AGN Type-casting: Mrk 590 No Longer Fits the Role

Understand

We present multi-wavelength observations that trace more than 40 years in the life of the active galactic nucleus (AGN) in Mrk 590, traditionally known as a classic Seyfert 1 galaxy.

• From spectra recently obtained from HST, Chandra, and the Large Binocular Telescope, we find that the activity in the nucleus of Mrk 590 has diminished so significantly that the continuum luminosity is a factor of 100 lower than the peak luminosity probed by our long baseline observations.
• Furthermore, the broad emission lines, once prominent in the UV/optical spectrum, have all but disappeared.
• Since AGN type is defined by the presence of broad emission lines in the optical spectrum, our observations demonstrate that Mrk 590 has now become a "changing look" AGN.