First gamma-ray pulsar found outside Milky Way is the most energetic yet

Physics Today ◽  
2015 ◽  
Keyword(s):  
Milky Way ◽  
Gamma Ray

scholarly journals The characterization of the gamma-ray signal from the central Milky Way: A case for annihilating dark matter

2016 ◽  
Vol 12 ◽  
pp. 1-23 ◽  
Author(s):  
Tansu Daylan ◽  
Douglas P. Finkbeiner ◽  
Dan Hooper ◽  
Tim Linden ◽  
Stephen K.N. Portillo ◽  
...  
Keyword(s):  
Dark Matter ◽  
Milky Way ◽  
Gamma Ray

scholarly journals LIGHT SUPERCONDUCTING STRINGS IN THE GALAXY

2007 ◽  
Vol 16 (12b) ◽  
pp. 2399-2405 ◽  
Author(s):  
FRANCESC FERRER ◽  
TANMAY VACHASPATI
Keyword(s):  
Magnetic Field ◽  
Spatial Distribution ◽  
Particle Physics ◽  
Milky Way ◽  
Gamma Ray ◽  
Galactic Center ◽  
Line Emission ◽  
Galactic Magnetic Field ◽  
The Galaxy ◽  
Intense Source

Observations of the Milky Way by the SPI/INTEGRAL satellite have confirmed the presence of a strong 511 keV gamma ray line emission from the bulge, which requires an intense source of positrons in the galactic center. These observations are hard to account for by conventional astrophysical scenarios, whereas other proposals, such as light DM, face stringent constraints from the diffuse gamma ray background. Here we suggest that light superconducting strings could be the source of the observed 511 keV emission. The associated particle physics, at the ~ 1 TeV scale, is within the reach of planned accelerator experiments, while the distinguishing spatial distribution, proportional to the galactic magnetic field, could be mapped by SPI or by future, more sensitive satellite missions.

scholarly journals On the delay times of merging double neutron stars

2020 ◽  
Vol 500 (2) ◽  
pp. 1755-1771
Author(s):  
Laura Greggio ◽  
Paolo Simonetti ◽  
Francesca Matteucci
Keyword(s):  
Neutron Stars ◽  
Binary Systems ◽  
Milky Way ◽  
Gamma Ray ◽  
Chemical Properties ◽  
Redshift Distribution ◽  
Strong Constraint ◽  
Delay Times ◽  
Best Fitting ◽  
Short Grbs

ABSTRACT The merging rate of double neutron stars (DNS) has a great impact on many astrophysical issues, including the interpretation of gravitational waves signals, of the short gamma-ray bursts (GRBs), and of the chemical properties of stars in galaxies. Such rate depends on the distribution of the delay times (DDT) of the merging events. In this paper, we derive a theoretical DDT of merging DNS following from the characteristics of the clock controlling their evolution. We show that the shape of the DDT is governed by a few key parameters, primarily the lower limit and the slope of the distribution of the separation of the DNS systems at birth. With a parametric approach, we investigate on the observational constraints on the DDT from the cosmic rate of short GRBs and the europium-to-iron ratio in Milky Way stars, taken as tracer of the products of the explosion. We find that the local rate of DNS merging requires that $\sim \! 1 {{\ \rm per\ cent}}$ of neutron stars progenitors live in binary systems which end their evolution as merging DNS within a Hubble time. The redshift distribution of short GRBs does not yet provide a strong constraint on the shape of the DDT, although the best-fitting models have a shallow DDT. The chemical pattern in Milky Way stars requires an additional source of europium besides the products from merging DNS, which weakens the related requirement on the DDT. At present both constraints can be matched with the same DDT for merging DNS.

scholarly journals Analysis of the very inner Milky Way dark matter distribution and gamma-ray signals

2016 ◽  
Vol 94 (12) ◽  
Author(s):  
V. Gammaldi ◽  
V. Avila-Reese ◽  
O. Valenzuela ◽  
A. X. Gonzalez-Morales
Keyword(s):  
Dark Matter ◽  
Milky Way ◽  
Gamma Ray ◽  
Matter Distribution ◽  
Dark Matter Distribution

scholarly journals Multiwavelength Milky Way: An Educational Poster

1998 ◽  
Vol 179 ◽  
pp. 237-237 ◽  
Author(s):  
D. Leisawitz ◽  
S.W. Digel ◽  
S. Geitz
Keyword(s):  
Milky Way ◽  
Gamma Ray ◽  
Line Emission ◽  
Electromagnetic Spectrum ◽  
Data Sets ◽  
X Ray ◽  
Nasa Goddard Space ◽  
Broadband Emission ◽  
The Galaxy ◽  
Effective Use

The Astrophysics Data Facility at NASA Goddard Space Flight Center supports the processing, management, and dissemination of data obtained by past, current, and future NASA and international astrophysics missions, and promotes the effective use of those data by the astrophysics community, educators, and the public. Our Multiwavelength Milky Way poster was printed for broad distribution. It depicts the Galaxy at radio, infrared, optical, X-ray, and gamma-ray wavelengths. In particular, the poster contains images of the Galactic 21-cm and CO (J = 1 → 0) line emission, and IRAS 12, 60, and 100 μm, COBE/DIRBE 1.25, 2.2, and 3.5 μm, Digitized Sky Survey optical wavelength, ROSAT/PSPC 0.25, 0.75, and 1.5 keV X-ray, and CGRO/EGRET E > 100 MeV gamma ray broadband emission. All of the data sets are publicly available. Captions describe the Milky Way and what can be learned about the Galaxy from measurements made in each segment of the electromagnetic spectrum. The poster is intended to be an educational tool, one that will stimulate heightened awareness by laypersons of NASA's contribution to modern astronomy.Through an interface available on the World Wide Web at http://adf.gsfc.nasa.gov/adf/adf.html one may view the images that appear on the poster, read the poster captions, and locate the archived data and references.

scholarly journals Using gamma ray monitoring to avoid missing the next Milky Way Type Ia supernova

2019 ◽  
Vol 486 (2) ◽  
pp. 2910-2918 ◽  
Author(s):  
Xilu Wang (王夕露) ◽  
Brian D Fields ◽  
Amy Yarleen Lien (連雅琳)
Keyword(s):  
Gamma Rays ◽  
Milky Way ◽  
Gamma Ray ◽  
Galactic Plane ◽  
Early Warning Systems ◽  
Light Curves ◽  
X Rays ◽  
Warning Systems ◽  
Type Ia Supernova ◽  
Type Ia

Abstract A Milky Way Type Ia supernova (SNIa) could be unidentified or even initially unnoticed, being dim in radio, X-rays, and neutrinos, and suffering large optical/IR extinction in the Galactic plane. But SNIa emit nuclear gamma-ray lines from 56Ni → 56Co → 56Fe radioactive decays. These lines fall within the Fermi/GBM energy range, and the 56Ni 158 keV line is detectable by Swift/BAT. Both instruments frequently monitor the Galactic plane, which is transparent to gamma rays. Thus GBM and BAT are ideal Galactic SNIa early warning systems. We simulate SNIa MeV light curves and spectra to show that GBM and BAT could confirm a Galactic SNIa explosion, followed by Swift localization and observation in X-rays and UVOIR band. The time of detection depends sensitively on the 56Ni distribution, and can be as early as a few days if ${\gtrsim } 10{{\ \rm per\ cent}}$ of the 56Ni is present in the surface as suggested by SN2014J gamma data.

scholarly journals GAMMA-400 experiment: perspectives of observation of the discrete astrophysical gamma-ray sources in the Milky Way disk

2019 ◽  
Vol 1181 ◽  
pp. 012073
Author(s):  
A V Bakaldin ◽  
A M Galper ◽  
A A Leonov ◽  
S I Suchkov ◽  
N P Topchiev
Keyword(s):  
Milky Way ◽  
Gamma Ray

scholarly journals The consequence of a new ISRF model of the Milky Way on predictions for diffuse gamma-ray emission

2019 ◽  
Vol 107 ◽  
pp. 1-14 ◽  
Author(s):  
F. Niederwanger ◽  
O. Reimer ◽  
R. Kissmann ◽  
A.W. Strong ◽  
C.C. Popescu ◽  
...  
Keyword(s):  
Milky Way ◽  
Gamma Ray ◽  
Gamma Ray Emission

scholarly journals The effects of cosmic rays on the formation of Milky Way-mass galaxies in a cosmological context

2020 ◽  
Vol 497 (2) ◽  
pp. 1712-1737 ◽  
Author(s):  
Tobias Buck ◽  
Christoph Pfrommer ◽  
Rüdiger Pakmor ◽  
Robert J J Grand ◽  
Volker Springel
Keyword(s):  
Cosmic Rays ◽  
Milky Way ◽  
Gamma Ray ◽  
Transport Model ◽  
Formation Rate ◽  
Wave Model ◽  
Alfven Wave ◽  
Small Scale ◽  
Density Peaks ◽  
The Impact

ABSTRACT We investigate the impact of cosmic rays (CRs) and different modes of CR transport on the properties of Milky Way-mass galaxies in cosmological magnetohydrodynamical simulations in the context of the AURIGA project. We systematically study how advection, anisotropic diffusion, and additional Alfvén-wave cooling affect the galactic disc and the circumgalactic medium (CGM). Global properties such as stellar mass and star formation rate vary little between simulations with and without various CR transport physics, whereas structural properties such as disc sizes, CGM densities, or temperatures can be strongly affected. In our simulations, CRs affect the accretion of gas on to galaxies by modifying the CGM flow structure. This alters the angular momentum distribution that manifests itself as a difference in stellar and gaseous disc size. The strength of this effect depends on the CR transport model: CR advection results in the most compact discs while the Alfvén-wave model resembles more the AURIGA model. The advection and diffusion models exhibit large (r ∼ 50 kpc) CR pressure-dominated gas haloes causing a smoother and partly cooler CGM. The additional CR pressure smoothes small-scale density peaks and compensates for the missing thermal pressure support at lower CGM temperatures. In contrast, the Alfvén-wave model is only CR pressure dominated at the disc–halo interface and only in this model the gamma-ray emission from hadronic interactions agrees with observations. In contrast to previous findings, we conclude that details of CR transport are critical for accurately predicting the impact of CR feedback on galaxy formation.

INTEGRAL results on the electron-positron annihilation radiation and X-ray & Gamma-ray diffuse emission of the Milky Way

2020 ◽  
Vol 90 ◽  
pp. 101548 ◽  
Author(s):  
Eugene Churazov ◽  
Laurent Bouchet ◽  
Pierre Jean ◽  
Elisabeth Jourdain ◽  
Jürgen Knödlseder ◽  
...  
Keyword(s):  
Positron Annihilation ◽  
Milky Way ◽  
Gamma Ray ◽  
Annihilation Radiation ◽  
Diffuse Emission ◽  
X Ray ◽  
Electron Positron Annihilation ◽  
Electron Positron
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