Context :

Aims : To study the dynamical evolution of trans-equatorial loops ( TELs ) using imaging and spectroscopy .

Methods : We have used the images recorded by the Atmospheric Imaging Assembly and the Helioseismic Magnetic Imager on-board the Solar Dynamics Observatory and spectroscopic observations taken from the Extreme-Ultraviolet Imaging Spectrometer on-board Hinode .

Results : The data from AIA 193 Å channel show that TELs are formed between AR 12230 and a newly emerging AR 12234 and evolved during December 10–14 , 2014 .
The xt-plots for December 12 , 2014 obtained using AIA 193 Å data reveal signatures of inflow and outflow towards an X-region .
High cadence AIA images also show recurrent intensity enhancements in close proximity to the X-region ( P2 ) , which is observed to have higher intensities for spectral lines formed at \log T [ K ] = 6.20 and voids at other higher temperatures .
The electron densities and temperatures in the X-region ( and P2 ) are maintained steadily at \log N _ { e } = 8.5–8.7 cm ^ { -3 } and \log T [ K ] = 6.20 , respectively .
Doppler velocities in the X-region show predominant redshifts by about 5–8 km s ^ { -1 } when closer to the disk centre but blueshifts ( along with some zero-velocity pixels ) when away from the centre .
The Full-Width-Half-Maxima ( FWHM ) maps reveal non-thermal velocities of about 27–30 km s ^ { -1 } for Fe xii , Fe xiii and Fe xv lines .
However , the brightest pixels have non- thermal velocities \sim 62 km s ^ { -1 } for Fe xii and Fe xiii lines .
On the contrary , the dark X-region for Fe xv line have the highest non-thermal velocity ( \sim 115 km s ^ { -1 } ) .

Conclusions : We conclude that the TELs are formed due to magnetic reconnection .
We further note that the TELs themselves undergo magnetic reconnection leading to reformation of loops of individual ARs .
Moreover , this study , for the first time , provides measurements of plasma parameters in X-regions thereby providing essential constraints for theoretical studies .