Sgr A* and its Environment: Low Mass Star Formation, the Origin of X-ray Gas and Collimated Outflow

Abstract

We present high-resolution multiwavelength radio continuum images of the region within 150$"$ of Sgr A*, revealing a number of new extended features and stellar sources in this region. First, we detect a continuous 2" east-west ridge of radio emission, linking Sgr A* and a cluster of stars associated with IRS 13N and IRS 13E. The ridge suggests that an outflow of east-west blob-like structures is emerging from Sgr A*. We also find arc-like features within the ridge with morphologies suggestive of photoevaporative protoplanetary disks. We use near-IR fluxes to show that the emission has similar characteristics to those of a protoplanetary disk irradiated by the intense radiation field at the Galactic center. This suggests that star formation has taken place within the S cluster 2$"$ from Sgr A*. We suggest that the diffuse X-ray emission associated with Sgr A* is due to an expanding hot wind produced by the mass loss from B-type main sequence stars, and/or the disks of photoevaporation of low mass YSOs at a rate ~10^{-6} solar mass per year. The proposed model naturally reduces the inferred accretion rate and is an alternative to the inflow-outflow style models to explain the underluminous nature of Sgr A*. Second, we detect new cometary radio and nea-IR sources and a striking tower of radio emission suggesting that they are tracing interaction sites of a mildly relativistic jet from Sgr A* with the atmosphere of stars and the nonthermal Sgr A East shell at a PA$\sim 50-60^{\circ }$ with ~10^{-7} solar mass per year, and opening angle 10 degrees.

45 pages, 12 figures, ApJ (in press)

References in corpus (25)

• Mass loss from hot massive stars
• An Unambiguous Detection of Faraday Rotation in Sagittarius A*
• Flaring Activity of Sgr A* at 43 and 22 GHz: Evidence for Expanding Hot Plasma
• Galactic Centre stellar winds and Sgr A* accretion
• Soft X-ray Temperature Tidal Disruption Events from Stars on Deep Plunging Orbits
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• Simultaneous NIR/sub-mm observation of flare emission from SgrA*
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• First proper motions of thin dust filaments at the Galactic Center
• ALMA and VLA measurements of frequency-dependent time lags in Sagittarius A*: evidence for a relativistic outflow
• A Catalog of Diffuse X-ray-Emitting Features within 20 pc of Sgr A*: Twenty Pulsar Wind Nebulae?
• The Intrinsic Two-Dimensional Size of Sagittarius A*
• Polarized light from Sgr A* in the near-infrared $K_s$-band
• Impact of Winds from Intermediate-Mass Stars on Molecular Cloud Structure and Turbulence
• Compact Radio Sources within 30" of Sgr A*: Proper Motions, Stellar Winds and the Accretion Rate onto Sgr A*
• Properties of bow-shock sources at the Galactic center
• Compact mid-IR sources east of galactic center source IRS5
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Cited by in corpus (14)

• A population of dust-enshrouded objects orbiting the Galactic black hole
• Chandra Spectral and Timing Analysis of Sgr A*'s Brightest X-ray Flares
• WISDOM Project -- IX Giant Molecular Clouds in the Lenticular Galaxy NGC4429: Effects of Shear and Tidal Forces on Clouds
• Cosmic-ray driven outflow from the galactic center and the origin of magnetized radio filaments
• Towards Self-Consistent Modelling of the Sgr A* Accretion Flow: Linking Theory and Observation
• Evidence for a jet and outflow from Sgr A*: a continuum and spectral line study
• ALMA Detection of Bipolar Outflows: Evidence for Low Mass Star Formation within 1pc of Sgr A*
• A Deep Chandra View of A Candidate Parsec-Scale Jet from the Galactic Center Super-massive Black Hole
• A Nonthermal Radio Filament Connected to the Galactic Black Hole?
• ALMA and VLA observations of emission from the environment of Sgr A*
• ALMA Detection of Extreme Blue-Shifted Ionized Gas Within 0.2 pc of Sgr A* from -480 to -300 km/s
• Detection of a dense group of hyper-compact radio sources in the central parsec of the Galaxy
• Nonthermal filaments from the tidal destruction of clouds in the Galactic center
• Tidal Distortion of the Envelope of an AGB Star IRS 3 near Sgr A*