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Related papers: FUV Scattering by Dust in Orion

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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…

Astrophysics of Galaxies · Physics 2017-05-02 Gautam Saikia , P. Shalima , Rupjyoti Gogoi , Amit Pathak

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…

Astrophysics of Galaxies · Physics 2015-06-19 Richard Conn Henry , Jayant Murthy , James Overduin , Joshua Tyler

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)…

Astrophysics of Galaxies · Physics 2019-08-12 M. S. Akshaya , Jayant Murthy , S. Ravichandran , R. C. Henry , James Overduin

The existence of multiple layers in the inner Orion Nebula has been revealed using data from an Atlas of spectra at 2" and 12 km/s resolution. These data were sometimes grouped over Samples of 10"x10"to produce high Signal to Noise spectra…

Astrophysics of Galaxies · Physics 2018-05-02 C. R. O'Dell

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…

Astrophysics of Galaxies · Physics 2015-05-20 N. V. Sujatha , Jayant Murthy , Rahul Suresh , Richard Conn Henry , Luciana Bianchi

I have used Monte Carlo models with multiple scattering to predict the dust scattered light from our Galaxy and have compared the predictions with data in two UV bands from the GALEX spacecraft. I find that 90\% of the scattered light…

Astrophysics of Galaxies · Physics 2016-04-12 Jayant Murthy

We have constructed a far-ultraviolet (FUV) continuum map of the Taurus-Auriga-Perseus complex, one of the largest local associations of dark clouds, by merging the two data sets of GALEX and FIMS, which made observations at similar…

Astrophysics of Galaxies · Physics 2015-06-12 Tae-Ho Lim , Kyoung-Wook Min , Kwang-Il Seon

Ultraviolet observations from low Earth orbit (LEO) have to deal with a foreground comprised of airglow and zodiacal light which depend on the look direction and on the date and time of the observation. We have used all-sky observations…

Instrumentation and Methods for Astrophysics · Physics 2014-03-11 Jayant Murthy

We calculate the scattering of X-rays by interstellar dust, for a dust model that reproduces the observed wavelength-dependent extinction and polarization of starlight. On interstellar sightlines that produce appreciable starlight…

Astrophysics · Physics 2008-11-26 B. T. Draine , Khosrow Allaf-Akbari

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…

Astrophysics of Galaxies · Physics 2020-04-14 Jayant Murthy , R. C. Henry , James Overduin

We present the first observations of diffuse radiation in the far ultraviolet (1000 -- 1150 \AA) from the Large Magellanic Cloud based on observations made with the {\it Far Ultraviolet Spectroscopic Explorer}. The fraction of the total…

Astrophysics of Galaxies · Physics 2015-05-19 Ananta C. Pradhan , Amit Pathak , Jayant Murthy

We have observed intense diffuse radiation in the UV (1400 A - 2600 A) from three fields around M42 in Orion. Intensities of 20000 photons cm-2 s-1 sr-1 A-1 were observed to the east and west of M42 with 8000 photons cm-2 s-1 sr-1 A-1 south…

Astrophysics · Physics 2007-05-23 Jayant Murthy , R. C. Henry , L. J. Paxton , S. D. Price

I explore models of the dust-scattered component of the Cosmic Ultraviolet Background (CUVB) at the North Galactic Pole (NGP) in order to develop a framework for calculating the dust-scattered light as a function of the optical depths. As…

Instrumentation and Methods for Astrophysics · Physics 2025-07-08 Jayant Murthy

Orion's veil consists of several layers of largely neutral gas lying between us and the main ionizing stars of the Orion nebula. It is visible in 21cm H I absorption and in optical and UV absorption lines of H I and other species. Toward…

Astrophysics · Physics 2008-11-26 N. P. Abel , C. L. Brogan , G. J. Ferland , C. R. O'Dell , G. Shaw , T. H. Troland

The optical [N I] doublet near 5200 {\AA} is anomalously strong in a variety of emission-line objects. We compute a detailed photoionization model and use it to show that pumping by far-ultraviolet (FUV) stellar radiation previously posited…

Astrophysics of Galaxies · Physics 2015-06-11 G. J. Ferland , W. J. Henney , C. R. O'Dell , R. L. Porter , P. A. M. van Hoof , R. J. R. Williams

We report on the discovery of a mid-infrared source at a projected distance of only 1200 AU from the O9.5 V star sigma Orionis. The spatially resolved, fan-shaped morphology and the presence of an ionization front, as well as evidence in…

Astrophysics · Physics 2011-05-23 Jacco Th. van Loon , Joana M. Oliveira

GALEX has detected ultraviolet halos extending as far as 5$^{\circ}$ around four bright stars (Murthy et al. (2011)). These halos are produced by scattering of starlight by dust grains in thin foreground clouds that are not physically…

Astrophysics of Galaxies · Physics 2015-06-16 P. Shalima , Jayant Murthy , Ranjan Gupta

A sample of local galaxies for which far infrared and uv fluxes are available is used to estimate the characteristic dust extinction in galaxies and to test whether standard dust properties are plausible. Assuming galaxies can be…

Astrophysics · Physics 2009-11-07 Michael Rowan-Robinson

We present an analysis of the diffuse ultraviolet (UV) background in a low latitude region near the Aquila Rift based on observations made by the Galaxy Evolution Explorer (GALEX). The UV background is at a level of about 2000 ph cm^-2 s^-1…

Astrophysics of Galaxies · Physics 2015-10-14 S. N. Jyothy , Jayant Murthy , Narayanankutty Karuppath , N. V. Sujatha

We discuss the dust attenuation and the star formation rates in the nearby universe obtained from a comparison of far-infrared (IRAS) and ultraviolet (GALEX) observations. The ratio of the dust to UV flux ratio is used to derive the dust…

Astrophysics · Physics 2009-11-10 V. Buat