XMM-Newton-NEWS

CONTENTS

• XMM-Newton Users' Group Meeting #23: Invitation from the UG Chair
• EPIC effective area update
• Announcement of opportunity for XRISM Guest Scientists

XMM-Newton Users' Group Meeting #23: Invitation from the UG Chair

The XMM-Newton Users' Group will be holding its yearly meeting this coming May 16th and 17th.

As is usual, the UG welcomes all comments and suggestions on any relevant aspect of XMM-Newton operations and future direction.

You may send these either directly to me, or if you prefer to any member of the UG, before May 6th.

Rudy Wijnands, UG-Chair

The agenda for UG Meeting #23 and contact information of the UG chair and all the other UG members are available at

http://www.cosmos.esa.int/web/xmm-newton/users-group/

EPIC effective area update

An update to the EPIC effective area is now available, which improves the agreement of spectral shapes between XMM-Newton EPIC and NuSTAR. Based on NuSTAR's stray-light observations of the Crab and corresponding calibration update of NuSTAR, the XMM-Newton EPIC effective area is changed by up to 8% above 3 keV. This update removes significant residuals in the 3-12 keV range between simultaneous fits of NuSTAR and XMM-Newton EPIC data.

This change can be activated in SAS version 20.0 (released in November 2021) or later, setting the arfgen keyword "applyabsfluxcorr=yes", and is published in CCF XRT3_XAREAEF_0014.CCF. This option is not activated by default to allow scientists to test them on a large variety of sources and provide feedback to the SOC. The update does not correct for energy-independent absolute scaling of one instrument to the other, hence it is advised to allow the spectral normalisations between the instruments to be adjustable.

This update is based on the EPIC-pn data, but can also be applied to EPIC-MOS. The agreement between MOS and pn can be further improved by setting "applyxcaladjustment=yes" in arfgen.

More details on the correction procedure and changes can be found in the associated CCF Release Note, as well as in the accompanying Technical Note.

We encourage all scientists using XMM-Newton to apply and test these changes and provide feedback to the XMM-Newton SOC via the Helpdesk. Feedback may include whether fit residuals got smaller and the values of the different normalisation factors per instrument.

Announcement of opportunity for XRISM Guest Scientists

ESA solicits the participation of the scientific community of ESA Member States in the role of Guest Scientists for the XRISM mission. Through the appointment of the XRISM Guest Scientists (XGS), ESA aims at involving a scientific community as wide and diverse as possible in the exploitation of the data of the Performance Verification Phase of the XRISM mission.

XGSs are expected to enhance the scientific return of the XRISM Performance Verification observations by bringing unique expertise that includes, but is not limited to: complementary data on the target from other X-ray observatories or other wavebands, substantial theoretical insight, or specialized data analysis techniques.

Detailed information can be found at

https://www.cosmos.esa.int/web/xrism-xgs-2022/

Yours sincerely,

XMM-Newton SOC