Results 1 to 10 of about 1,250,237 (300)

Detection of an H$\alpha$ Emission Line on a Quasar, RX J1759.4$+$6638, at Z = 4.3 with AKARI [PDF]

Publications of the Astronomical Society of Japan, 2007
We report on the detection of an H$\alpha$ emission line in the low-resolution spectrum of a quasar, RX J1759.4$+$6638, at a redshift of 4.3 with the Infrared Camera (IRC) onboard AKARI. This is the first spectroscopic detection of an H$\alpha$ emission line in a quasar beyond $z =$ 4. The overall spectral energy distribution (SED) of RX J1759.4$+$6638
Oyabu, Shinki, Wada, Takehiko, Ohyama, Youichi, Matsuhara, Hideo, Takagi, Toshinobu, Nakagawa, Takao, Onaka, Takashi, Fujishiro, Naofumi, Ishihara, Daisuke, Ita, Yoshifusa, Kataza, Hirokazu, Kim, Woojung, Matsumoto, Toshio, Murakami, Hiroshi, Sakon, Itsuki, Tanabe, Toshihiko, Uemizu, Kazunori, Ueno, Munetaka, Usui, Fumihiko, Watarai, Hidenori, Haze, Kanae   +20 more
openaire   +2 more sources

Doppler-shift oscillations in the H i Lyαcoronal emission line: spectroscopic signature of propagating kink waves? [PDF]

Astronomy & Astrophysics, 2014
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Mancuso, S., Raymond, J. C.
openaire   +1 more source

Behaviour of Hα and H Ca II Emission Lines in a Prominence Before and During its Dynamic “Disparition Brusque” [PDF]

International Astronomical Union Colloquium, 1998
AbstractHα and H Ca II emission lines in a limb quiescent prominence (QP) undergoing destabilization are studied. The temperature, line-of-sight velocity and micro-turbulence are obtained in one of the prominence legs, just before and during the prominence activation.
M.S. Madjarska, V.N. Dermendjiev, Z. Mouradian, P. Kotrč   +3 more
openaire   +1 more source

H Emission-Line Stars in Molecular Clouds. I. The NGC 2264 Region

The Astronomical Journal, 2004
We present a deep survey of H? emission-line stars in the NGC 2264 region using wide-field objective prism films. We find 357 H? emission-line stars, of which 113 were previously detected, within an area of 3? ? 3? centered on the Cone Nebula, with a majority of stars being concentrated in a dense cluster at the center of the region. We present a large-
Bo Reipurth, Bertil Pettersson, Tina Armond, John Bally, Luiz Paulo R. Vaz   +4 more
openaire   +1 more source

Visibility of old supernova remnants in H i 21-cm emission line [PDF]

Monthly Notices of the Royal Astronomical Society, 2004
We estimate the number of old, radiative supernova remnants (SNRs) detectable in HI 21-cm emission line in the Galaxy. According to our result, the contamination due to the Galactic background HI emission limits the number of visible SNRs to 270, or 9% of the total HI SNRs. The telescope sensitivity further limits the number. We compare the result with
Koo, Bon-Chul, Kang, Ji-hyun
openaire   +2 more sources

Deep H i Mapping of Stephan’s Quintet and Its Neighborhood

The Astrophysical Journal, 2023
We carried out deep mapping observations of the atomic hydrogen (H i ) 21 cm line emission in a field centered on the famous galaxy group Stephan's Quintet (SQ), using the Five-hundred-meter Aperture Spherical Telescope (FAST) equipped with a 19-beam ...
Cheng Cheng, Cong Kevin Xu, P. N. Appleton, P.-A. Duc, N.-Y. Tang, Y.-S. Dai, J.-S. Huang, U. Lisenfeld, F. Renaud, Chuan He, Hai-Cheng Feng   +10 more
doaj   +1 more source

Hαemission line spectroscopy in NGC 330

Astronomy & Astrophysics, 2001
We perform an observational test on global oscillations in Be star circumstellar disks in the metal deficient environment of the SMC. According to the hybrid model of disk oscillations early-type Be stars require an optically thin line force to establish a density wave.
Hummel, W., Gassler, W., Muschielok, B., Schink, H., Nicklas, H., Conti, G., Mattaini, E., Keller, S., Mantel, K. H., Appenzeller, I., Rupprecht, G., Seifert, W., Stahl, O., Tarantik, K.   +13 more
openaire   +2 more sources

The HST Sample of Radio-Loud Quasars: Emission Lines from Lyα to Hβ [PDF]

International Astronomical Union Colloquium, 1997
We have obtained HST and ground-based spectrophotometry of a sample of ~61 radio-loud quasars from shortward of Lyα to longward of Hβ. The aim was to investigate the dependence of quasar properties on orientation of the central engine axis to the observer’s line of sight.
Beverley J. Wills, M.S. Brotherton, D. Wills, K.L. Thompson, J. A. Baldwin, R. F. Carswell, I.W.A. Browne, H. Netzer, P.J. Francis   +8 more
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Spectroscopic variability of two Oe stars [PDF]

, 2015
The Oe stars HD45314 and HD60848 have recently been found to exhibit very different X-ray properties: whilst HD60848 has an X-ray spectrum and emission level typical of most OB stars, HD45314 features a much harder and brighter X-ray emission, making it ...
Alves, F., Arnold, W., Bergmann, T., Carreira, L. F. Gouveia, Dias, F. Marques, Eversberg, T., Fahed, R., Fernando, A., Gallego, J. Sanchez, Gonzalez-Perez, J. N., Hempelmann, A., Hunger, T., Knapen, J. H., Leadbeater, R., Mittag, M., Moffat, A. F. J., Morel, T., Naze, Y., Rauw, G., Reinecke, N., Ribeiro, J., Romeo, N., Santos, E. M. Dos, Schanne, L., Schmitt, J. H. M. M., Schroeder, K. -P., Stahl, O., Stober, Ba., Stober, Be., Viegas, N. G. Correia, Vollmann, K.   +30 more
core   +1 more source

WALLABY Pilot Survey: H i in the Host Galaxy of a Fast Radio Burst

The Astrophysical Journal, 2023
We report on the commensal ASKAP detection of a fast radio burst (FRB), FRB 20211127I, and the detection of neutral hydrogen (H i ) emission in the FRB host galaxy, WALLABY J131913–185018 (hereafter W13–18).
M. Glowacki, K. Lee-Waddell, A. T. Deller, N. Deg, A. C. Gordon, J. A. Grundy, L. Marnoch, A. X. Shen, S. D. Ryder, R. M. Shannon, O. I. Wong, H. Dénes, B. S. Koribalski, C. Murugeshan, J. Rhee, T. Westmeier, S. Bhandari, A. Bosma, B. W. Holwerda, J. X. Prochaska   +19 more
doaj   +1 more source