Related papers: The Diffuse Ultraviolet and Optical Background: St…
We propose a multi-component model for the observed diffuse neutrino flux, including the residual atmospheric backgrounds, a Galactic contribution (such as from cosmic ray interactions with gas), an extra-galactic contribution from pp…
The Galactic gamma-ray flux can be described as the sum of two components: the first is due to the emission from an ensemble of discrete sources, and the second is formed by the photons produced by cosmic rays propagating in interstellar…
We present an analysis of the far-ultraviolet upturn phenomenon (UVX) observed in elliptical galaxies and spiral galaxy bulges. Our premise is that the UV radiation from these systems emanates primarily from extreme horizontal branch (EHB)…
A general theoretical framework is developed for interpreting spectropolarimetric observations of optically thin emission line scattering from small dust particles. Spatially integrated and spatially resolved line profiles of both scattered…
Super- and subradiance are usually described in the framework of Dicke collective states, which is an ``atomic picture'' in which the electromagnetic field only provides an effective interaction between the atoms. Here, we discuss a…
The cosmic background (CB) radiation, encompassing the sum of emission from all sources outside our own Milky Way galaxy across the entire electromagnetic spectrum, is a fundamental phenomenon in observational cosmology. Many experiments…
The upper atmospheres of the planets and their satellites are more directly exposed to sunlight and solar wind particles than the surface or the deeper atmospheric layers. At the altitudes where the associated energy is deposited, the…
The Extragalactic Background Light (EBL) as an integrated light from outside of our Galaxy includes information of the early universe and the Dark Ages. We analyzed the spectral data of the astrophysical diffuse emission obtained with the…
By using the public UV imaging data obtained by the GALEX (Galaxy Ultraviolet Explorer) for nearby galaxies, we have compiled a list of lenticular galaxies possessing ultraviolet rings - starforming regions tightly confined to particular…
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 study the inverse Compton scattering of solar photons by Galactic cosmic-ray electrons. We show that the gamma-ray emission from this process is substantial with the maximum flux in the direction of the Sun; the angular distribution of…
Diffuse and translucent molecular clouds fill a vast majority of the interstellar space in the galactic disk being thus the most typical objects of the Interstellar Medium (ISM). Recent advances in observational techniques of modern optical…
Assuming a spherical symmetry, the extreme UV emitted by a very hot source ionizes low pressure molecular hydrogen making a transparent bubble of H II (Protons and electrons). For an increase of radius, intensity of extreme UV and…
We have discovered ultraviolet halos extending as far as 5{\deg} around four (of six) bright UV stars using data from the GALEX satellite. These halos are due to the scattering of the starlight from nearby thin, foreground dust clouds. We…
Partially overlapping galaxies are used to directly determine the effective absorption in spiral galaxy disks. The non-overlapping parts of the galaxies and symmetry considerations are used to reconstruct, via differential photometry, how…
The Spectroscopy of Plasma Evolution from Astrophysical Radiation (or the Far-ultraviolet Imaging Spectrograph) instruments, flown aboard the STSAT-1 satellite mission, have provided the first large-area spectral mapping of the cosmic far…
A large fraction of the baryonic matter in the Universe is located in filaments in the intergalactic medium. However, the low surface brightness of these filaments has not yet allowed their direct detection except in very special regions in…
Circumgalactic dust grains trace the circulation of mass and metals between star-forming regions and gaseous galactic halos, giving insight into feedback and tidal stripping processes. We perform a search for ultraviolet (UV) reflection…
Diffuse Galactic cirrus, or Diffuse Galactic Light (DGL), can be a prominent component in the background of deep wide-field imaging surveys. The DGL provides unique insights into the physical and radiative properties of dust grains in our…
We summarize the relationship between the free-free emission foreground and Galactic H-alpha emission. H-alpha observations covering nearly the entire celestial sphere are described. These data provide a template to isolate and/or remove…