Wild at Heart: The particle astrophysics of the Galactic Centre

R. M. Crocker, D. I. Jones, F. Aharonian, C. J. Law, F. Melia, Tomoharu Oka, J. Ott

研究成果: Article

94 引用 (Scopus)

抄録

We consider the high-energy astrophysics of the inner ∼200pc of the Galaxy. Our modelling of this region shows that the supernovae exploding here every few thousand years inject enough power to (i) sustain the steady-state, in situ population of cosmic rays (CRs) required to generate the region's non-thermal radio and TeV γ-ray emission; (ii) drive a powerful wind that advects non-thermal particles out of the inner Galactic Centre; (iii) supply the low-energy CRs whose Coulombic collisions sustain the temperature and ionization rate of the anomalously warm envelope detected throughout the Central Molecular Zone; (iv) accelerate the primary electrons which provide the extended, non-thermal radio emission seen over ∼150pc scales above and below the plane (the Galactic Centre lobe); and (v) accelerate the primary protons and heavier ions which, advected to very large scales (up to ∼10kpc), generate the recently identified Wilkinson Microwave Anisotropy Probe (WMAP) haze and corresponding Fermi haze/bubbles. Our modelling bounds the average magnetic field amplitude in the inner few degrees of the Galaxy to the range 60 < B/μ G < 40 0 (at 2σ confidence) and shows that even TeV CRs likely do not have time to penetrate into the cores of the region's dense molecular clouds before the wind removes them from the region. This latter finding apparently disfavours scenarios in which CRs - in this starburst-like environment - act to substantially modify the conditions of star formation. We speculate that the wind we identify plays a crucial role in advecting low-energy positrons from the Galactic nucleus into the bulge, thereby explaining the extended morphology of the 511keV line emission. We present extensive appendices reviewing the environmental conditions in the Galactic Centre, deriving the star formation and supernova rates there, and setting out the extensive prior evidence that exists, supporting the notion of a fast outflow from the region.

元の言語English
ページ(範囲)763-788
ページ数26
ジャーナルMonthly Notices of the Royal Astronomical Society
413
発行部数2
DOI
出版物ステータスPublished - 2011 5

Fingerprint

astrophysics
cosmic rays
cosmic ray
haze
supernovae
star formation
galaxies
galactic nuclei
Microwave Anisotropy Probe
reviewing
radio
energy
radio emission
molecular clouds
lobes
confidence
positrons
rays
heavy ions
envelopes

ASJC Scopus subject areas

  • Space and Planetary Science
  • Astronomy and Astrophysics

これを引用

Wild at Heart : The particle astrophysics of the Galactic Centre. / Crocker, R. M.; Jones, D. I.; Aharonian, F.; Law, C. J.; Melia, F.; Oka, Tomoharu; Ott, J.

:: Monthly Notices of the Royal Astronomical Society, 巻 413, 番号 2, 05.2011, p. 763-788.

研究成果: Article

Crocker, R. M. ; Jones, D. I. ; Aharonian, F. ; Law, C. J. ; Melia, F. ; Oka, Tomoharu ; Ott, J. / Wild at Heart : The particle astrophysics of the Galactic Centre. :: Monthly Notices of the Royal Astronomical Society. 2011 ; 巻 413, 番号 2. pp. 763-788.
@article{162a5f8574574965804e4de4d7b3c2a2,
title = "Wild at Heart: The particle astrophysics of the Galactic Centre",
abstract = "We consider the high-energy astrophysics of the inner ∼200pc of the Galaxy. Our modelling of this region shows that the supernovae exploding here every few thousand years inject enough power to (i) sustain the steady-state, in situ population of cosmic rays (CRs) required to generate the region's non-thermal radio and TeV γ-ray emission; (ii) drive a powerful wind that advects non-thermal particles out of the inner Galactic Centre; (iii) supply the low-energy CRs whose Coulombic collisions sustain the temperature and ionization rate of the anomalously warm envelope detected throughout the Central Molecular Zone; (iv) accelerate the primary electrons which provide the extended, non-thermal radio emission seen over ∼150pc scales above and below the plane (the Galactic Centre lobe); and (v) accelerate the primary protons and heavier ions which, advected to very large scales (up to ∼10kpc), generate the recently identified Wilkinson Microwave Anisotropy Probe (WMAP) haze and corresponding Fermi haze/bubbles. Our modelling bounds the average magnetic field amplitude in the inner few degrees of the Galaxy to the range 60 < B/μ G < 40 0 (at 2σ confidence) and shows that even TeV CRs likely do not have time to penetrate into the cores of the region's dense molecular clouds before the wind removes them from the region. This latter finding apparently disfavours scenarios in which CRs - in this starburst-like environment - act to substantially modify the conditions of star formation. We speculate that the wind we identify plays a crucial role in advecting low-energy positrons from the Galactic nucleus into the bulge, thereby explaining the extended morphology of the 511keV line emission. We present extensive appendices reviewing the environmental conditions in the Galactic Centre, deriving the star formation and supernova rates there, and setting out the extensive prior evidence that exists, supporting the notion of a fast outflow from the region.",
keywords = "Cosmic rays, Galaxies: star formation, Galaxy: centre, ISM: jets and outflows, ISM: supernova remnants, Radiation mechanisms: non-thermal",
author = "Crocker, {R. M.} and Jones, {D. I.} and F. Aharonian and Law, {C. J.} and F. Melia and Tomoharu Oka and J. Ott",
year = "2011",
month = "5",
doi = "10.1111/j.1365-2966.2010.18170.x",
language = "English",
volume = "413",
pages = "763--788",
journal = "Monthly Notices of the Royal Astronomical Society",
issn = "0035-8711",
publisher = "Oxford University Press",
number = "2",

}

TY - JOUR

T1 - Wild at Heart

T2 - The particle astrophysics of the Galactic Centre

AU - Crocker, R. M.

AU - Jones, D. I.

AU - Aharonian, F.

AU - Law, C. J.

AU - Melia, F.

AU - Oka, Tomoharu

AU - Ott, J.

PY - 2011/5

Y1 - 2011/5

N2 - We consider the high-energy astrophysics of the inner ∼200pc of the Galaxy. Our modelling of this region shows that the supernovae exploding here every few thousand years inject enough power to (i) sustain the steady-state, in situ population of cosmic rays (CRs) required to generate the region's non-thermal radio and TeV γ-ray emission; (ii) drive a powerful wind that advects non-thermal particles out of the inner Galactic Centre; (iii) supply the low-energy CRs whose Coulombic collisions sustain the temperature and ionization rate of the anomalously warm envelope detected throughout the Central Molecular Zone; (iv) accelerate the primary electrons which provide the extended, non-thermal radio emission seen over ∼150pc scales above and below the plane (the Galactic Centre lobe); and (v) accelerate the primary protons and heavier ions which, advected to very large scales (up to ∼10kpc), generate the recently identified Wilkinson Microwave Anisotropy Probe (WMAP) haze and corresponding Fermi haze/bubbles. Our modelling bounds the average magnetic field amplitude in the inner few degrees of the Galaxy to the range 60 < B/μ G < 40 0 (at 2σ confidence) and shows that even TeV CRs likely do not have time to penetrate into the cores of the region's dense molecular clouds before the wind removes them from the region. This latter finding apparently disfavours scenarios in which CRs - in this starburst-like environment - act to substantially modify the conditions of star formation. We speculate that the wind we identify plays a crucial role in advecting low-energy positrons from the Galactic nucleus into the bulge, thereby explaining the extended morphology of the 511keV line emission. We present extensive appendices reviewing the environmental conditions in the Galactic Centre, deriving the star formation and supernova rates there, and setting out the extensive prior evidence that exists, supporting the notion of a fast outflow from the region.

AB - We consider the high-energy astrophysics of the inner ∼200pc of the Galaxy. Our modelling of this region shows that the supernovae exploding here every few thousand years inject enough power to (i) sustain the steady-state, in situ population of cosmic rays (CRs) required to generate the region's non-thermal radio and TeV γ-ray emission; (ii) drive a powerful wind that advects non-thermal particles out of the inner Galactic Centre; (iii) supply the low-energy CRs whose Coulombic collisions sustain the temperature and ionization rate of the anomalously warm envelope detected throughout the Central Molecular Zone; (iv) accelerate the primary electrons which provide the extended, non-thermal radio emission seen over ∼150pc scales above and below the plane (the Galactic Centre lobe); and (v) accelerate the primary protons and heavier ions which, advected to very large scales (up to ∼10kpc), generate the recently identified Wilkinson Microwave Anisotropy Probe (WMAP) haze and corresponding Fermi haze/bubbles. Our modelling bounds the average magnetic field amplitude in the inner few degrees of the Galaxy to the range 60 < B/μ G < 40 0 (at 2σ confidence) and shows that even TeV CRs likely do not have time to penetrate into the cores of the region's dense molecular clouds before the wind removes them from the region. This latter finding apparently disfavours scenarios in which CRs - in this starburst-like environment - act to substantially modify the conditions of star formation. We speculate that the wind we identify plays a crucial role in advecting low-energy positrons from the Galactic nucleus into the bulge, thereby explaining the extended morphology of the 511keV line emission. We present extensive appendices reviewing the environmental conditions in the Galactic Centre, deriving the star formation and supernova rates there, and setting out the extensive prior evidence that exists, supporting the notion of a fast outflow from the region.

KW - Cosmic rays

KW - Galaxies: star formation

KW - Galaxy: centre

KW - ISM: jets and outflows

KW - ISM: supernova remnants

KW - Radiation mechanisms: non-thermal

UR - http://www.scopus.com/inward/record.url?scp=79955159093&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=79955159093&partnerID=8YFLogxK

U2 - 10.1111/j.1365-2966.2010.18170.x

DO - 10.1111/j.1365-2966.2010.18170.x

M3 - Article

AN - SCOPUS:79955159093

VL - 413

SP - 763

EP - 788

JO - Monthly Notices of the Royal Astronomical Society

JF - Monthly Notices of the Royal Astronomical Society

SN - 0035-8711

IS - 2

ER -