The mass and spin of the extreme Narrow Line Seyfert 1 Galaxy 1H 0707-495 and its implications for the trigger for relativistic jets

Abstract

Relativistic reflection models of the X-ray spectrum of the ‘complex’ Narrow Line Seyfert 1 (NLS1) 1H 0707−495 require a high-spin, moderate-inclination, low-mass black hole. With these parameters fixed, the observed optical/UV emission directly determines the mass accretion rate through the outer disc and hence predicts the bolometric luminosity. This is 140–260 times the Eddington limit. Such a disc should power a strong wind, and winds are generically expected to be clumpy. Changing inclination angle with respect to a clumpy wind structure gives a possible explanation for the otherwise puzzling difference between ‘complex’ NLS1 such as 1H 0707−495 and ‘simple’ ones like PG 1244+026. Lines of sight which intercept the wind show deep absorption features at iron from the hot phase of the wind, together with stochastic dips and complex absorption when the clumps occult the X-ray source (complex NLS1), whereas both these features are absent for more face-on inclination (simple NLS1). This geometry is quite different from the clean view of a flat disc which is assumed for the spin measurements in relativistic reflection models, so it is possible that even 1H 0707−495 has low spin. If so, this re-opens the simplest and hence very attractive possibility that high black hole spin is a necessary and sufficient condition to trigger highly relativistic (bulk Lorentz factor ∼10–15) jets.