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Galactic astronomy is the study of the Milky Way galaxy and all its contents. This is in contrast to extragalactic astronomy, which is the study of everything outside our galaxy, including all other galaxies.

1644 Results for the subject "Galactic Astronomy":

Evidence the Galactic contribution to the IceCube astrophysical neutrino flux

AbstractWe show that the Galactic latitude distribution of IceCube astrophysical neutrino events with energies above 100 TeV is inconsistent with the isotropic model of the astrophysical neutrino flux. Namely, the Galactic latitude distribution of the events shows an excess at low latitudes |b| < 10° and a deficit at high Galactic latitude |b| ≳50°. We use Monte–Carlo simulations to show that the inconsistency of the isotropic signal model with the data is at ≳3σ level, after the account of trial factors related to the choice of the low-energy threshold and Galactic latitude binning in our analysis.

Andrii Neronov Publication date: 2016/02/15
Neutrinos from extra-large Hadron Collider in the Milky Way

AbstractNeutrino telescope IceCube has recently discovered astrophysical neutrinos with energies in the TeV–PeV range. We use the data of Fermi γ-ray telescope to demonstrate that the neutrino signal has significant contribution from the Milky Way Galaxy. Matching the γ-ray and neutrino spectra we find that TeV–PeV Galactic cosmic rays form a powerlaw spectrum with the slope p ≃ 2.45. This spectral slope is consistent with the average cosmic ray spectrum in the disks of the Milky Way and Large Magellanic Cloud galaxies. It is also consistent with the theoretical model of cosmic ray injection by diffusive shock acceleration followed by escape through the Galactic magnetic field with Kolmogorov turbulence. The locally observed TeV–PeV cosmic ray proton spectrum is softer than the average Galactic cosmic ray spectrum. This could be readily explained by variability of injection of cosmic rays in the local interstellar medium over the past 107 year and discreetness of the cosmic r Read more...

Andrii Neronov Publication date: 2016/01/01
Simulation on gamma ray astronomy research with LHAASO-KM2A

AbstractLHAASO (Large High Altitude Air Shower Observatory) is a large project to research on high energy gamma ray astronomy and cosmic ray physics. KM2A (one KM2 Array), one main part of the LHAASO project, using a 1 km2 array composed of electron detectors (ED) and muon detectors (MD), focuses on gamma ray astronomy above 30 TeV and cosmic ray physics in the “knee” region. Accurate measurement of gamma ray energy spectra above 30 TeV is crucial to identify the sources as the galactic cosmic ray accelerators. Monte Carlo simulation indicates that cosmic gamma rays can be distinguished from cosmic nuclei background by using muon content in extensive air showers (EAS). With the sensitivity of about 1% of the integral flux of Crab Nebula, the high duty cycle of at least 90% and the full sky survey, the KM2A array would be very useful in discovering the galactic gamma ray sources and identifying the cosmic ray sources with gamma-ray emission. A detailed simulation is carried out f Read more...

Shuwang Cui Publication date: 2014/02/01
The SAX mission

AbstractSAX denotes the X-Ray Astronomy Satellite selected by the Italian National Space Plan for inclusion in the Science Programme. The purpose of SAX is to perform spectroscopic, spectral and time variability studies of celestial X-Ray sources in the energy band from 1 to 200 KeV. It is intended to continue and expand upon previous observations of such sources. The instrumentation consists of four X-Ray imaging concentrators sensitive from 1 to 10 KeV (one of them extending down to 0.1 KeV), one Gas Scintillation Proportional Counter sensitive from 3 to 120 KeV, a Sodium Iodide Scintillator Crystal in Phoswich configuration operating from 15 KeV to 200 KeV; these detectors are coaligned to a common pointing axis. Three Wide Field Cameras (2–30 KeV) with axis at 90° to that of the narrow field instruments complete the payload.The Satellite launch is foreseen for 1988, in a low altitude (500 Km), low inclination (12°) orbit.The SAX scientific programme is carried out by a Consorti Read more...

L. Scarsi Publication date: 1984/01/01
Low and medium energy gamma-ray astronomy — present status and future aspects

AbstractDuring the last few years quite some progress has been achieved in the field of low and medium energy gamma-ray astronomy below about 30 MeV. Gamma rays from the galactic center and anti-center region have been detected, which require a high interstellar electron flux in the 100 MeV range, if they are predominantly diffuse in nature. Though the Crab pulsar and its nebula are still the only galactic gamma-ray sources which definitely have been detected, some recently determined upper limits to the gamma-ray fluxes of other radio pulsars are close to the theoretically expected values. Active galaxies seem to have a maximum of luminosity in the range between several 100 keV and a few MeV and, therefore, are of special interest. First observational results have been reported on the Seyfert galaxies NGC 4151 and MCG 8-11-11, and the radio galaxy CenA. The nature of the diffuse cosmic gamma-ray component at low gamma-ray energies is not yet solved. Unresolved active galaxies are good Read more...

V. Schönfelder Publication date: 1983/01/01
Status and future of high energy diffuse gamma-ray astronomy

AbstractThere are two distinctly different high energy diffuse γ-ray components, one well correlated with broad galactic features and the other apparently isotropic and presumably extragalactic. The observed diffuse galactic high energy γ-radiation is generally thought to be produced in interactions between the cosmic rays and the interstellar matter and photons. It should then ultimately be possible to obtain from the diffuse galactic emission a detailed picture of the galactic cosmic-ray distribution, a high contrast view of the general structure of the galaxy, and further insight into molecular clouds. Two of the candidates for the explanation of the extragalactic diffuse radiation are the sum of emission from active galaxies and matter-antimatter annihilation. A major advancement in the study of the properties of both galactic and extragalactic γ radiation should occur over the next decade.

C.E. Fichtel Publication date: 1983/01/01
Very high energy gamma-ray astronomy and the origin of cosmic rays

The paper highlights the status and motivations of very high energy (E ≥ 100 GeV) γ-ray astronomy in the era of the Compton GRO. I discuss the potential of future ground-based γ-ray observations with emphasis on objectives connected with the general problem of the origin of galactic cosmic rays.

F.A. Aharonian Publication date: 1995/02/01
Gamma ray astronomy and the origin of cosmic rays

A brief survey is made of the rôle of Gamma Ray Astronomy in elucidating the origin of cosmic rays. Topics considered include gamma rays from the Magellanic Clouds, the radial gradient of cosmic rays in the Galaxy, evidence for SNR acceleration and the presence of a Giant Galactic Halo.

A.W. Wolfendale Publication date: 1998/01/01
Recent Results of the ANTARES Neutrino Telescope

AbstractThe discovery of cosmic neutrinos of astrophysical origin by IceCube has started a new chapter in the field of Neutrino Astronomy. Noticeably, a small accumulation of events in the region near the Galactic Centre has been observed: a telescope in the Mediterranean Sea constitutes a great opportunity for the physics quest, since it offers a perfect complementarity to IceCube and, in particular, a better visibility of the Galactic Centre. ANTARES (Astronomy with a Neutrino Telescope and Abyss Environmental RESearch) is the first operational Cherenkov neutrino telescope in the Mediterranean Sea and the largest neutrino detector in the Northern hemisphere, covering an area of about 0.1 km2; located 40 km offshore Toulon, France, at a depth of 2475 m, it has been completed in June 2008 and it is currently taking data. It consists of a tri-dimensional array of 885 photo-multipliers tubes (PMTs), distributed in 12 lines. ANTARES has recently performed a search for an excess of high en Read more...

Giulia De Bonis Publication date: 2016/04/01
IAC-11.A7.2.1: Gamma-ray astronomy technology needs☆

AbstractIn recent decades γ-ray observations have become a valuable tool for studying the universe. Progress made in diverse areas such as gamma-ray bursts (GRBs), nucleosynthesis, and active galactic nuclei (AGNs) has complemented and enriched our astrophysical understanding in many ways. We present an overview of current and future planned space γ-ray missions and discuss technology needs for the next generation of space γ-ray instruments.

N. Gehrels Publication date: 2012/12/01
U.V. astronomy with balloons

AbstractBalloon platforms are becoming more and more reliable as carriers of infrared and UV equipment. The balloon environment offers conditions of lower emissivity and higher transparency of the atmosphere. Precise photometric and spectroscopic measurements can be made in all spectral interval exceeding 1950 Å. Stabilized and unexpensive gondola are now available. Thus, high and low resolution spectra can be obtained for numerous stars. Accurate UV-multiband photometry and spectrophotometry are possible for stars members of large galactic clusters. A stabilized astronomical gondola was carrying a Schmidt photographic camera with UV microchannel plate image converter-intensifier. Systematic surveys of the galactic plane and the galactic poles are in progress. The quality of the UV image is good enough to allow a fine morphological analysis of the large galaxies, to detect a large number of nuclei of galaxies and nebulosities.

M. Golay Publication date: 1981/01/01
Astro-philately; Not so much a hobby, more a way of life

AbstractThe title “Vistas in Astronomy” implies that editorial policy is directed to the broad view of Astronomy. The varied papers in each volume offer a prospect of where Astronomy is going and, sometimes, where it has been. Yet there may still be other frontiers to explore — in the world of the arts.On the premise that the postage stamp may be regarded as an art form, this paper attempts to demonstrate the pleasure to be derived from collecting stamps printed with designs relating to Astronomy. Some readers may be surprised to discover just how many aspects of Astronomy have been depicted on stamps. Again, the non-philatelist may not be aware of the additional items which can be included in a collection of this kind, nor of the importance of postal markings.

Margaret I. Morris Publication date: 1988/01/01
Advances in Solar and Cosmic X-Ray Astronomy: A Survey of Experimental Techniques and Observational Results

Publisher SummaryThis chapter discusses the advances in solar and cosmic X–ray astronomy. Discrete sources of X-ray emission in the corona consist of very hot plasmas confined by magnetic fields, and X-ray bursts seem to be related to instabilities in these fields. Solar X-ray observations touch on several problems associated with plasma confinement as encountered in controlled nuclear fusion. Solar X-radiation gives information about plasmas under conditions presently unobtainable in the laboratory. X-ray bursts are emitted by the hottest or most energetic regions within solar flares, so they may be the key to understanding these complex phenomena. The development of the V-2 rocket permitted man to begin explorations of X-rays from celestial objects and gave birth to the youngest branch of an ancient science. The greatest advancement in cosmic X-ray astronomy has been achieved with the first Small Astronomy Satellite instrumentation carried on board. This satellite had revealed the Read more...

RICHARD B. HOOVER Publication date: 1972/01/01
Gamma-ray constraints on the Galactic halo☆

AbstractSome findings from recent COS-B analyses of the diffuse Galactic γ-ray emission are briefly summarized, with emphasis on their impact for our understanding of the Galactic cosmic-ray halo.

J.B.G.M. Bloemen Publication date: 1990/01/01
The MAGIC telescope project for gamma ray astronomy in the 15 to 300 GeV energy range

In gamma ray astronomy the energy range between 15 and 300 GeV is up to now inaccessible for both satellite borne γ detectors and ground based air Cerenkov telescopes. It is expected that in this energy range the universe is highly transparent and sources such as active galactic nuclei at red shifts of up to ≈2.8 can be observed. The detection of gamma ray bursts would allow one to place a limit on their distance. A short description of a project to build a new, high sensitivity, 17 mØ, air Cerenkov telescope, dubbed the MAGIC telescope, and an overview of its physics potential will be given. The telescope is based upon a 17 mØ decommissioned solar concentrator.

E. Lorenz Publication date: 1996/05/01
On the galactic number of a hypercube

AbstractA galaxy is a union of vertex disjoint stars. The galactic number of a graph is the minimum number of galaxies which partition the edge set. The galactic number of complete graphs is determined. This result is used to give bounds on the galactic number of binary cube graphs. The problem of determining the galactic number of a graph is shown to be NP-complete.

Michael Fellows Publication date: 1988/01/01
Space elevator maturing into a Galactic Harbour

Highlights•3 modern Space Elevator Architectures merged into vision of Galactic Harbour.•Galactic Harbour is a new term for Space Elevator infrastructures.•Galactic Harbour Unifies Transportation and Business Enterprises.

Peter Swan Publication date: 2018/11/01
The first soft gamma-ray image of the Galactic Centre with arc-min accuracy

AbstractPreliminary results from the SIGMA telescope observations of the Galactic Centre in the energy range of 35 keV - 1.3 MeV are presented and discussed. The telescope makes use of the coded aperture imaging technique. Our images from 35 to 300 keV reveal a strong source identified without any doubt with 1E 1740.7–2942, i. e. more than 45 arcmin away from the Galactic Nucleus. If this source is at the distance of the Galactic Centre, it is one of the most luminous objects in the galaxy at these energies.

B. Cordier Publication date: 1991/01/01
Magnetic fields in the galactic Universe, as observed in supershells, galaxies, intergalactic and cosmic realms

AbstractHere I present a survey of magnetic fields in large objects, from the interstellar supershells (10 pc) up to the edge of the Universe (near a redshift z of 10), with an emphasis on discoveries made in the last decade, be they through particle astronomy or electromagnetic astronomy.For each type of object, the basic observational properties are summarized, and the best theoretical scenario which accounts for the large body of observations is discussed.The strength of these large-scale fields can vary from mGauss to μGauss. Magnetism acts as a tracer of the dynamical histories of cosmological and intracluster events, it guides the motion of the interstellar ionised gas, and it aligns the charged dust particles.

Jacques P. Vallée Publication date: 2011/05/01
A satellite swarm for radio astronomy

Highlights•Operational orbits of a satellite swarm for radio astronomy are analyzed.•Lunar orbits are presented as a favorable location for radio-observing satellites.•Methods for optimizing initial swarm configuration for uvw-coverage are presented.•Swarm orbital motion is shown to be well suited for radio astronomy.

E. Dekens Publication date: 2014/09/01
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