We present an optical to X-ray spectral analysis of four ‘ hypervariable ’ AGN ( HVAs ) discovered by comparing Pan-STARRS data to that from SDSS over a 10 year baseline ( Lawrence et al 2016 ) .
There is some evidence that these objects are X-ray loud for their corresponding UV luminosities , but given that we measured them in a historic high state , it is not clear whether to take the high-state or low-state as typical of the properties of these HVAs .
We estimate black hole masses based on Mg ii and H \alpha emission line profiles , and either the high and low state luminosities , finding mass ranges \log ( M _ { BH } / M _ { \odot } ) = 8.2 - 8.8 and \log ( M _ { BH } / M _ { \odot } ) = 7.9 - 8.3 respectively .
We then fit energy conserving models to the SEDs , obtaining strong constraints on the bolometric luminosity and \alpha _ { OX } .
We compare the SED properties with a larger , X-ray selected AGN sample for both of these scenarios , and observe distinct groupings in spectral shape versus luminosity parameter space .
In general , the SED properties are closer to normal if we assume that the low-state is representative .
This supports the idea that the large slow outbursts may be due to extrinsic effects ( for example microlensing ) as opposed to accretion rate changes , but a larger sample of HVAs is needed to be confident of this conclusion .