Chandra has performed a 1.4 Ms survey centred on the Hubble Deep Field-North (HDF-N), probing the X-ray Universe 55-550 times deeper than was possible with pre-Chandra missions. We describe the detected point and extended X-ray sources and discuss their overall multi-wavelength (optical, infrared, submillimetre and radio) properties. Special attention is paid to the HDF-N X-ray sources, luminou...

Chandra has performed a 1.4 Ms survey centred on the Hubble Deep Field-North (HDF-N), probing the X-ray Universe 55–550 times deeper than was possible with pre-Chandra missions. We describe the detected point and extended X-ray sources and discuss their overall multiwavelength (optical, infrared, submillimeter, and radio) properties. Special attention is paid to the HDF-N X-ray sources, luminou...

  Background: The sporadic cases of radiation-activated multiple sclerosis (MS) has been previously described, with a few studies focused on the relationship between radiation and the risk of MS. The aim of our study was to evaluate the association between history of X-ray radiation and MS.   Methods : This case-control study was conducted on 150 individuals including 65 MS patients and 85 age-...

introduction: clinical application of radiography in endodontic practice is affected by reproducibility in the orientation of the x-ray source, image receptor and object. the inability of dentists to locate intra oral films or sensors in appropriate positions in different cases can cause complications in the performance of endodontic therapy. commercially available film holder (endoray) and con...

background and objective: chest x-ray is usually the first radiography performed for a newborn. this test is easily accessible and yet a basic screening method. different results have been reported in various studies regarding the diagnostic value of chest x-ray in cardiovascular disease in children. materials and methods: the study was carried out retrospectively using the medical files of 100...

  Introduction: The Republic of Korea has developed a national standard based on which diagnostic X-ray equipment must be tested every 3 years. Accordingly, the performance of X-ray equipment used in all hospitals is evaluated by national certification bodies in compliance with the safety management regulations for X-ray equipment. However, if the equipment i...

We present results from a 479.7 ks Chandra exposure of the Hubble Deep Field North (HDF-N) and its immediate vicinity. In our X-ray image, the deepest ever reported with a 0.5–2.0 keV flux limit of ≈ 4.9 × 10 −17 erg cm −2 s −1 , we detect four new HDF-N X-ray sources bringing the total number of such sources to 12. The new sources include two optically bright (R = 18.3–18.8), low-redshift (z <...

We present results from a 479.7 ks Chandra exposure of the Hubble Deep Field North (HDF-N) and its immediate vicinity. In this X-ray image, the deepest ever reported with a 0.5–2.0 keV flux limit of ≈ 4.9 × 10 −17 erg cm −2 s −1 , four new HDF-N X-ray sources are detected bringing the total number of such sources to 12. The new sources include two optically bright (R = 18.3–18.8), low-redshift ...