Related papers: The Far Ultraviolet Background
The diffuse cosmic background radiation in the GALEX far ultraviolet (FUV, 1300 \AA\ - 1700 \AA) is deduced to originate only partially in the dust-scattered radiation of FUV-emitting stars: the source of a substantial fraction of the FUV…
We have used data from the Galaxy Evolution Explorer to study the different components of the diffuse ultraviolet background in the region between the Galactic latitudes 70-80 degree. We find an offset at zero dust column density (E(B - V)…
The ultraviolet and optical background forms a baseline for any observation of the sky. It includes emission lines and scattered light from the atmosphere; resonant scattering from the Lyman lines of interplanetary hydrogen and the…
"Diffuse" gamma rays consist of several components: truly diffuse emission from the interstellar medium, the extragalactic background, whose origin is not firmly established yet, and the contribution from unresolved and faint Galactic point…
We have used GALEX observations of the North and South Galactic poles to study the diffuse ultraviolet background at locations where the Galactic light is expected to be at a minimum. We find offsets of 230 -- 290 photon units in the FUV…
The universe is filled with a diffuse and isotropic extragalactic background of gamma-ray radiation, containing roughly equal energy flux per decade in photon energy between 3 MeV-100 GeV. The origin of this background is one of the…
We draw attention to observational evidence indicating that a substantial fraction of the well-known cosmic celestial diffuse ultraviolet background radiation field is actually due not to dust-scattered starlight, but rather---considering…
We compare the diffuse H$\alpha$ map of our Galaxy with the FUV (1370-1710\AA) continuum map. The H$\alpha$ intensity correlates well with the FUV intensity. The H$\alpha$/FUV intensity ratio increases in general with the H$\alpha$…
Most low-mass stars form in stellar clusters that also contain massive stars, which are sources of far-ultraviolet (FUV) radiation. Theoretical models predict that this FUV radiation produces photo-dissociation regions (PDRs) on the…
Radiation in the extreme ultraviolet (EUV) and soft X-ray holds clues to the location of the missing baryons, the energetics in stellar feedback processes, and the cosmic enrichment history. Additionally, EUV and soft X-ray photons help…
The gamma-ray background is still a subject under great debate. All phenomena in the universe emitting gamma-rays can contribute directly as diffuse emission or as an isotropic component from unresolved point sources. The question of the…
I report on progress in my ongoing work with Professor Jayant Murthy concerning the origin and nature of the diffuse ultraviolet background radiation over the sky. We have obtained and are reducing a vast trove of Voyager ultraviolet…
Far-ultraviolet radiation is a ubiquitous, if unanticipated, phenomenon in elliptical galaxies and early-type spiral bulges. It is the most variable photometric feature associated with old stellar populations. Recent observational and…
Recent availability of high quality infrared (IR) data for diffuse regions in the Galaxy and external galaxies have added to our understanding of interstellar dust. A comparison of ultraviolet (UV) and IR observations may be used to…
We have studied small scale (2 arcmin) spatial variation of the diffuse UV radiation using a set of 11 GALEX deep observations in the constellation of Draco. We find a good correlation between the observed UV background and the IR 100…
We present the general properties of the far-ultraviolet (FUV; 1370-1720A) continuum background over most of the sky, obtained with the Spectroscopy of Plasma Evolution from Astrophysical Radiation instrument (SPEAR, also known as FIMS),…
Far Ultraviolet radiation has been recognized as the main source of heating of the neutral interstellar gas, and, as a consequence, it determines whether the thermal balance of the neutral gas results in cold ($T\sim 50 - 100 K$) clouds…
The origin of the X-ray emission from the central region of the Galaxy has remained a mystery, despite extensive study over the past two decades. A fundamental question is the relative contribution of the point-source and diffuse components…
Far-Ultraviolet (FUV) radiation greatly exceeds ultraviolet, supernovae and winds in the energy budget of young star clusters but is poorly modeled in galaxy simulations. We present results of the first isolated galaxy disk simulations to…
We have used Voyager and Galex observations to map the diffuse Galactic light near the Galactic equator. We find that most of the observations are relatively faint with surface brightnesses of less than 5,000 photon units. This is important…