Ackermann M, Albert A, Atwood WB, Baldini L, Ballet J, Barbiellini G, Bastieri D, Bellazzini R, Bissaldi E, Blandford RD, Bloom ED, Bottacini E, Brandt TJ, Bregeon J, Bruel P, Buehler R, Buson S, Caliandro GA, Cameron RA, Caragiulo M, Caraveo PA, Cavazzuti E, Cecchi C, Charles E, Chekhtman A, Chiang J, Chiaro G, Ciprini S, Claus R, Cohen-Tanugi J, Conrad J, Cutini S, D'Ammando F, de Angelis A, de Palma F, Dermer CD, Digel SW, Di Venere L, do Couto e Silva E, Drell PS, Favuzzi C, Ferrara EC, Focke WB, Franckowiak A, Fukazawa Y, Funk S, Fusco P, Gargano F, Gasparrini D, Germani S, Giglietto N, Giordano F, Giroletti M, Godfrey G, Gomez-Vargas GA, Grenier IA, Guiriec S, Hadasch D, Harding AK, Hays E, Hewitt JW, Hou X, Jogler T, Johannesson G, Johnson AS, Johnson WN, Kamae T, Kataoka J, Knoedlseder J, Kocevski D, Kuss M, Larsson S, Latronico L, Longo F, Loparco F, Lovellette MN, Lubrano P, Malyshev D, Manfreda A, Massaro F, Mayer M, Mazziotta MN, McEnery JE, Michelson PF, Mitthumsiri W, Mizuno T, Monzani ME, Morselli A, Moskalenko IV, Murgia S, Nemmen R, Nuss E, Ohsugi T, Omodei N, Orienti M, Orlando E, Ormes JF, Paneque D, Panetta JH, Perkins JS, Pesce-Rollins M, Petrosian V, Piron F, Pivato G, Raino S, Rando R, Razzano M, Razzaque S, Reimer A, Reimer O, Sanchez-Conde M, Schaal M, Schulz A, Sgro C, Siskind EJ, Spandre G, Spinelli P, Stawarz L, Strong AW, Suson DJ, Tahara M, Takahashi H, Thayer JB, Tibaldo L, Tinivella M, Torres DF, Tosti G, Troja E, Uchiyama Y, Vianello G, Werner M, Winer BL, Wood KS, Wood M, Zaharijas G (2014)

Publication Status: Published

Publication Type: Journal article

Publication year: 2014


Publisher: American Astronomical Society

Book Volume: 793

DOI: 10.1088/0004-637X/793/1/64


The Fermi bubbles are two large structures in the gamma-ray sky extending to 55 degrees above and below the Galactic center. We analyze 50 months of Fermi Large Area Telescope data between 100MeV and 500 GeV above 10 degrees in Galactic latitude to derive the spectrum and morphology of the Fermi bubbles. We thoroughly explore the systematic uncertainties that arise when modeling the Galactic diffuse emission through two separate approaches. The gamma-ray spectrum is well described by either a log parabola or a power law with an exponential cutoff. We exclude a simple power law with more than 7 sigma significance. The power law with an exponential cutoff has an index of 1.9 +/- 0.2 and a cutoff energy of 110 +/- 50 GeV. We find that the gamma-ray luminosity of the bubbles is 4.4(-0.9)(+2.4) x 10(37) erg s(-1). We confirm a significant enhancement of gamma-ray emission in the southeastern part of the bubbles, but we do not find significant evidence for a jet. No significant variation of the spectrum across the bubbles is detected. The width of the boundary of the bubbles is estimated to be 3.4(-2.6)(+3.7) deg. Both inverse Compton (IC) models and hadronic models including IC emission from secondary leptons fit the gamma-ray data well. In the IC scenario, synchrotron emission from the same population of electrons can also explain the WMAP and Planck microwave haze with a magnetic field between 5 and 20 mu G.

Authors with CRIS profile

Involved external institutions

Deutsches Elektronen-Synchrotron DESY DE Germany (DE) Stanford University US United States (USA) (US) Leopold-Franzens-Universität Innsbruck / University of Innsbruck AT Austria (AT) Ohio State University US United States (USA) (US) National Institute for Astrophysics / Istituto Nazionale Astrofisica (INAF) IT Italy (IT) National Institute for Nuclear Physics / Istituto Nazionale di Fisica Nucleare (INFN) IT Italy (IT) University of Montpellier / Université Montpellier FR France (FR) Italian Space Agency / Agenzia Spaziale Italiana (ASI) IT Italy (IT) Hiroshima University / 広島大学 JP Japan (JP) University of Udine / Università degli Studi di Udine IT Italy (IT) Politecnico di Bari IT Italy (IT) University of California Santa Cruz US United States (USA) (US) University of Maryland, Baltimore County (UMBC) US United States (USA) (US) National Aeronautics and Space Administration (NASA) US United States (USA) (US) U.S. Naval Research Laboratory US United States (USA) (US) Yale University US United States (USA) (US) Mahidol University / มหาวิทยาลัยมหิดล TH Thailand (TH) University of California Irvine US United States (USA) (US) University of Johannesburg ZA South Africa (ZA) National Academy of Sciences US United States (USA) (US) Japan Aerospace eXploration Agency (JAXA) JP Japan (JP) Waseda University / 早稲田大学 JP Japan (JP) Spanish National Research Council / Consejo Superior de Investigaciones Científicas (CSIC) ES Spain (ES) Max-Planck-Institut für extraterrestrische Physik (MPE) / Max Planck Institute for Extraterrestrial Physics DE Germany (DE) University of Padua / Universita degli Studi di Padova IT Italy (IT) Stockholm University / Stockholms universitet SE Sweden (SE) National Center for Scientific Research / Centre national de la recherche scientifique (CNRS) FR France (FR) NYCB Real-Time Computing, Inc. US United States (USA) (US) University of Paris 7 - Denis Diderot / Université Paris VII Denis Diderot FR France (FR) Université Bordeaux 1, Sciences et Technologies FR France (FR) George Mason University US United States (USA) (US) École Polytechnique - Université Paris-Saclay FR France (FR) University of Denver US United States (USA) (US) Purdue University Northwest / Purdue University Calumet US United States (USA) (US) University of Iceland (UI) / Háskóli Íslands IS Iceland (IS)

How to cite


Ackermann, M., Albert, A., Atwood, W.B., Baldini, L., Ballet, J., Barbiellini, G.,... Zaharijas, G. (2014). THE SPECTRUM AND MORPHOLOGY OF THE FERMI BUBBLES. Astrophysical Journal, 793.


Ackermann, M., et al. "THE SPECTRUM AND MORPHOLOGY OF THE FERMI BUBBLES." Astrophysical Journal 793 (2014).

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