Open AccessLimits on the X‐ray emission from several hyperluminous IRAS galaxies
Author(s) -
Wilman R. J.,
Fabian A. C.,
Cutri R. M.,
Crawford C. S.,
Brandt W. N.
Publication year - 1998
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.1998.02047.x
Subject(s) - rosat , physics , astrophysics , galaxy , x ray , active galactic nucleus , astronomy , luminous infrared galaxy , optics
We report long, pointed ROSAT HRI observations of the hyperluminous galaxies IRAS F00235+1024, F12514+1027, F14481+4454 and F14537+1950. Two of them are optically classified as Seyfert‐like. No X‐ray sources are detected at the positions of any of the objects, with a mean upper limit L X / L Bol ≃ 2.3 × 10 −4 . This indicates that any active nuclei are either atypically weak at X‐ray wavelengths or obscured by column densities N H > 10 23 cm −2 . They differ markedly from ‘ordinary’ Seyfert 2 galaxies, bearing a closer resemblance in the soft X‐ray band to composite Seyfert 2 galaxies or to some types of starburst.