NGC 2516 eROSITA X-ray observations

Furthermore, we extract X-ray spectra for all sources and fit two-component APEC models to them. To aid analysis, we group stars with similar mass and rotational properties, allowing us to investigate the influence of rotation on various X-ray properties. The colour-activity diagram of NGC 2516 shows a general increase of the fractional X-ray luminosity with spectral type change from F through G and K to M-type.

However, the behaviour of K-type stars, representing those best sampling the fast- to slow rotational transition, is more complex, with both increased and decreased X-ray emission relative to G-type stars for fast and slow rotators respectively. The rotation-activity diagram is analogous, with an identifiable desaturated group of X-ray emitters that corresponds to stars in the rotational gap between the fast and slow rotator sequences.

We prefer describing the normalized X-ray emission for all cluster stars as declining logarithmically with Rossby number over those using broken power laws. Coronal temperatures appear to be largely independent of mass or rotation. The coronal abundances are significantly sub-solar for most stars, as in prior work, but near-solar for both the least-active stars in our sample and a number of the very active stars.

The wealth of X-ray detections and rotation periods for stars in NGC 2516 enables a detailed view of the connection between rotation and X-ray activity in a homogeneous and coeval cluster sample of young stars.