Wolf-Rayets in Gaia

Benjamin Pope, NYU

Gaia DR2

Collaborators Peter Tuthill, Peredur Williams, Paul Crowther, Joe Callingham.
Slides available at
benjaminpope.github.io/talks/gaiadr2/gaiadr2

Wolf-Rayets

Wolf-Rayets are the last stage in the life cycles of the most massive stars (~>25 Msun)

Thought to be progenitors of Type 1bc supernovae and long gamma-ray bursts

Colliding Wind Binaries

WR colliding wind binaries (eg WR+OI) produce dust in a 'pinwheel' spiral, like WR 104. Spiral evolution encodes binary parameters.

Crossmatched Gaia DR2 with Crowther WR catalog.

Gaia Optical color-magnitude diagram

Gaia NIR color-magnitude diagram

Not a reddening sequence?

Why is the astrometry so bad? Binarity?

REX 1

Joe Callingham (ASTRON) found a very strange colliding wind binary (CWB) in 2012 cross-matching Molonglo 843 MHz, 2XMM (X-ray) and WISE (IR) catalogs.

2MASS, DSS, XMM

We thought it could be a colliding wind binary producing dust in a 'pinwheel' spiral.
So we got VLT/NACO (inset) and VISIR (main) images...
Whoah! Never seen a pinwheel this complex before. Wanted second epoch to make a video like before.
We did get a second epoch... and it expanded 1.1 pixels.
From conjectured membership of Majaess 170 cluster, expected distance of 1.8 +- 0.2 kpc.

Expected 10 pix expansion from wind spectra P Cygni profile (3400 km/s)!

Gaia DR2 gives us 0.58 +- 0.11 kpc.

... and Majaess 170 isn't even a cluster!