Abstract

Poster - Splinter General   (Aula 1&2 / virtual plenum)

In-situ dust formation in M87 and the jet

Tom Richtler, Neil Nagar,Juan Osorno, Michael Hilker
Universidad de Concepcion, ESO

The occurence of dust in elliptical galaxies has been explained by infall events because of the lack of dust producers like AGB stars and supernovae. We present the prominent galaxy M87, the central galaxy of a Virgo subcluster, as an example for in-situ dust formation. Several dusty filaments emerge from M87 jet knots, as well as from the tip of the jet, and from the nucleus. Their thread-like morphology match well the [NII]-emission whose radial velocities are close to the systemic velocity. Rapid inflows or outflows are not identifiable. Striking is the low velocity dispersion of the gaseous emission, which suggests a confinement within magnetic fields. Dust formation must have been local in high-density pockets of warm/cold gas that has cooled down from the hot phase. The jet probes the interstellar medium, manifest by the detection of atomic [OI] emission in the brightest knots A and D. Relativistic bulk velocities are not supported. The reported superluminal velocities of jet knots should be understood as phase velocities that emerge from unresolved microstructure of the jet material. Our work use HST-ACS images and MUSE (wide-field and AO) cubes.