Cometary shaped sources at the Galactic Center - Evidence for a wind from the central 0.2 pc

Abstract

In 2007 we reported two cometary shaped sources in the vicinity of Sgr A* (0.8" and 3.4" projected distance), named X7 and X3. The symmetry axes of the two sources are aligned to within 5 degrees in the plane of the sky and the tips of their bow-shocks point towards Sgr A*. Our measurements show that the proper motion vectors of both features are pointing in directions more than 45 deg away from the line that connects them with Sgr A*. This misalignment of the bow-shock symmetry axes and their proper motion vectors, combined with the high proper motion velocities of several 100 km/s, suggest that the bow-shocks must be produced by an interaction with some external fast wind, possibly coming from Sgr A*, or stars in its vicinity. We have developed a bow-shock model to fit the observed morphology and constrain the source of the external wind. The result of our modeling allows us to estimate the velocity of the external wind, making sure that all likely stellar types of the bow-shock stars are considered. We show that neither of the two bow-shocks (one of which is clearly associated with a stellar source) can be produced by influence of a stellar wind of a single mass-losing star in the central parsec. Instead, an outflow carrying a momentum comparable to the one contributed by the ensemble of the massive young stars, can drive shock velocities capable of producing the observed cometary features. We argue that a collimated outflow arising perpendicular to the plane of the clockwise rotating stars (CWS), can easily account for the two features and the mini-cavity. However, the collective wind from the CWS has a scale of >10''. The presence of a strong, mass-loaded outbound wind at projected distances from Sgr A* of <1'' is in fact in agreement with models that predict a highly inefficient accretion onto the central black hole due to a strongly radius dependent accretion flow.

to appear in A&A

References in corpus (9)

• Monitoring stellar orbits around the Massive Black Hole in the Galactic Center
• Measuring Distance and Properties of the Milky Way's Central Supermassive Black Hole with Stellar Orbits
• The Two Young Star Disks in the Central Parsec of the Galaxy: Properties, Dynamics and Formation
• A Disk of Young Stars at the Galactic Center as Determined by Individual Stellar Orbits
• The structure of the nuclear stellar cluster of the Milky Way
• Dynamics of Ionized Gas at the Galactic Center: VLA Observations of the 3D Velocity Field and Location of the Ionized Streams in Sagittarius A West
• Interstellar Weather Vanes: GLIMPSE Mid-Infrared Stellar-Wind Bowshocks in M17 and RCW49
• First proper motions of thin dust filaments at the Galactic Center
• IRS 13N: a new comoving group of sources at the Galactic Center

Cited by in corpus (42)

• The Milky Way's Supermassive Black Hole: How good a case is it? A Challenge for Astrophysics & Philosophy of Science
• Wild at Heart:-The Particle Astrophysics of the Galactic Centre
• Near-infrared proper motions and spectroscopy of infrared excess sources at the Galactic Center
• Stellar transits across a magnetized accretion torus as a mechanism for plasmoid ejection
• New observations of the gas cloud G2 in the Galactic Center
• S62 and S4711: Indications of a population of faint fast moving stars inside the S2 orbit -- S4711 on a 7.6 year orbit around Sgr~A*
• The mean infrared emission of SagittariusA*
• Traces of past activity in the Galactic Centre
• Galactic Center Research: Manifestations of the Central Black Hole
• Evidence for A Parsec-scale Jet from The Galactic Center Black Hole: Interaction with Local Gas
• Monitoring the Dusty S-Cluster Object (DSO/G2) on its Orbit towards the Galactic Center Black Hole
• Polarized light from Sgr A* in the near-infrared $K_s$-band
• Dust-enshrouded star near supermassive black hole: predictions for high-eccentricity passages near low-luminosity galactic nuclei
• Monitoring dusty sources in the vicinity of Sgr A*
• Evidence for a jet and outflow from Sgr A*: a continuum and spectral line study
• Nature of the Galactic centre NIR-excess sources. I. What can we learn from the continuum observations of the DSO/G2 source?
• ALMA Detection of Bipolar Outflows: Evidence for Low Mass Star Formation within 1pc of Sgr A*
• Polarized near-infrared light of the Dusty S-cluster Object (DSO/G2) at the Galactic Center
• A Nonthermal Radio Filament Connected to the Galactic Black Hole?
• Depletion of bright red giants in the Galactic center during its active phases
• Properties of bow-shock sources at the Galactic center
• Near-infrared polarimetry as a tool for testing properties of accreting super-massive black holes
• Signatures of Young Star Formation Activity Within Two Parsecs of Sgr A*
• Effect of an isotropic outflow from the Galactic centre on the bow-shock evolution along the orbit
• Near- and mid-infrared observations in the inner tenth of a parsec of the Galactic center -- Detection of proper motion of a filament very close to Sgr~A*
• A new bow-shock source with bipolar morphology in the vicinity of Sgr A*
• ALMA and VLA observations of emission from the environment of Sgr A*
• Sgr A* and its Environment: Low Mass Star Formation, the Origin of X-ray Gas and Collimated Outflow
• ALMA Detection of Extreme Blue-Shifted Ionized Gas Within 0.2 pc of Sgr A* from -480 to -300 km/s
• First observed interaction of the circumstellar envelope of an S-star with the environment of Sgr A*
• The Swansong of the Galactic Center Source X7: An Extreme Example of Tidal Evolution near the Supermassive Black Hole
• Observation of the apoapsis of S62 in 2019 with NIRC2 and SINFONI
• X3: a high-mass Young Stellar Object close to the supermassive black hole Sgr~A*
• Mid-Infrared studies of dusty sources in the Galactic Center
• Signatures of an Encounter Between the G2 Cloud and a Jet from Sgr A*
• Electromagnetic signatures of strong-field gravity from accreting black holes
• Intrinsically Polarized Stars and Implication for Star Formation in the Central Parsec of Our Galaxy
• Red giant - jet collisions in galactic nuclei I: 3D hydrodynamical model of a few stellar orbits
• Ices in the Galactic Centre : solid ice and gaseous CO in the central parsec
• Galactic Center Minispiral: Interaction Modes of Neutron Stars
• The Galactic Center Black Hole Laboratory
• Closing the gap: Follow-up observations of peculiar dusty objects close to Sgr A* using ERIS