High‐Resolution Spectra of Intrinsic Absorption Lines in the Quasi‐stellar Object UM 675

1997 ◽  
Vol 478 (1) ◽  
pp. 80-86 ◽  
Author(s):  
Fred Hamann ◽  
Thomas A. Barlow ◽  
Vesa Junkkarinen ◽  
E. M. Burbidge
Keyword(s):  
High Resolution ◽  
Stellar Object ◽  
Absorption Lines ◽  
Intrinsic Absorption

Time‐variable Intrinsic Absorption Lines in the Quasi‐stellar Object Q2343+125

1997 ◽  
Vol 478 (1) ◽  
pp. 87-93 ◽  
Author(s):  
Fred Hamann ◽  
Thomas A. Barlow ◽  
Vesa Junkkarinen
Keyword(s):  
Time Variable ◽  
Stellar Object ◽  
Absorption Lines ◽  
Intrinsic Absorption

scholarly journals HIGH-RESOLUTION MID-INFRARED SPECTROSCOPY OF NGC 7538 IRS 1: PROBING CHEMISTRY IN A MASSIVE YOUNG STELLAR OBJECT

2009 ◽  
Vol 696 (1) ◽  
pp. 471-483 ◽  
Author(s):  
Claudia Knez ◽  
John H. Lacy ◽  
Neal J. Evans ◽  
Ewine F. van Dishoeck ◽  
Matthew J. Richter
Keyword(s):  
Infrared Spectroscopy ◽  
High Resolution ◽  
Stellar Object ◽  
Mid Infrared ◽  
Mid Infrared Spectroscopy ◽  
Young Stellar Object

High Resolution Spectroscopy of Absorption Lines in the Z = 1.7 BL LAC Object 0215+015

Quasars ◽  
1986 ◽  
pp. 571-572
Author(s):  
J. Chris Blades ◽  
Richard W. Hunstead ◽  
Hugh S. Murdoch ◽  
Max Pettini
Keyword(s):  
High Resolution ◽  
Absorption Lines ◽  
High Resolution Spectroscopy ◽  
Bl Lac

Absorption Lines in the Spectra of the QSO PKS 1448-232

1984 ◽  
Vol 5 (3) ◽  
pp. 355-359 ◽  
Author(s):  
Chen Jian-sheng ◽  
Donald C. Morton ◽  
Bruce A. Peterson ◽  
Alan E. Wright ◽  
David L. Jauncey
Keyword(s):  
Radio Source ◽  
Stellar Object ◽  
Absorption Lines ◽  
Ultraviolet Excess ◽  
Low Resolution ◽  
Optical Position

Savage et al. (1977) found that the radio source PKS 1448-232 coincided with a stellar object of about magnitude 16.4 having an ultraviolet excess. A low resolution spectrum obtained with the Anglo-Australian Telescope (AAT) confirmed this object as a QSO with zem = 2.22 and revealed many absorption lines short-ward of the La emission. Consequently this object was included in a programme of spectroscopy at intermediate resolution with the AAT to investigate QSO absorption lines. Savage et al. have given a finding chart with an optical position of 14h48m09s.3, −23°17′10″ (1950.0). The radio fluxes are 0.40 Jy at 2.7 GHz and 0.31 Jy at 5.0 GHz.

High‐Resolution X‐Ray and Ultraviolet Spectroscopy of the Complex Intrinsic Absorption in NGC 4051 withChandraand theHubble Space Telescope

2001 ◽  
Vol 557 (1) ◽  
pp. 2-17 ◽  
Author(s):  
M. J. Collinge ◽  
W. N. Brandt ◽  
Shai Kaspi ◽  
D. Michael Crenshaw ◽  
Martin Elvis ◽  
...  
Keyword(s):  
High Resolution ◽  
Ultraviolet Spectroscopy ◽  
Space Telescope ◽  
X Ray ◽  
Intrinsic Absorption ◽  
Ngc 4051

Einfluß der Rotation auf die Lebensdauer prädissoziierender Moleküle

1971 ◽  
Vol 26 (3) ◽  
pp. 538-546 ◽  
Author(s):  
F. J. Comes ◽  
G. Schumpe
Keyword(s):  
High Resolution ◽  
Excellent Agreement ◽  
Rotational Motion ◽  
Absorption Lines ◽  
Rare Gases ◽  
Rotational States ◽  
Theoretical Predictions ◽  
Line Widths

Abstract The D 1∏u - X1∑g+system of H2 and D2 shows strong predissociation. High resolution m easurements on the line widths of isolated absorption lines have been carried out, showing the influence of rotation on the predissociation probability of the corresponding rotational states. Their lifetime decreases with increasing rotation of the molecule and with decreasing mass due to the coupling of electronic and rotational motion. Both results are in excellent agreement with theoretical predictions given by Kronig. The shape of the absorption lines broadened by predissociation was found to be typically asymmetric. They are of the Beutler type, well known form the autoionisation of the rare gases.

The origin of the quasi-stellar object absorption lines

1991 ◽  
Vol 377 ◽  
pp. 39 ◽  
Author(s):  
S. M. Viegas ◽  
R. B. Gruenwald
Keyword(s):  
Stellar Object ◽  
Absorption Lines

A Discussion on astronomy in the ultraviolet - The ultraviolet spectrum of B-type supergiants

1975 ◽  
Vol 279 (1289) ◽  
pp. 429-442
Keyword(s):  
High Resolution ◽  
Spectral Type ◽  
Main Sequence ◽  
Ultraviolet Spectrum ◽  
Absorption Lines ◽  
Light Elements ◽  
Main Sequence Stars ◽  
Complete Identification ◽  
Constant Strength

The broad, steep-sided absorption lines in B-type supergiant spectra are stronger than the absorption lines in main-sequence stars. In addition to lines from the second, third and fourth spectra of the light elements and the metals there is a broad, pointed feature at 1720 A which has constant strength in the B-type supergiants regardless of spectral type. The complete identification of this blend is not known. At high resolution the ultraviolet resonance lines of C iv, N v, Si hi and Si iv in the spectra of OB supergiants are shortward displaced by velocities up to 1800 km s-1 indicating the presence of an escaping atmosphere. At type B5 the expanding atmosphere is moving at about 120 km s-1 which means that the material is probably brought to rest before it escapes from the star. Evidence is presented of the presence of a stationary shell around the B5Ia supergiant q Canis Majoris as well as a slowly expanding atmosphere.

scholarly journals Studies of the ISM in the LMC using SN1987A

1991 ◽  
Vol 148 ◽  
pp. 431-431
Author(s):  
Max Pettini
Keyword(s):  
High Resolution ◽  
Interstellar Medium ◽  
Large Scale ◽  
Signal To Noise Ratio ◽  
Three Dimensional ◽  
Large Magellanic Cloud ◽  
Absorption Lines ◽  
High Signal ◽  
Hii Region ◽  
Sn 1987A

The exceptional brightness of SN1987A provided a wealth of opportunities for probing not only the interstellar medium in our Galaxy and in the Large Magellanic Cloud (LMC), but also any intergalactic matter between the two. Spectroscopic work has been directed both towards searches for very weak absorption lines, which require data of exceptionally high signal-to-noise ratio, and towards recording spectra of known features at unprecedentedly high resolution. Both approaches have yielded exciting and unexpected results. The first detection of [FeX] absorption has revealed the presence of million-degree gas in the interstellar medium of the LMC, possibly resulting from the explosions of previous supernovae in the 30-Doradus HII region. The ultra-high-resolution observations have been successful in resolving the hyperfine structure of the sodium D lines in several interstellar clouds along the line of sight to the supernova. This implies that the clouds are at temperatures of, at most, 170 K and have internal turbulent velocities of not more than 0.2 km s−1; large-scale motions thus appear to be mainly subsonic in these clouds. Radio observations of HI emission at 21-cm with the Parkes telescope have been combined with measurements of a variety of ultraviolet absorption lines, obtained with the International Ultraviolet Explorer satellite, to give the most detailed picture yet of the chemical composition of the gas between the Galaxy and the LMC. Finally, photographic monitoring of the light echo of SN 1987A over the last two years has provided a three-dimensional view of the interstellar environment in which SN 1987A exploded, complementing vividly the information deduced from the spectroscopic results.

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