Galactic vs. Extragalactic Origin of the Peculiar Transient SCP 06F6

TL;DR

This paper evaluates multiple models for the peculiar transient SCP 06F6, favoring a tidal disruption by an intermediate-mass black hole, and ranks other scenarios including supernovae and asteroid impacts based on their plausibility.

Contribution

It provides a comparative analysis of various extragalactic and galactic models for SCP 06F6, proposing a preferred tidal disruption scenario involving a CO white dwarf and an IMBH.

Findings

The tidal disruption of a CO white dwarf by an IMBH is the most favored model.

A type Ia-like supernova inside a dense carbon star wind is a plausible alternative.

Galactic asteroid impact scenarios are less favored due to lack of predictive modeling.

Abstract

We study four scenarios for the SCP 06F6 transient event that was announced recently. Some of these were previously briefly discussed as plausible models for SCP 06F6, in particular with the claimed detection of a z=0.143 cosmological redshift of a Swan spectrum of a carbon rich envelope. We adopt this value of z for extragalactic scenarios. We cannot rule out any of these models, but can rank them from most to least preferred. Our favorite model is a tidal disruption of a CO white dwarf (WD) by an intermediate-mass black hole (IMBH). To account for the properties of the SCP 06F6 event, we have to assume the presence of a strong disk wind that was not included in previous numerical simulations. If the IMBH is the central BH of a galaxy, this explains the non detection of a bright galaxy in the direction of SCP 06F6. Our second favorite scenario is a type Ia-like SN that exploded inside the dense wind of a carbon star. The carbon star is the donor star of the exploded WD. Our third favorite model is a Galactic source of an asteroid that collided with a WD. Such a scenario was discussed in the past as the source of dusty disks around WDs, but no predictions exist regarding the appearance of such an event. Our least favorite model is of a core collapse SN. The only way we can account for the properties of SCP 06F6 with a core collapse SN is if we assume the occurrence of a rare type of binary interaction.