Evidence for a large off-centered galactic outflow and its connection to the extraplanar diffuse ionized gas in IC 1553
arXiv:2308.15134 · doi:10.1051/0004-6361/202245679
Abstract
Aims. We analyze a MUSE optical integral field spectrum of the star-forming edge-on galaxy IC 1553 in order to study its extraplanar diffuse ionized gas (eDIG) and the processes shaping its disk-halo interface. Methods. We extracted the optical emission line properties from the integral field spectrum and generated the commonly used emission line diagnostic diagrams in order to analyze the ionization conditions and the distribution of the eDIG. Furthermore, we performed gravitational potential fitting to investigate the kinematics of a suspected galactic outflow. Results. We find that the eDIG scale height has a maximum value of approximately 1.0 kpc and decreases roughly linearly with the radial distance from the galactic center in projection. The ionization state of the eDIG is not consistent with a pure photoionization scenario and instead requires a significant contribution from shock ionization. This, in addition to the gas kinematics, strongly suggests the presence of a galactic scale outflow, the origin of which lies at least 1.4 kpc away from the galactic center. The inferred shock velocity in the eDIG of approximately 225 km s-1 is comparable to the escape velocity estimated from our potential modelling. The asymmetric distribution of currently star-forming clusters produces a range of different ionization conditions in the eDIG. As a result, the vertical emission line profiles vary quantitatively and qualitatively along the major axis of the galaxy. This analysis illustrates that it is crucial in studies of the eDIG to use observations that take the spatial and kinematical distributions into account, such as those done with integral field units, to form an accurate picture of the relevant physical properties.
Accepted for publication by Astronomy & Astrophysics on August 1, 2023
References in corpus (20)
- Overview of the SDSS-IV MaNGA Survey: Mapping Nearby Galaxies at Apache Point Observatory
- galpy: A Python Library for Galactic Dynamics
- Improving the full spectrum fitting method: accurate convolution with Gauss-Hermite functions
- The MAPPINGS III Library of Fast Radiative Shock Models
- UV-extended E-MILES stellar population models: young components in massive early-type galaxies
- Understanding Galaxy Evolution through Emission Lines
- APOGEE Data and Spectral Analysis from SDSS Data Release 16: Seven Years of Observations Including First Results from APOGEE-South
- The MUSE Hubble Ultra Deep Field Survey: I. Survey description, data reduction and source detection
- The Rapid ASKAP Continuum Survey I: Design and First Results
- CALIFA, the Calar Alto Legacy Integral Field Area survey. III. Second public data release
- The Turbulent Warm Ionized Medium: Emission Measure Distribution and MHD Simulations
- A Review of Recent Observations of Galactic Winds Driven by Star Formation
- The MUSE Atlas of Disks (MAD): Resolving Star Formation Rates and Gas Metallicities on < 100pc Scales
- A kinematic study of the irregular dwarf galaxy NGC 2366 using HI and Halpha observations
- SDSS IV MaNGA: Deep observations of extra-planar, diffuse ionized gas around late-type galaxies from stacked IFU spectra
- Catastrophic Cooling in Superwinds: Line Emission and Non-equilibrium Ionization
- The kinematics of local thick discs do not support an accretion origin
- The multifarious ionization sources and disturbed kinematics of extraplanar gas in five low-mass galaxies
- Outflow or galactic wind: The fate of ionized gas in the halos of dwarf galaxies
- Non-equilibrium Ionization States Within Galactic Outflows: Explaining Their O VI and N V Column Densities