Detection of polarized continuum emission of the Dusty S-cluster Object (DSO/G2)

Abstract

A peculiar source in the Galactic center known as the Dusty S-cluster Object (DSO/G2) moves on a highly eccentric orbit around the supermassive black hole with the pericenter passage in the spring of 2014. Its nature has been uncertain mainly because of the lack of any information about its intrinsic geometry. For the first time, we use near-infrared polarimetric imaging data to obtain constraints about the geometrical properties of the DSO. We find out that DSO is an intrinsically polarized source, based on the significance analysis of polarization parameters, with the degree of the polarization of $\sim 30\%$ and an alternating polarization angle as it approaches the position of Sgr A*. Since the DSO exhibits a near-infrared excess of $K_{\mathrm{s}}-L^{\prime }>3$ and remains rather compact in emission-line maps, its main characteristics may be explained with the model of a pre-main-sequence star embedded in a non-spherical dusty envelope.

arXiv comment2 pages, 1 figure, IAU Symposium 322, The Multi-Messenger Astrophysics of the Galactic Centre, Steve Longmore, Geoff Bicknell and Roland Crocker, eds

References in corpus (5)

• A gas cloud on its way towards the super-massive black hole in the Galactic Centre
• Detection of Galactic Center source G2 at 3.8 $\mu$m during periapse passage
• The Galactic Center cloud G2 and its gas streamer
• Monitoring the Dusty S-Cluster Object (DSO/G2) on its Orbit towards the Galactic Center Black Hole
• Effect of an isotropic outflow from the Galactic centre on the bow-shock evolution along the orbit

Cited by in corpus (1)

• First observed interaction of the circumstellar envelope of an S-star with the environment of Sgr A*