Related Experiment Video
Updated: Jul 9, 2025
11:20
Investigation of Early Plasma Evolution Induced by Ultrashort Laser Pulses
Published on: July 2, 2012
15.0K
Bipolar outflows out to 10 kpc for massive galaxies at redshift z ≈ 1
Yucheng Guo1, Roland Bacon2, Nicolas F Bouché2
1Univ Lyon, Univ Lyon1, Ens de Lyon, CNRS, Centre de Recherche Astrophysique de Lyon UMR5574, Saint-Genis-Laval, France. yucheng.guo@univ-lyon1.fr.
Nature
|December 6, 2023
Summary
Galactic outflows, crucial for galaxy evolution, were observed using MUSE. Edge-on galaxies showed enhanced Mg II emission, supporting bipolar outflow shapes extending over 10 kpc into the circumgalactic medium.
Area of Science:
- Astronomy and Astrophysics
- Galaxy Evolution Studies
- Cosmic Gas Dynamics
Background:
- Galactic outflows regulate galaxy mass and star formation.
- Theoretical models predict bipolar outflows extending into the circumgalactic medium (CGM).
- Observing high-redshift outflows is challenging due to low density and surface brightness.
Purpose of the Study:
- To investigate the presence and geometry of galactic outflows at higher redshifts (z ≈ 1).
- To test theoretical predictions of bipolar outflow shapes.
- To determine the prevalence of CGM-scale outflows in massive galaxies.
Main Methods:
- Utilized an ultra-deep Multi-Unit Spectroscopic Explorer (MUSE) image.
- Analyzed mean Mg II emission surrounding a sample of galaxies at z ≈ 1.
- Correlated observed emission with galaxy inclination and stellar mass.
Main Results:
- Detected Mg II emission suggesting outflowing gas on scales > 10 kpc.
- Observed enhanced emission along the minor axis for edge-on galaxies.
- Found weaker, isotropic emission for face-on galaxies, indicating a bipolar geometry.
Conclusions:
- The findings support the hypothesis of bipolar cone-shaped outflows perpendicular to the galactic disk.
- CGM-scale outflows appear prevalent in galaxies with stellar mass ≳ 10^9.5 M☉.
- This study provides observational evidence for outflow geometry in distant galaxies.
Related Concept Videos
01:21Schwarzschild Radius and Event Horizon
2.0K
No object with a finite mass can travel faster than the speed of light in a vacuum. This fact has an interesting consequence in the domain of extremely high gravitational fields.
The minimum speed required to launch a projectile from the surface of an object to which it is gravitationally bound so that it eventually escapes the object’s gravitational field is called the escape velocity. The escape velocity is independent of the mass of the object. Merging the idea of escape...
The minimum speed required to launch a projectile from the surface of an object to which it is gravitationally bound so that it eventually escapes the object’s gravitational field is called the escape velocity. The escape velocity is independent of the mass of the object. Merging the idea of escape...
2.0K
01:26Divergence and Curl of Magnetic Field
3.0K
The magnetic field due to a volume current distribution given by the Biot–Savart Law can be expressed as follows:
3.0K
01:10Detection of Black Holes
2.2K
Although black holes were theoretically postulated in the 1920s, they remained outside the domain of observational astronomy until the 1970s.
Their closest cousins are neutron stars, which are composed almost entirely of neutrons packed against each other, making them extremely dense. A neutron star has the same mass as the Sun but its diameter is only a few kilometers. Therefore, the escape velocity from their surface is close to the speed of light.
Not until the 1960s, when the first neutron...
Their closest cousins are neutron stars, which are composed almost entirely of neutrons packed against each other, making them extremely dense. A neutron star has the same mass as the Sun but its diameter is only a few kilometers. Therefore, the escape velocity from their surface is close to the speed of light.
Not until the 1960s, when the first neutron...
2.2K
01:19Magnetic Field Lines
4.1K
The representation of magnetic fields by magnetic field lines is very useful in visualizing the strength and direction of the magnetic field. Each of the magnetic field lines forms a closed loop. The field lines emerge from the north pole (N), loop around to the south pole (S), and continue through the bar magnet back to the north pole.
Magnetic field lines follow several hard-and-fast rules:
Magnetic field lines follow several hard-and-fast rules:
4.1K
01:29Potential Due to a Polarized Object
415
A neutral atom consists of a positively charged nucleus surrounded by a negatively charged electron cloud. When placed in an external electric field, the external electric force pulls the electrons and nucleus apart, opposite to the intrinsic attraction between the nucleus and the electrons. The opposing forces balance each other with a slight shift between the center of masses of the nucleus and the electron cloud, resulting in a polarized atom. On the other hand, a few molecules, like water,...
415
01:28Magnetostatic Boundary Conditions
955
An electric field suffers a discontinuity at a surface charge. Similarly, a magnetic field is discontinuous at a surface current. The perpendicular component of a magnetic field is continuous across the interface of two magnetic mediums. In contrast, its parallel component, perpendicular to the current, is discontinuous by the amount equal to the product of the vacuum permeability and the surface current. Like the scalar potential in electrostatics, the vector potential is also continuous...
955