相关论文: On the Origins of the High-Latitude H-alpha Backgr…

Galactic dust constitutes approximately half of the elements more massive than helium produced in stellar nucleosynthesis. Notwithstanding the formation of dust grains in the dense, cool atmospheres of late-type stars, there still remain…

It has been suggested that high velocity clouds may be distributed throughout the Local Group and are therefore not in general associated with the Milky Way galaxy. With the aim of testing this hypothesis, we have made observations in the…

Near-infrared (IR) diffuse Galactic light (DGL) consists of scattered light and thermal emission from interstellar dust grains illuminated by interstellar radiation field (ISRF). At 1.25 and 2.2um, recent observational study shows that…

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 present a model for the interpretation of the gamma-ray background emission from the Galactic halo, which we attribute to interaction of high-energy cosmic rays with dense molecular clumps. In a wide range of clump parameters we…

A set of diffuse interstellar clouds in the inner Galaxy within a few hundred pc of the Galactic plane has been observed at an angular resolution of ~1 arcmin combining data from the NRAO Green Bank Telescope and the Very Large Array. At…

We combine parallax distances to nearby O stars with parsec-scale resolution three-dimensional dust maps of the local region of the Milky Way (within 1.25 kpc of the Sun) to simulate the transfer of Lyman continuum photons through the…

We present an all sky map of the diffuse Galactic far ultraviolet (1344-1786 Angstroms) background using GALEX data, covering 65% of the sky with 11.79 arcmin square pixels. We investigate the dependence of the background on Galactic…

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…

The diffuse gamma-ray background radiation (GBR) at high Galactic latitudes could be dominated by inverse Compton scattering (ICS) of cosmic ray (CR) electrons on the cosmic microwave background radiation (CBR) and on starlight (SL) in an…

Optical emission lines have now been detected from about 20 high velocity clouds. These emission lines -- primarily H-alpha, secondarily [N II] and [S II] -- are very faint and diffuse, spread over the surfaces of the clouds. We compile…

The inverse Compton scattering of interstellar photons off cosmic-ray electrons seems to play a more important role in the generation of diffuse emission from the Galaxy than thought before. The background radiation field of the Galaxy is…

The properties of high latitude dust are of great interest to extragalactic astronomers and cosmologists. It is proposed here that essentially all high Galactic latitude interstellar dust is at a typical temperature of about 20~K (i.e. it…

In the powerful, high redshift radio galaxies, it is believed that the dominant source of ionization for the interstellar gas is the hard radiation field associated with the active nucleus. The photon source is generally external to the…

Galactic cirrus emission at far-infrared wavelengths affects many extragalactic observations. Separating this emission from that associated with extragalactic objects is both important and difficult. In this paper we discuss a particular…

We explore the possibility that the diffuse gamma-ray background radiation (GBR) at high galactic latitudes could be dominated by inverse Compton scattering of cosmic ray (CR) electrons on the cosmic microwave background radiation and on…

The nebular recombination line H$\alpha$ is widely used as a star-formation rate (SFR) indicator in the local and high-redshift Universe. We present a detailed H$\alpha$ radiative transfer study of high-resolution isolated Milky-Way and…

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…

The H-alpha luminosity density of galaxies is used to calculate the local diffuse radiation field at the Lyman limit as resulting from star formation in the universe. The fraction of Lyman continuum radiation leaking out from galaxies…

We present constraints on the density of halo dark matter candidates within the solar circle based on the anisotropy in the high energy gamma-ray background. The known galactic components of the gamma-ray background, in particular the…