Probing the Halo Gas Distribution in the Inner Galaxy with Fermi Bubble Observations

Abstract

The hot halo gas distribution in the inner Milky Way (MW) contains key fossil records of the past energetic feedback processes in the Galactic center. Here we adopt a variety of spherical and disk-like MW halo gas models as initial conditions in a series of simulations to investigate the formation of the Fermi bubbles in the jet-shock scenario. The simulation results are compared directly with relevant X-ray and gamma-ray observations of the Fermi bubbles to constrain the halo gas distribution in the inner Galaxy before the Fermi bubble event. Our best-fit gas density distribution can be described by a power law in radius $n_{\mathrm{e}}(r)=0.01(r/1\text{ kpc}{)}^{-1.5}$ cm${}^{-3}$. Our study can not determine if there is an inner density core, which if exists, should be very small with size $r_c\lesssim 0.5$ kpc. When extrapolating to large radii $r\sim 50-90$ kpc, our derived density distribution lies appreciably below the recently estimated gas densities from ram-pressure stripping calculations, suggesting that the halo gas density profile either flattens out or has one or more discontinuities within $10\lesssim r\lesssim 50$ kpc. Some of these discontinuities may be related to the eROSITA bubbles, and our derived gas density profile may correspond to the hot gas distribution in the inner eROSITA bubbles about $5$ Myr ago.

arXiv comment16 pages, 12 figures. Accepted for publication ApJ

References in corpus (69)

• A Universal Density Profile from Hierarchical Clustering
• The Structure of Cold Dark Matter Halos
• How Do Galaxies Get Their Gas?
• Collisional Plasma Models with APEC/APED: Emission Line Diagnostics of Hydrogen-like and Helium-like Ions
• The Galaxy in Context: Structural, Kinematic and Integrated Properties
• The Circumgalactic Medium
• The mass distribution and gravitational potential of the Milky Way
• Giant Gamma-ray Bubbles from Fermi-LAT: AGN Activity or Bipolar Galactic Wind?
• Updated Atomic Data and Calculations for X-ray Spectroscopy
• Gaseous Galaxy Halos
• Multi-Phase Galaxy Formation: High Velocity Clouds and the Missing Baryon Problem
• HI in Local Group Dwarf Galaxies and Stripping by the Galactic Halo
• A high spatial resolution X-ray and H-alpha study of hot gas in the halos of star-forming disk galaxies. I. Spatial and spectral properties of the diffuse X-ray emission
• The Spectrum and Morphology of the Fermi Bubbles
• Locating the "missing" baryons with extragalactic dispersion measure estimates
• The Large-scale Bipolar Wind in the Galactic Center
• A huge reservoir of ionized gas around the Milky Way: Accounting for the Missing Mass?
• The Fermi Haze: A Gamma-Ray Counterpart to the Microwave Haze
• The Fermi Bubbles: Giant, Multi-Billion-Year-Old Reservoirs of Galactic Center Cosmic Rays
• Constraining the Milky Way's Hot Gas Halo with OVII and OVII Emission Lines
• Chandra Discovery of a Tree in the X-ray Forest towards PKS 2155-304: the Local Filament?
• Detection of large-scale X-ray bubbles in the Milky Way halo
• The Structure of the Milky Way's Hot Gas Halo
• X-ray gas density profile of clusters of galaxies from the universal dark matter halo
• The Fermi Bubbles. I. Possible Evidence for Recent AGN Jet Activity in the Galaxy
• The Effelsberg-Bonn HI Survey: Milky Way gas. First data release
• Energy Spectra of the Soft X-ray Diffuse Emission in Fourteen Fields Observed with Suzaku
• Detection of a Hot Gaseous Halo Around the Giant Spiral Galaxy NGC 1961
• Angular Momentum Acquisition in Galaxy Halos
• The Fermi Bubbles: Supersonic AGN Jets with Anisotropic Cosmic Ray Diffusion
• Ram Pressure Stripping of the Large Magellanic Cloud's Disk as a Probe of the Milky Way's Circumgalactic Medium
• Unveiling the corona of the Milky Way via ram-pressure stripping of dwarf satellites
• Massive Coronae of Galaxies
• An XMM-Newton Survey of the Soft X-ray Background. III. The Galactic Halo X-ray Emission
• Probing the Fermi Bubbles in Ultraviolet Absorption: A Spectroscopic Signature of the Milky Way's Biconical Nuclear Outflow
• On the Hot Gas Content of the Milky Way Halo
• Chandra Detection of a Hot Gaseous Corona Around the Edge-on Galaxy NGC 4631
• X-ray Absorption Line Spectroscopy of the Galactic Hot Interstellar Medium
• Fermi Bubbles Inflated by Winds Launched from the Hot Accretion Flow in Sgr A*
• Probing the Local Group Medium Toward Mkn 421 with Chandra and FUSE
• The Fermi Bubbles. II. The Potential Roles of Viscosity and Cosmic Ray Diffusion in Jet Models
• Spatial distribution of the Milky Way hot gaseous halo constrained by Suzaku X-ray observations
• The Fermi Bubbles as Starburst Wind Termination Shocks
• The Interaction of the Fermi Bubbles with the Milky Way's Hot Gas Halo
• Deviations from hydrostatic equilibrium in the circumgalactic medium: spinning hot haloes and accelerating flows
• The distribution of gas in the Local Group from constrained cosmological simulations: the case for Andromeda and the Milky Way galaxies
• Multi-wavelength features of Fermi Bubbles as signatures of a Galactic wind
• Ambient Column Densities of Highly Ionized Oxygen in Precipitation-Limited Circumgalactic Media
• The large-scale ionization cones in the Galaxy
• A disk-dominated and clumpy circumgalactic medium of the Milky Way seen in X-ray emission
• Exploring the dispersion measure of the Milky Way halo
• X-ray and Gamma-ray Observations of the Fermi Bubbles and NPS/Loop I Structures
• The Non-isothermality and Extent of Galactic Diffuse Hot Gas Toward Mrk~421
• Diffuse X-ray emission in spiral galaxies
• How Do Supernovae Impact the Circumgalactic Medium? I. Large-Scale Fountains Around a Milky Way-Like Galaxy
• Circumgalactic Oxygen Absorption and Feedback
• Simulating the Fermi Bubbles as Forward Shocks Driven by AGN Jets
• The Properties of the Galactic Hot Gaseous Halo from X-ray Emission
• The Fermi Bubbles as a Scaled-up Version of Supernova Remnants
• A Hadronic-Leptonic Model for the Fermi Bubbles: Cosmic-Rays in the Galactic Halo and Radio Emission
• Global Simulations of Galactic Discs: Violent Feedback from Clustered Supernovae during Bursts of Star Formation
• Models of rotating coronae
• Fermi bubble edges: spectrum and diffusion function
• Analytical and numerical studies of central galactic outflows powered by tidal disruption events -- a model for the Fermi bubbles?
• Diagnostics of Gaseous Halo of the Milky Way by a Shock Wave from the Galactic Centre
• Fermi bubbles: high latitude X-ray supersonic shell
• Constraining the Milky Way Mass with Its Hot Gaseous Halo
• MAXI/SSC All-sky maps from 0.7 keV to 4 keV
• On the Cooling Flow Problem in the Gaseous Halo of the Milky Way

Cited by in corpus (5)

• Revealing Gas Inflows towards the Galactic Central Molecular Zone
• Emission from hadronic and leptonic processes in galactic jet-driven bubbles
• QUIJOTE scientific results -- VI. The Haze as seen by QUIJOTE
• Galactic breeze origin for the Fermi bubbles emission
• Multi-wavelength emission from leptonic processes in ageing galaxy bubbles