NGC 4565 Galaxy Is Found To Be Surrounded By Diffusive Radio Halo

Astronomers with the help of Low-Frequency Array (LOFAR) found a diffused radio halo circling the spiral galaxy NGC 4565. The finding can help shed some light on NGC 4565. The star-forming activity and the stretch of cosmic-ray electrons in this galaxy can be well-explained through the currently obtained data. The late-type spiral galaxies that are present in an edge-on orientation tend to show the presence of radio halos. The current study shows the radio halos to be mainly occupied by the non-thermal radio continuum element relative to the magnetic fields and cosmic ray electrons (CRe). The knowledge over the flight of cosmic rays in galaxies is hardly known. LOFAR seems to help make it possible by investigating the earlier CRe, which is far away from the star formation location present in the halos of galaxies.

According to Astronomer Volker Heesen and his team from the University of Hamburg, they used LOFAR to study the deep, low-frequency observations of NGC 4565 which is located 38.8 million light-years away. The quiescent spiral galaxy in the edge-on orientation shows an average mass surface density and low star-formation rate. The distribution of CRe and magnetic fields are being scrutinized by the astronomers. The astronomers while observing found the radio continuum of NGC 4565 to be warped just like a neutral hydrogen line warp. They also spotted some flaring of the radio halo from the galaxy.

The warp formed due to the vertical intensity profiles’ asymmetric nature is the reason behind the flare. The old population of CRe is seen to diffuse away slowly from the star-forming disc. Similarly by studying the outflow-to inflow-dominated rates, the researchers can very well explicate the reason for the difference in the behavior compared to NGC 7462. NGC 7462 is the only galaxy that has revealed the presence of a diffuse radio halo. Thus, through these observations, it can be made clear that LOFAR can help enlighten on cosmic rays and galaxy evolution.