Abstract


  ASSOCIATION OF CALCIUM NETWORK BRIGHT POINTS WITH UNDERNEATH PHOTOSPHERIC MAGNETIC PATCHES

  N. Narang, Indian Institute of Astrophysics, nancy@iiap.res.in
  D. Banerjee, Indian Institute of Astrophysics, dipu@iiap.res.in

Hinode has found concentrated kilogauss patches in the polar regions of Sun which are now shown to be correlated with facular bright points at the photospheric level. We expect the spatial intermittency of the magnetic field to persist even at the chromospheric level. Images taken in typical chromospheric and transition region lines show the presence of bright cells, usually known as network, while the surrounding dark regions is named internetwork. The small-scale brighter structures visible in the bright network lanes are termed as network bright points when observed in chromospheric and transition region lines. Polar network bright points are the ones which are present in the polar regions of the Sun (above 70$^{\circ}$ latitude). We used Ca~H images of chromosphere and photospheric line of sight (LOS) magentograms obtained by Solar Optical Telescope (SOT) along with HMI (Helioseismic Magnetic Imager) photospheric LOS magnetic data of Sun${^,}$s polar region in coronal holes for our analysis. We are able to find a considerable association between the polar network bright points and magnetic patches which led us to conclude that these bright points can serve as good proxy for polar magnetic fields. We have extended this study to equitorial coronal holes and quiet sun regions also. We observed that relative intensity of calcium network bright points is correlated well with LOS magnetic field in all the cases.