Discovery of the narrow-line Seyfert 1 galaxy Markarian 335 in a historical low X-ray flux state

Dirk Grupe, Stefanie Komossa, Luigi C. Gallo

Research output: Contribution to journalArticlepeer-review

55 Citations (Scopus)

Abstract

We report the discovery of the narrow- line Seyfert 1 galaxy Mrk 335 in an extremely low X- ray state. A comparison of Swift observations obtained in 2007 May and June/ July with all previous X- ray observations between 1971 and 2006 show the AGN to have diminished in flux by a factor of more than 30, the lowest X- ray flux Mrk 335 has ever been observed in. The Swift observations show an extremely hard X- ray spectrum at energies above 2 keV. Possible interpretations include partial- covering absorption or X- ray reflection from the disk. In this Letter we consider the partial- covering interpretation. The Swift observations can be well fit by a strong partial- covering absorber with varying absorption column density [N-H=(1-4)x10(23) cm(-2)] and a covering fraction. f(c)=0.9-1. When corrected for intrinsic absorption, the X-ray flux of Mrk 335 varies by only factors of 4 - 6. In the UV Mrk 335 shows variability on the order of 0.2 mag. We discuss the similarity of Mrk 335 to the highly variable NLS1 WPVS 007, and speculate about a possible link between NLS1 galaxies and broad- absorption- line quasars.

Original languageEnglish
Number of pages4
JournalAstrophysical Journal Letters
Volume668
Publication statusPublished - 20 Oct 2007

Keywords

  • galaxies : active
  • galaxies : individual (Markarian 335)
  • galaxies : Seyfert
  • ultraviolet : galaxies
  • X-rays : galaxies
  • ACTIVE GALACTIC NUCLEI
  • XMM-NEWTON OBSERVATIONS
  • QUASI-STELLAR OBJECTS
  • COMPLETE SAMPLE
  • GINGA OBSERVATIONS
  • LOW-REDSHIFT
  • RADIO-LOUD
  • VARIABILITY
  • ABSORPTION
  • MRK-335

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