Radio Continuum Observations of the Galactic Center: Photoevaporative Proplyd-like Objects near Sgr A*

Abstract

We present radio images within 30${}^{\prime \prime }$ of Sgr A* based on recent VLA observations at 34 GHz with 7.8 microJy sensitivity and resolution $\sim 88\times 46$ milliarcseconds (mas). We report 44 partially resolved compact sources clustered in two regions in the E arm of ionized gas that orbits Sgr A*. These sources have size scales ranging between ~50 and 200 mas (400 to 1600 AUs), and a bow-shock appearance facing the direction of Sgr A*. Unlike the bow-shock sources previously identified in the near-IR but associated with massive stars, these 34 GHz sources do not appear to have near-IR counterparts at 3.8 $\mu$m. We interpret these sources as a candidate population of photoevaporative protoplanetary disks (proplyds) that are associated with newly formed low mass stars with mass loss rates ~10^{-7} - 10^{-6} solar mass per year and are located at the edge of a molecular cloud outlined by ionized gas. The disks are externally illuminated by strong Lyman continuum radiation from the ~100 OB and WR massive stars distributed within 10'' of Sgr A*. The presence of proplyds implies current in-situ star formation activity near Sgr A* and opens a window for the first time to study low mass star, planetary and brown dwarf formations near a supermassive black hole.

arXiv comment13 pages, 4 figures, ApJL (in press)

References in corpus (22)

• 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 Galactic Center Massive Black Hole and Nuclear Star Cluster
• The Proper Motion of Sgr A*: II. The Mass of Sgr A*
• The Two Young Star Disks in the Central Parsec of the Galaxy: Properties, Dynamics and Formation
• An Extremely Top-Heavy IMF in the Galactic Center Stellar Disks
• A Disk of Young Stars at the Galactic Center as Determined by Individual Stellar Orbits
• Stellar Populations in the Central 0.5 pc of the Galaxy II: The Initial Mass Function
• Swift Discovery of a New Soft Gamma Repeater, SGR J1745-29, near Sagittarius A*
• ALMA Observations of the Orion Proplyds
• Near-infrared proper motions and spectroscopy of infrared excess sources at the Galactic Center
• Stellar Bowshocks in the Northern Arm of the Galactic Center: More Members and Kinematics of the Massive Star Population
• Holographic Imaging of Crowded Fields: High Angular Resolution Imaging with Excellent Quality at Very Low Cost
• A survey of SiO 5-4 emission towards outflows from low-luminosity protostellar candidates
• Dusty Sources at the Galactic Center: The N- and Q-band view with VISIR
• IRS 13N: a new comoving group of sources at the Galactic Center
• ALMA Observations of the Galactic Center: SiO Outflows and High Mass Star Formation near Sgr A*
• Properties of bow-shock sources at the Galactic center
• HST and UKIRT Observations of the Center of the Trifid Nebula: Evidence for the Photoevaporation of a Proplyd and a Protostellar Condensation
• The Discovery of Radio Stars within 10 arcseconds of Sgr A* at 7mm
• VLTI observations of IRS~3: The brightest compact MIR source at the Galactic Centre
• Imprints of Molecular Clouds in Radio Continuum Images

Cited by in corpus (49)

• Star formation is boosted (and quenched) from the inside out: radial star formation profiles from MaNGA
• Bar quenching in gas-rich galaxies
• Jekyll & Hyde: quiescence and extreme obscuration in a pair of massive galaxies 1.5 Gyr after the Big Bang
• Enhanced atomic gas fractions in recently merged galaxies: quenching is not a result of post-merger gas exhaustion
• The Nature of Massive Transition Galaxies in CANDELS, GAMA, and Cosmological Simulations
• External photoevaporation of circumstellar disks constrains the timescale for planet formation
• The origins of post-starburst galaxies at z<0.05
• Galaxy And Mass Assembly (GAMA): The mechanisms for quiescent galaxy formation at $z<1$
• The Cosmic Ultraviolet Baryon Survey (CUBS) I. Overview and the diverse environments of Lyman limit systems at z<1
• The structure of post-starburst galaxies at $0.5<z<2$: evidence for two distinct quenching routes at different epochs
• Evolution Through the Post-Starburst Phase: Using Post-Starburst Galaxies as Laboratories for Understanding the Processes that Drive Galaxy Evolution
• Post-Starburst Galaxies in SDSS-IV MaNGA
• Direct evidence of AGN-feedback: a post starburst galaxy stripped of its gas by AGN-driven winds
• Chronos and Kairos: Mosfire Observations of Post-Starburst Galaxies in z~1 Clusters and Groups
• The strong correlation between post-starburst fraction and environment
• Evolution of the cold gas properties of simulated post-starburst galaxies
• High-velocity outflows in massive post-starburst galaxies at z > 1
• Evidence of ongoing AGN-driven feedback in a quiescent post starburst E+A galaxy
• Multi-phase outflows in post starburst E+A galaxies -- II. A direct connection between the neutral and ionized outflow phases
• An ALMA view of star formation efficiency suppression in early-type galaxies after gas-rich minor mergers
• Compact Radio Sources within 30" of Sgr A*: Proper Motions, Stellar Winds and the Accretion Rate onto Sgr A*
• High Molecular-Gas to Dust Mass Ratios Predicted in Most Quiescent Galaxies
• Near-Infrared Variability Study of the Central 2.3 arcmin x 2.3 arcmin of the Galactic Centre II. Identification of RR Lyrae Stars in the Milky Way Nuclear Star Cluster
• The ALMaQUEST Survey: VI. The molecular gas main sequence of `retired' regions in galaxies
• ALMA Detection of Bipolar Outflows: Evidence for Low Mass Star Formation within 1pc of Sgr A*
• Rise and fall of post-starburst galaxies in Magneticum Pathfinder
• Polarized near-infrared light of the Dusty S-cluster Object (DSO/G2) at the Galactic Center
• From starburst to quiescence: post-starburst galaxies and their large-scale clustering over cosmic time
• AAS WorldWide Telescope: Seamless, Cross-Platform Data Visualization Engine for Astronomy Research, Education, and Democratizing Data
• Molecular Gas during the Post-Starburst Phase: Low Gas Fractions in Green Valley Seyfert Post-Starburst Galaxies
• ALMA View of the Galactic Center Mini-spiral: Ionized Gas Flows around Sagittarius A*
• Radio Stars: from kHz to THz
• Galactic Center Mini-spiral by ALMA - Possible Origin of the Central Cluster
• Three regimes of CO emission in galaxy mergers
• Effect of an isotropic outflow from the Galactic centre on the bow-shock evolution along the orbit
• Studying the [OIII]$\lambda$5007A emission-line width in a sample of $\sim$80 local active galaxies: A surrogate for ${\sigma }_{\star }$?
• A new bow-shock source with bipolar morphology in the vicinity of Sgr A*
• Forming circumnuclear disks and rings in galactic nuclei: a competition between supermassive black hole and nuclear star cluster
• Sgr A* and its Environment: Low Mass Star Formation, the Origin of X-ray Gas and Collimated Outflow
• High-speed molecular cloudlets around the Galactic Center supermassive black hole
• Radio Continuum Emission from the Magnetar SGR J1745-2900: Interaction with Gas Orbiting Sgr A*
• X3: a high-mass Young Stellar Object close to the supermassive black hole Sgr~A*
• 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*
• Radio observations of evaporating objects in the Cygnus OB2 region
• Tidally-disrupted Molecular Clouds falling to the Galactic Center
• Spatially resolved star formation relation in two HI-rich galaxies with central post-starburst signature
• Stability of planetary systems within the S-star cluster: the Solar system analogues
• The Fate of Binary Stars Hosting Planets upon Interaction with Sgr A* Black hole
• Star Formation Close to Sgr A* and Beyond the Nuclear Cluster