Abstract
BURBIDGE1, classified extragalactic objects with bright nuclei into three classes: in order of increasing optical luminosity these are (1) Seyfert galaxies; (2) N galaxies; (3) quasars. Many Seyferts and several quasars have been shown to be X-ray sources. Here we show that N galaxies are also powerful X-ray sources. In fact, all six N galaxies in the 3C radio catalogue with redshifts less than 0.06 (ref. 2) are detected by the first full-sky survey of the Goddard Space Flight Center detectors (A2) on HEAO 1. X-ray emission has also been discovered from a strong Southern Hemisphere radio source, the N galaxy Pic A. Six of the seven objects are classified as broad-line radio galaxies (BLRGs)3–5 and one (3C371) is classified as a BL Lac object6. These objects are differentiated from the newly discovered class of ‘emission line’ galaxies7 by their high radio flux and extremely broad lines. Before HEAO 1 there was one confirmed N galaxy, 3C120 (ref. 8), and one suggested, 3C390.3 (refs 9, 10). We detect 3C120, strengthen the identification of 3C390.3, and present evidence for X-ray emission from four new sources, 3C111, 3C382, 3C371, and Pic A. We also suggest 3C445 as the identification of 2A2220-022 (ref. 11).
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References
Burbidge, G. A. Rev. Astr. Astrophy. 8, 369 (1978).
Smith, H. E., Spinrad, H. & Smith, E. O. P.A.S.P. 88, 64 (1976).
Grandi, S. & Osterbrock, D. E. Astrophys. J. 220, 783 (1978).
Sargent, W. Astrophys. J. Lett. 212, L105 (1977).
Danzieger, I. J., Fosbury, R. A. E. & Penston, M. V. Mon. Not. R. astr. Soc. 179, 41 (1977).
Miller, J. BL Lac Conf. Proc. (ed. Wolfe, A.) (1978).
Schnopper, H. W., Davis, M., Delvaille, J. P., Geller, M. J. & Hunchra, J. P. Nature (submitted).
Schnopper, H. W. et al. Astrophys. J. Lett. 215, 7 (1977).
Charles, P. A., Longair, M. S. & Sanford, P. W. Mon. Not. R. astr. Soc. 170, 17 (1978).
Forman, W. et al. Astrophys. J. Suppl. (submitted).
Cooke, B. A. et al. Mon. Not. R. astr. Soc. 182, 489 (1978).
Jones, T. W., O'Dell, S. L. & Stein, W. A. Astrophys. J. 188, 353 (1974).
Mushotzky, R. F., Baity, W. A. & Peterson, L. E. Astrophys. J. 212, 22 (1977).
Elvis, M. et al. Mon. Not. R. astr. Soc. 183, 129 (1978).
Fabian, A. preprint.
Mushotzky, R. F., Serlemitsos, P. J., Becker, R. H., Boldt, E. A. & Holt, S. S. Astrophys. J. 220, 790 (1978).
Marshall, F. E. et al. Bull. Am. astr. Soc. 10, 433 (1978).
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MARSHALL, F., MUSHOTZKY, R., BOLDT, E. et al. N Galaxies—a new class of X-ray sources. Nature 275, 624–625 (1978). https://doi.org/10.1038/275624a0
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DOI: https://doi.org/10.1038/275624a0
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