Results 21 to 30 of about 1,583 (233)

Shedding new light on the Crab with polarized X-rays

Scientific Reports, 2017
Strong magnetic fields, synchrotron emission, and Compton scattering are omnipresent in compact celestial X-ray sources. Emissions in the X-ray energy band are consequently expected to be linearly polarized. X-ray polarimetry provides a unique diagnostic
M. Chauvin, H.-G. Florén, M. Friis, M. Jackson, T. Kamae, J. Kataoka, T. Kawano, M. Kiss, V. Mikhalev, T. Mizuno, N. Ohashi, T. Stana, H. Tajima, H. Takahashi, N. Uchida, M. Pearce   +15 more
doaj   +1 more source

The NIKA polarimeter on science targets: Crab nebula observations at 150 GHz and dual-band polarization images of Orion Molecular Cloud OMC-1 [PDF]

EPJ Web of Conferences, 2020
We present here the polarization system of the NIKA camera and give a summary of the main results obtained and performed studies on Orion and the Crab nebula.
Ritacco A., Adam R., Ade P., André P., Andrianasolo A., Aussel H., Beelen A., Benoît A., Bideaud A., Bourrion O., Calvo M., Catalano A., Comis B., De Petris M., Désert F.-X., Doyle S., Driessen E.F.C., Gomez A., Goupy J., Kéruzoré F., Kramer C., Ladjelate B., Lagache G., Leclercq S., Lestrade J.-F., Macías-Pérez J.F., Mauskopf P., Maury A., Mayet F., Monfardini A., Perotto L., Pisano G., Ponthieu N., Revéret V., Romero C., Roussel H., Ruppin F., Schuster K., Shu S., Sievers A., Tucker C., Zylka R.   +41 more
doaj   +1 more source

On the Nature of the Emission of the Crab Nebula [PDF]

Symposium - International Astronomical Union, 1958
The emission of the Crab Nebula is perhaps connected with the internal motions of the gas. As shown by the observations, the power of the emission sources differs by some hundred times in different points of the amorphous mass (“wisps” and other details).
openaire   +2 more sources

SiO Emission from the Orion Nebula [PDF]

Symposium - International Astronomical Union, 1980
SiO emission in both a strong maser transition in the first excited vibrational state and in a weaker transition in the ground vibrational state both arise from the same small region in the Kleinmann-Low Nebula in Orion. Within the errors, the source position coincides with that of the infrared source IRc2.
John H. Bieging, B. Baud, W. J. Welch, M. C. H. Wright, D. D. Thornton, Richard Plambeck   +5 more
openaire   +2 more sources

Exploring the high abundance discrepancy in the planetary nebula IC 4663

Frontiers in Astronomy and Space Sciences, 2023
This article presents an in-depth analysis of integral field unit spectroscopy performed on the Galactic planetary nebula (PN) IC 4663, with a primary focus on investigating its physical characteristics, chemical composition, and morphological properties.
M. Mohery, A. Ali, Aya A. Khames, S. Snaid, A. Mindil   +4 more
doaj   +1 more source

Emission Nebulae as Radio Sources [PDF]

Australian Journal of Physics, 1956
Attempts have been made to detect 14 bright emission nebulae at a wavelength of 3?5 m using a pencil-beam radio telescope with a beamwidth of 50 min of arc. Of these nebulae, six were probably observed in emission, seven were undetectable, and one, NGC 6357, was observed in absorption; radio isophotes were obtained for NGC 2237 and NGC 3372.
A. G. Little, KV Sheridan, B. Y. Mills
openaire   +2 more sources

Bursts of the Crab Nebula gamma-ray emission at high and ultra-high energies

EPJ Web of Conferences, 2017
Characteristics of the flares of gamma rays detected from the Crab Nebula by the AGILE and Fermi-LAT satellite instruments are compared with those of a gamma ray burst recorded by several air shower arrays on February 23, 1989 and with one recent ...
Lidvansky A.S.
doaj   +2 more sources

Photometric and spectroscopic study of five pre-main sequence stars in the vicinity of NGC 7129 [PDF]

Serbian Astronomical Journal, 2019
We present results from long-term optical photometric and spectroscopic observations of five pre-main sequence stars, located in the vicinity of the bright nebula NGC 7129.
Semkov E.H., Ibryamov S.I., Peneva S.P.
doaj   +1 more source

Modelling the ArH+ emission from the Crab nebula [PDF]

Monthly Notices of the Royal Astronomical Society, 2017
Abstract We have performed combined photoionization and photodissociation region (PDR) modelling of a Crab nebula filament subjected to the synchrotron radiation from the central pulsar wind nebula, and to a high flux of charged particles; a greatly enhanced cosmic-ray ionization rate over the standard interstellar value, ζ0, is required
F. D. Priestley, M. J. Barlow, S. Viti
openaire   +5 more sources

Magnetic Fields in the Horsehead Nebula

The Astronomical Journal, 2023
We present the first polarized dust emission measurements of the Horsehead Nebula, obtained using the POL-2 polarimeter on the Submillimetre Common-User Bolometer Array 2 (SCUBA-2) camera on the James Clerk Maxwell Telescope.
Jihye Hwang, Kate Pattle, Harriet Parsons, Mallory Go, Jongsoo Kim   +4 more
doaj   +1 more source