"Characterizing the Interstellar Medium at the Galactic Center: The Role of Magnetic and Stellar Feedback"
ESO Star and Planet Formation Seminar
- Date: Apr 14, 2026
- Time: 10:00 AM - 11:00 AM (Local Time Germany)
- Speaker: Farideh Mazoochi (IPM)
- Location: ESO Garching
- Room: Auditorium Telescopium (ESO HQE, Garching)
Abstract:
The Galactic Center (GC) offers a unique opportunity to study the complex interstellar medium and star formation in a galactic nucleus with high resolution.
In the circumnuclear disk (CND) near SgrA*, using MeerKAT 1.3 GHz continuum and ALMA H40α data from ACES at ~0.2 pc resolution, we separate thermal and nonthermal emission, finding a thermal fraction of ~13%. The equipartition magnetic fields correlate with JCMT CO (J = 3→2) observations data in this region, indicating a pressure balance between magnetic fields, cosmic rays, and molecular gas. While ionized gas and magnetic fields persist, molecular gas density drops within R≤2pc, likely due to feedback from Sgr A*. We find that nonthermal pressure from turbulence balances magnetic and cosmic-ray pressures, exceeding thermal pressure by two orders of magnitude. The environment is characterized by a low thermal-to-magnetic energy ratio, supersonic plasma with an Alfvén Mach number of ≃ 4. A subcritical mass-to-magnetic flux ratio suggests that magnetic fields stabilize the CND against gravitational collapse.
Further from Sgr A*, we are studying the extended ionized gas in Sgr B1, a specific HII region in the GC, to investigate gas kinematics and star-formation feedback.
The Galactic Center (GC) offers a unique opportunity to study the complex interstellar medium and star formation in a galactic nucleus with high resolution.
In the circumnuclear disk (CND) near SgrA*, using MeerKAT 1.3 GHz continuum and ALMA H40α data from ACES at ~0.2 pc resolution, we separate thermal and nonthermal emission, finding a thermal fraction of ~13%. The equipartition magnetic fields correlate with JCMT CO (J = 3→2) observations data in this region, indicating a pressure balance between magnetic fields, cosmic rays, and molecular gas. While ionized gas and magnetic fields persist, molecular gas density drops within R≤2pc, likely due to feedback from Sgr A*. We find that nonthermal pressure from turbulence balances magnetic and cosmic-ray pressures, exceeding thermal pressure by two orders of magnitude. The environment is characterized by a low thermal-to-magnetic energy ratio, supersonic plasma with an Alfvén Mach number of ≃ 4. A subcritical mass-to-magnetic flux ratio suggests that magnetic fields stabilize the CND against gravitational collapse.
Further from Sgr A*, we are studying the extended ionized gas in Sgr B1, a specific HII region in the GC, to investigate gas kinematics and star-formation feedback.