Publications (14)
Detection and Implications of Laser-Induced Raman Scattering at Astronomical Observatories
F. P. A. Vogt, D. Bonaccini Calia, W. Hackenberg +14
(Abr.) Laser guide stars employed at astronomical observatories provide artificial wavefront reference sources to help correct (in part) the impact of atmospheric turbulence on ast…
ALFA: First Operational Experience of the MPE/MPIA Laser Guide Star System for Adaptive Optics
R. I. Davies, W. Hackenberg, T. Ott +5
The sodium laser guide star adaptive optics system ALFA has been constructed at the Calar Alto 3.5-m telescope. Following the first detection of the laser beacon on the wavefront s…
The ALFA Laser: Beam Relay and Control System
T. Ott, W. Hackenberg, S. Rabien +2
The ALFA laser subsystem uses a 4 watt continuous wave laser beam to produce an artificial guide star in the mesospheric sodium layer as a reference for wavefront sensing. In this…
The ALFA laser guide star: Operation and Results
R. Davies, A. Eckart, W. Hackenberg +4
The importance of laser guide stars to the practical usefulness of adaptive optics cannot be understated, and yet there are very few working systems. This contribution discusses th…
A dynamical measure of the black hole mass in a quasar 11 billion years ago
R. Abuter, F. Allouche, A. Amorim +124
Tight relationships exist in the local universe between the central stellar properties of galaxies and the mass of their supermassive black hole. These suggest galaxies and black h…
Raman-scattered laser guide star photons to monitor the scatter of astronomical telescope mirrors
F. P. A. Vogt, J. L. Ãlvarez, D. Bonaccini Calia +26
The first observations of laser guide star photons Raman-scattered by air molecules above the Very Large Telescope (VLT) were reported in June 2017. The initial detection came from…
The pure-rotational and rotational-vibrational Raman spectrum of the atmosphere at an altitude of 23 km
F. P. A. Vogt, A. Mehner, P. Figueira +5
Ground-based optical astronomical observations supported by or in the vicinity of laser guide-star systems can be contaminated by Raman-scattered laser photons. Anticipating, allev…
Near-infrared adaptive optics observations of galaxy clusters: Abell 262 at z=0.0157, J1836.3CR at z=0.414, and PKS 0743-006 at z=0.994
W. Hackenberg, A. Eckart, R. I. Davies +5
We report on high angular resolution near-infrared (NIR) observations of three galaxy clusters at different redshifts using adaptive optics (AO). In the case of the barred spiral \…
First Observational Results from ALFA with Natural and Laser Guide Stars
R. I. Davies, W. Hackenberg, T. Ott +5
The sodium laser guide star adaptive optics system ALFA, which is installed at the Calar Alto 3.5-m telescope, has been undergoing an intensive optimisation phase. Observations usi…
The ALFA Laser and Analysis Tools
S. Rabien, T. Ott, W. Hackenberg +4
The optimal performance of adaptive optics systems can only be maintained if the wavefront reference is bright and compact. Experience has shown that both of these important criter…
First Light for the GRAVITY+ Adaptive Optics: Extreme Adaptive Optics for the Very Large Telescope Interferometer
GRAVITY+ Collaboration, :, F. Allouche +137
GRAVITY+ improves by orders of magnitude the sensitivity, sky-coverage and contrast of the Very Large Telescope Interferometer (VLTI). A central part of this project is the develop…
Optimization of cw sodium laser guide star efficiency
R. Holzlohner, S. M. Rochester, D. Bonaccini Calia +3
Context: Sodium laser guide stars (LGS) are about to enter a new range of laser powers. Previous theoretical and numerical methods are inadequate for accurate computations of the r…
Multi-Conjugate Adaptive Optics with Laser Guide Stars
R. I. Davies, D. Bonaccini, S. Rabien +8
The Laser Guide Star Facility for the VLT will be commissioned during 2003. This, of course, can only be the first step towards enhancing the scientific output of the VLT through a…
Molecular gas in the galaxy cluster Abell 262. CO observations of UGC 1347 and other galaxies of the cluster
T. Bertram, A. Eckart, M. Krips +2
We present millimeter CO line emission observations of 12 galaxies within the Abell 262 cluster, together with L_FIR data, in the context of a possible molecular gas deficiency wit…