottom of the SLC, an ions-UV filter is mounted to reduce the thermal load and to prevent ions and UV from entering the DU. The ions-UV filters consist mainly of 1 um LUXFilm (based on polyimide). During on-ground calibration activities of the IXPE DUs, X-ray transparency of DU-FM ions-UV filters was measured with monochromatic X-ray at 2.7 keV and 6.4 keV at INAF-IAPS.
IXPE, the Imaging X-ray Polarimetry Explorer, is a NASA SMEX mission with an important contribution of ASI that will be launched with a Falcon 9 in 2021 and will reopen the window of X-ray polarimetry after more than 40 years. The payload features three identical telescopes each one hosting one light-weight X-ray mirror fabricated by MSFC and one detector unit with its in-orbit calibration system and the Gas Pixel Detector sensitive to imaging X-ray polarization fabricated by INAF/IAPS, INFN and OHB Italy. The focal length after boom deployment from ATK-Orbital is 4 m, while the spacecraft is being fabricated by Ball Aerospace. The sensitivity will be better than 5.5% in 300 ks for a 1E-11 erg/s/cm2 (half mCrab) in the energy band of 2-8 keV allowing for sensitive polarimetry of extended and point-like X-ray sources. The focal plane instrument is completed, calibrated and it is going to be delivered at MSFC. We will present the status of the mission at about one year from the launch.
The NASA/ASI imaging x-ray polarimetry explorer, which will be launched in 2021, will be the first instrument to perform spatially resolved x-ray polarimetry on several astronomical sources in the 2- to 8-keV energy band. These measurements are made possible owing to the use of a gas pixel detector (GPD) at the focus of three x-ray telescopes. The GPD allows simultaneous measurements of the interaction point, energy, arrival time, and polarization angle of detected x-ray photons. The increase in sensitivity, achieved 40 years ago, for imaging and spectroscopy with the Einstein satellite will thus be extended to x-ray polarimetry for the first time. The characteristics of gas multiplication detectors are subject to changes over time. Because the GPD is a novel instrument, it is particularly important to verify its performance and stability during its mission lifetime. For this purpose, the spacecraft hosts a filter and calibration set (FCS), which includes both polarized and unpolarized calibration sources for performing in-flight calibration of the instruments. We present the design of the flight models of the FCS and the first measurements obtained using silicon drift detectors and charge-coupled device cameras, as well as those obtained in thermal vacuum with the flight units of the GPD. We show that the calibration sources successfully assess and verify the functionality of the GPD and validate its scientific results in orbit; this improves our knowledge of the behavior of these detectors in x-ray polarimetry.
The Imaging X-ray Polarimetry Explorer (IXPE) will add polarization to the properties (time, energy, and position) observed in x-ray astronomy. A NASA Astrophysics Small Explorer (SMEX) in partnership with the Italian Space Agency (ASI), IXPE will measure the 2–8-keV polarization of a few dozen sources during the first 2 years following its 2021 launch. The IXPE Observatory includes three identical x-ray telescopes, each comprising a 4-m-focal-length (grazingincidence) mirror module assembly (MMA) and a polarization-sensitive (imaging) detector unit (DU), separated by a deployable optical bench. The Observatory’s Spacecraft provides typical subsystems (mechanical, structural, thermal, power, electrical, telecommunications, etc.), an attitude determination and control subsystem for 3-axis stabilized pointing, and a command and data handling subsystem communicating with the science instrument and the Spacecraft subsystems.
The Imaging X-ray Polarimetry Explorer (IXPE) will expand the information space for study of cosmic sources, by adding polarization to the properties (time, energy, and position) observed in x-ray astronomy. Selected in 2017 January as a NASA Astrophysics Small Explorer (SMEX) mission, IXPE will be launched into an equatorial orbit in 2021. The IXPE observatory includes three identical x-ray telescopes, each comprising a 4-m-focal-length (grazing-incidence) mirror module assembly (MMA) and a polarization-sensitive (imaging) detector unit (DU). The optical bench separating the MMAs from the DUs is a deployable boom with a tip/tilt/rotation stage for DU-to-MMA (gang) alignment, similar to the configuration used for the NuSTAR observatory. The IXPE mission will provide scientifically meaningful measurements of the x-ray polarization of a few dozen sources in the 2-8 keV band, over the first two years of the mission. For several bright, extended x-ray sources (pulsar wind nebulae, supernova remnants, and an active-galaxy jet), IXPE observations will produce polarization maps indicating the magnetic structure of the synchrotron emitting regions. For many bright pulsating x-ray sources (isolated pulsars, accreting x-ray pulsars, and magnetars), IXPE observations will produce phase-resolved profiles of the polarization degree and position angle.
IXPE scientific payload comprises of three telescopes, each composed of a mirror and a photoelectric polarimeter based on the Gas Pixel Detector design. The three focal plane detectors, together with the unit which interfaces them to the spacecraft, are named IXPE Instrument and they will be built and calibrated in Italy; in this proceeding, we will present how IXPE Instrument will be calibrated, both on-ground and in-flight. The Instrument Calibration Equipment is being finalized at INAF-IAPS in Rome (Italy) to produce both polarized and unpolarized radiation, with a precise knowledge of direction, position, energy and polarization state of the incident beam. In flight, a set of four calibration sources based on radioactive material and mounted on a filter and calibration wheel will allow for the periodic calibration of all of the three IXPE focal plane detectors independently. A highly polarized source and an unpolarized one will be used to monitor the response to polarization; the remaining two will be used to calibrate the gain through the entire lifetime of the mission.
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