The Galactic Center Cloud G2 -- a Young Low-Mass Star with a Stellar Wind

Abstract

We explore the possibility that the G2 gas cloud falling in towards \sgra is the mass loss envelope of a young TTauri star. As the star plunges to smaller radius at 1000 to 6000 \kms, a strong bow shock forms where the stellar wind is impacted by the hot X-ray emitting gas in the vicinity of \sgra. For a stellar mass loss rate of $4\times 10^{-8}$ \msun per yr and wind velocity 100 \kms, the bow shock will have an emission measure ($EM=n^{2}vol$) at a distance $\sim 10^{16}$ cm, similar to that inferred from the IR emission lines. The ionization of the dense bow shock gas is potentially provided by collisional ionization at the shock front and cooling radiation (X-ray and UV) from the post shock gas. The former would predict a constant line flux as a function of distance from \sgra, while the latter will have increasing emission at lesser distances. In this model, the star and its mass loss wind should survive pericenter passage since the wind is likely launched at 0.2 AU and this is much less than the Roche radius at pericenter ($\sim 3$ AU for a stellar mass of 2\msun). In this model, the emission cloud will probably survive pericenter passage, discriminating this scenario from others.

References in corpus (3)

• Near-infrared proper motions and spectroscopy of infrared excess sources at the Galactic Center
• New observations of the gas cloud G2 in the Galactic Center
• A nova origin of the gas cloud at the Galactic Center ?

Cited by in corpus (56)

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• Stellar transits across a magnetized accretion torus as a mechanism for plasmoid ejection
• Secular Evolution Of Binaries Near Massive Black Holes: Formation of compact binaries, merger/collision products and G2-like objects
• Pericenter passage of the gas cloud G2 in the Galactic Center
• Keck Observations of the Galactic Center Source G2: Gas Cloud or Star?
• A population of dust-enshrouded objects orbiting the Galactic black hole
• Hydrodynamical simulations of a compact source scenario for the Galactic Center cloud G2
• Monitoring the Dusty S-Cluster Object (DSO/G2) on its Orbit towards the Galactic Center Black Hole
• Recurring flares from supermassive black hole binaries: implications for tidal disruption candidates and OJ 287
• Possible Origin of the G2 Cloud from the Tidal Disruption of a Known Giant Star by Sgr A*
• The Post-Periapse Evolution of Galactic Center Source G1: The second case of a resolved tidal interaction with a supermassive black hole
• Dust-enshrouded star near supermassive black hole: predictions for high-eccentricity passages near low-luminosity galactic nuclei
• Star Formation in the vicinity of Nuclear Black Holes: Young Stellar Objects close to Sgr A*
• The Post-Pericenter Evolution of the Galactic Center Source G2
• Flaring up of the Compact Cloud G2 during the Close Encounter with Sgr A*
• Spitzer/IRAC Observations of the Variability of Sgr A* and the Object G2 at 4.5 microns
• Clump formation through colliding stellar winds in the Galactic Centre
• The role of feedback in accretion on Low Luminosity AGN: Sgr A* case study
• The Properties and Fate of the Galactic Center G2 Cloud
• Monitoring dusty sources in the vicinity of Sgr A*
• Nature of the Galactic centre NIR-excess sources. I. What can we learn from the continuum observations of the DSO/G2 source?
• Supernova Kicks and Dynamics of Compact Remnants in the Galactic Centre
• Polarized near-infrared light of the Dusty S-cluster Object (DSO/G2) at the Galactic Center
• A Stellar Wind Origin for the G2 Cloud: Three-Dimensional Numerical Simulations
• Star Formation and Dynamics in the Galactic Centre
• Radio Synchrotron Emission from the Bow Shock of G2
• 3D adaptive mesh refinement simulations of the gas cloud G2 born within the disks of young stars in the Galactic Center
• Effect of an isotropic outflow from the Galactic centre on the bow-shock evolution along the orbit
• A new bow-shock source with bipolar morphology in the vicinity of Sgr A*
• No asymmetric outflows from Sagittarius A* during the pericenter passage of the gas cloud G2
• A binary system in the S cluster close to the supermassive black hole Sagittarius A*
• Constraining the accretion flow density profile near Sgr A* using the $L^{\prime }$-band emission of the S2 star
• The apparent tail of the Galactic center object G2/DSO
• Sgr A* and its Environment: Low Mass Star Formation, the Origin of X-ray Gas and Collimated Outflow
• The evolution of circumstellar discs in the Galactic Centre: an application to the G-clouds
• Monitoring the Galactic Centre with Australia Telescope Compact Array
• No Microwave Flare of Sagittarius A* around the G2 Periastron Passing
• Polarization simulations of stellar wind bow shock nebulae. II. The case of dust scattering
• X3: a high-mass Young Stellar Object close to the supermassive black hole Sgr~A*
• Detecting Stars at the Galactic Centre via Synchrotron Emission
• Signatures of an Encounter Between the G2 Cloud and a Jet from Sgr A*
• $G$ Objects and primordial black holes
• The G2+G2t complex as a fast and massive outflow?
• Candidate Young Stellar Objects in the S-cluster: The Kinematic Analysis of a Sub-population of the Low-mass G-objects close to Sgr A*
• Probing the Gas Density in our Galactic Center: Moving Mesh Simulations of G2
• 3D AMR hydrosimulations of a compact source scenario for the Galactic Centre cloud G2
• The Keplerian orbit of G2
• Colliding with G2 near the Galactic Centre: a geometrical approach
• The Galactic Center Black Hole Laboratory
• Hydrodynamical simulations of a compact source scenario for G2
• The dynamics of S-stars and G-sources orbiting a supermassive compact object made of fermionic dark matter
• The gas streamer G1-2-3 in the Galactic Center
• Theory of G2 Cloud Multi-Wavelength Emission
• 3D AMR simulations of G2 as an outflow