GIANT GAMMA-RAY BUBBLES FROM FERMI-LAT: ACTIVE GALACTIC NUCLEUS ACTIVITY OR BIPOLAR GALACTIC WIND?

By M. Su, T. Slatyer, Douglas P. Finkbeiner. 2010

750 citations recorded by the source corpus.

Data from the Fermi-LAT reveal two large gamma-ray bubbles, extending 50° above and below the Galactic center (GC), with a width of about 40° in longitude. The gamma-ray emission associated with these bubbles has a significantly harder spectrum (dN/dE ∼ E−2) than the inverse Compton emission from electrons in the Galactic disk, or the gamma rays produced by the decay of pions from proton–interstellar medium collisions. There is no significant spatial variation in the spectrum or gamma-ray intensity within the bubbles, or between the north and south bubbles. The bubbles are spatially correlated with the hard-spectrum microwave excess known as the WMAP haze; the edges of the bubbles also line up with features in the ROSAT X-ray maps at 1.5–2 keV. We argue that these Galactic gamma-ray bubbles were most likely created by some large episode of energy injection in the GC, such as past accretion events onto the central massive black hole, or a nuclear starburst in the last ∼10 Myr. Dark matter annihilation/decay seems unlikely to generate all the features of the bubbles and the associated signals in WMAP and ROSAT; the bubbles must be understood in order to use measurements of the diffuse gamma-ray emission in the inner Galaxy as a probe of dark matter physics. Study of the origin and evolution of the bubbles also has the potential to improve our understanding of recent energetic events in the inner Galaxy and the high-latitude cosmic ray population.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/e505e2cd58866316f6b8a95d9b31b7ee8b128a57

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

In Nuclear and High Energy Physics

Citations in the corpus

THE SPECTRUM OF ISOTROPIC DIFFUSE GAMMA-RAY EMISSION BETWEEN 100 MeV AND 820 GeV (2014, background): “Dobler et al. (2010) and Su et al. (2010) have noted the existence of large-scale structures of residual diffuse γ-ray emission above and below the Galactic center region that became well known as the ‘Fermi Bubbles’.”
THE FIRST FERMI LAT SUPERNOVA REMNANT CATALOG (2015, background): “The standard IEM accounts for some extended remaining residuals including, notably, Loop I (Casandjian et al. 2009) and the Fermi bubbles (Su et al. 2010), as additional components.”
Galactic Center gamma-ray ``excess'' from an active past of the Galactic Centre? (2014, background): “[33] contains a description of these features as well as a nice review of different evidence for variability at the GC.”
Fermi 130 GeV gamma-ray excess and dark matter annihilation in sub-haloes and in the Galactic centre (2012, background): “This would open a possibility to explain the excess with astrophysical sources, for example with an unknown mechanism associated with the Fermi bubbles [8].”
Hot Accretion Flows Around Black Holes (2014, background): “The two Fermi bubbles detected above and below the Galactic center (Su et al. 2010) are also thought to be inflated by a jet or wind from Sgr A* during a period of activity in the last few million years (Zubovas et al. 2011, Guo & Mathews 2012).”
2FHL: THE SECOND CATALOG OF HARD FERMI-LAT SOURCES (2015, background): “The count map reported in Figure 1 shows that Fermi-LATobserves many point-like sources and large-scale diffuse emission in the direction of our Galaxy, some of which appears coincident with the so-called Fermi bubbles (Su et al. 2010; Ackermann et al. 2014b).”
Powerful Outflows and Feedback from Active Galactic Nuclei (2015, background): “Zubovas et al. (2011) suggest that the gamma–ray emitting bubbles disposed symmetrically about the plane of the Milky Way (Su et al. 2010) may be the remnants of a relatively recent and rather weak event like this.”
CLEARING OUT A GALAXY (2012, background): “The outflows are therefore directly comparable with the gamma–ray emitting bubbles in our Galaxy recently discovered by Fermi (Su et al. 2010).”
Quasar feedback and the origin of radio emission in radio-quiet quasars (2014, background): “In our Galaxy not only X-rays are observed (Sofue 2000), but the structures as seen in gamma-rays and are known as “the Fermi bubbles” (Su et al. 2010).”
The physics of galactic winds driven by active galactic nuclei (2012, background): “Fermi9 also recently detected bubbles of a similar scale in our Galaxy, clearly originating from the Galactic Center (Dobler et al. 2010; Su et al. 2010).”
Active galactic nuclei flicker: an observational estimate of the duration of black hole growth phases of ∼105 yr (2015, background): “Bland-Hawthorn et al. (2013) propose this Galactic Center outburst as the cause of the Fermi bubble (Su et al. 2010).”