We present XMM-Newton observations of a trail of enhanced X-ray emission extending along the full 8 ′ .7×4 ′ region between the large spiral galaxy NGC 6872 and the dominant elliptical galaxy NGC 6876 in the Pavo Group, the first known X-ray trail associated with a spiral galaxy in a poor galaxy group and, with projected length of 90 kpc, one of the longest X-ray trails observed in any system. The X-ray surface brightness in the trail region is roughly constant beyond ∼ 20 kpc of NGC 6876 in the direction of the spiral. The trail is hotter (∼ 1 keV) than the undisturbed Pavo IGM (∼ 0.5 keV) and has low metal abundances (0.2 Z ⊙ ). The 0.5 − 2 keV luminosity of the trail, measured using a 67 × 90 kpc rectangular region, is 6.6 × 10 40 erg s −1 . We compare the properties of gas in the trail to the spectral properties of gas in the spiral NGC 6872 and in the elliptical NGC 6876 to constrain its origin. We suggest that the X-ray trail is either IGM gas gravitationally focused into a Bondi-Hoyle wake, a thermal mixture of ∼ 64% Pavo IGM gas with ∼ 36% galaxy gas that has been removed from the spiral NGC 6872 by turbulent viscous stripping, or both, due to the spiral's supersonic motion at angle ξ ∼ 40 • with respect to the plane of the sky, past the Pavo group center (NGC 6876) through the densest region of the Pavo IGM. Assuming ξ = 40 • and a filling factor η in a cylindrical volume with radius 33 kpc and projected length 90 kpc, the mean electron density and total hot gas mass in the trail is 9.5 × 10 −4 η −1/2 cm −3 and 1.1 × 10 10 η 1/2 M ⊙ , respectively.

The Policy Research Working Paper Series disseminates the findings of work in progress to encourage the exchange of ideas about development issues. An objective of the series is to get the findings out quickly, even if the presentations are less than fully polished. The papers carry the names of the authors and should be cited accordingly. The findings, interpretations, and conclusions expressed in this paper are entirely those of the authors. They do not necessarily represent the views of the International Bank for Reconstruction and Development/World Bank and its affiliated organizations, or those of the Executive Directors of the World Bank or the governments they represent.

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The Policy Research Working Paper Series disseminates the findings of work in progress to encourage the exchange of ideas about development issues. An objective of the series is to get the findings out quickly, even if the presentations are less than fully polished. The papers carry the names of the authors and should be cited accordingly. The findings, interpretations, and conclusions expressed in this paper are entirely those of the authors. They do not necessarily represent the views of the International Bank for Reconstruction and Development/World Bank and its affiliated organizations, or those of the Executive Directors of the World Bank or the governments they represent.

T his paper provides an ex-ante assessment of the expected economic impact of the post-2020 EU Research and Innovation Framework Programme, Horizon Europe. A key novelty in the approach is the use of three different macroeconomic models for the assessment of the continuation of the current Programme, Horizon 2020: NEMESIS, QUEST and RHOMOLO. In addition, NEMESIS is used to assess different batches of policy options related to the budget, management and design of Horizon Europe. The paper also highlights key aspects and assumptions that policy-makers and researchers need to consider for this type of analysis such as budget allocation, performance, leverage and financing modes.