Context :

Aims : We revisit the X-ray properties of the main-sequence Hyades members and the relation between X-ray emission and stellar rotation .

Methods : As input catalog for Hyades members , we combined three recent Hyades membership lists derived from Gaia DR2 data including the Hyades core and its tidal tails .
We searched for X-ray detections from the ROSAT all-sky survey ( RASS ) and pointings from ROSAT , the Chandra X-Ray Observatory , and XMM-Newton of the main-sequence Hyades members .
Furthermore , we adopted rotation periods derived from Kepler ’ s K2 mission and other resources .

Results : We find an X-ray detection for 281 of 1066 bona fide main-sequence Hyades members and provide statistical upper limits for the undetected sources .
The majority of the X-ray detected stars is located in the Hyades core because of its generally smaller distance to the Sun .
F- and G-type stars have the highest detection fraction ( 72 % ) , while K- and M-type dwarfs have lower detection rates ( 22 % ) .
The X-ray luminosities of the detected members range from \sim 2 \times 10 ^ { 27 } erg s ^ { -1 } for late M-type dwarfs to \sim 2 \times 10 ^ { 30 } erg s ^ { -1 } for active binaries .
The X-ray luminosity distribution functions formally differ for the members in the core and tidal tails , which is likely caused by a larger fraction of field stars in our Hyades tails sample .
Compared to previous studies , our sample is slightly fainter in X-rays due to differences in the used Hyades membership list , furthermore , we extend the X-ray luminosity distribution to fainter luminosities .
The X-ray activity of F- and G-type stars is well defined at F _ { X } / F _ { \mathrm { bol } } \approx 10 ^ { -5 } .
The fractional X-ray luminosity and its spread increases to later spectral types reaching the saturation limit ( F _ { X } / F _ { \mathrm { bol } } \approx 10 ^ { -3 } ) for members later than spectral type M3 .
Confirming previous results , the X-ray flux varies by less than a factor of three between epochs for the 104 Hyades members with multiple epoch data , significantly less than expected from solar-like activity cycles .
Rotation periods are found for 204 Hyades members , with about half of them being detected in X-rays .
The activity-rotation-relation derived for the coeval Hyades members has properties very similar to those obtained by other authors investigating stars of different ages .

Conclusions :