Direct imaging of the twin QSOs 0957 + 561 A and B: the gravitational lens interpretation

Nature ◽  
1979 ◽  
Vol 282 (5735) ◽  
pp. 183-185 ◽  
Author(s):  
Mark T. Adams ◽  
Todd A. Boroson
Keyword(s):  
Gravitational Lens ◽  
Direct Imaging

scholarly journals Ground-Based And HST Direct Imaging Of HLQs

1996 ◽  
Vol 173 ◽  
pp. 387-392
Author(s):  
J. Surdej ◽  
A.O. Jaunsen ◽  
J.-F. Claeskens ◽  
S. Gonzaga ◽  
A. Pospieszalska-Surdej ◽  
...  
Keyword(s):  
Gravitational Lensing ◽  
Mass Range ◽  
Compact Objects ◽  
Gravitational Lens ◽  
The Internet ◽  
Direct Imaging ◽  
Large Sample ◽  
The Galaxy ◽  
Number Counts

In the context of our studies on gravitational lensing effects among Highly Luminous Quasars (HLQs), we are presently compiling at STScI an archive of direct CCD frames for more than 1000 bright quasars observed with HST and ground-based telescopes. This archive will soon become publicly accessible through the Internet. On the basis of these observations, we are pursuing in a systematic way the analysis (subtraction of numerical PSFs and/or deconvolution) of the HLQ images in order to detect multiple QSO images and/or nearby foreground galaxies at very small angular separations. Residual images corresponding to several new possible multiply imaged HLQs are presented here. From the observed number and image configuration of gravitational lens candidates identified in this large sample of HLQs, it is possible to infer realistic values for parameters characterizing the galaxy deflectors, the number counts of quasars, etc. (cf. Claeskens et al. 1995ab), and also to set interesting constraints on the cosmological density of compact objects in the mass range 1010 ‒ 1012M⊙.

Seti Space Missions

1997 ◽  
Vol 161 ◽  
pp. 761-776 ◽  
Author(s):  
Claudio Maccone
Keyword(s):  
Electromagnetic Waves ◽  
Space Missions ◽  
Gravitational Lens ◽  
The Sun ◽  
Space Antenna ◽  
Focal Distance ◽  
Large Space ◽  
The Earth ◽  
Space Antennas ◽  
New Space

AbstractSETI from space is currently envisaged in three ways: i) by large space antennas orbiting the Earth that could be used for both VLBI and SETI (VSOP and RadioAstron missions), ii) by a radiotelescope inside the Saha far side Moon crater and an Earth-link antenna on the Mare Smythii near side plain. Such SETIMOON mission would require no astronaut work since a Tether, deployed in Moon orbit until the two antennas landed softly, would also be the cable connecting them. Alternatively, a data relay satellite orbiting the Earth-Moon Lagrangian pointL2would avoid the Earthlink antenna, iii) by a large space antenna put at the foci of the Sun gravitational lens: 1) for electromagnetic waves, the minimal focal distance is 550 Astronomical Units (AU) or 14 times beyond Pluto. One could use the huge radio magnifications of sources aligned to the Sun and spacecraft; 2) for gravitational waves and neutrinos, the focus lies between 22.45 and 29.59 AU (Uranus and Neptune orbits), with a flight time of less than 30 years. Two new space missions, of SETI interest if ET’s use neutrinos for communications, are proposed.

Shaped and apodized apertures for direct imaging of extra solar planets

2004 ◽  
Vol 12 ◽  
pp. 65-87 ◽  
Author(s):  
C. Aime
Keyword(s):  
Direct Imaging

A Spectroscopic Study of the Environments of Gravitational Lens Galaxies

2006 ◽  
Vol 20 ◽  
pp. 289-290
Author(s):  
I. Momcheva ◽  
K. Williams ◽  
C. Keeton ◽  
A. Zabludoff
Keyword(s):  
Spectroscopic Study ◽  
Gravitational Lens ◽  
Lens Galaxies

Simulation of a gravitational lens in a lecture demonstration

1982 ◽  
Vol 138 (9) ◽  
pp. 147 ◽  
Author(s):  
G.S. Egorov ◽  
Nikolai S. Stepanov
Keyword(s):  
Gravitational Lens ◽  
Lecture Demonstration

Study A Non-Spherically Symmetric Gravitational Lens

2016 ◽  
pp. 1
Author(s):  
Tarig S. El Mabrouk
Keyword(s):  
Gravitational Lens ◽  
Spherically Symmetric

scholarly journals Introduction

1995 ◽  
Vol 167 ◽  
pp. 3-7
Author(s):  
A. G. Davis Philip
Keyword(s):  
Large Field ◽  
Direct Imaging ◽  
Ir Detector ◽  
New Developments ◽  
Detector Arrays ◽  
Array Detectors ◽  
Poster Sessions ◽  
Array Technology ◽  
The Subject ◽  
Scientific Results

A short introduction to the subject of the meeting, IAU Symposium No. 167, New Developments in Array Technology and Applications is given. CCD and Array detectors have become the detectors of choice at optical observatories all over the world. Direct imaging, photometry and spectroscopy are all vastly improved as a result. Thirteen IAU Commissions joined in sponsoring this meeting which indicates the wide interest in this subject. In the five days of the symposium the following topics were discussed: New Developments in CCD Technology, New Developments in IR Detector Arrays, Direct Imaging with CCDs and Other Arrays, Spectroscopy with CCDs and Other Arrays and Large Field Imaging with Array Mosaics. A few papers concerning Astrometry with CCDs were given in the poster sessions. Scientific results were also presented in the poster sessions.

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