- TERAHERTZ OBSERVING TECHNIQUES

2015 ◽  
pp. 278-301
Keyword(s):  
Observing Techniques

scholarly journals Observing techniques for astronomical laser guide star adaptive optics

1998 ◽  
Author(s):  
Claire E. Max ◽  
Bruce A. Macintosh ◽  
Scot S. Olivier ◽  
Donald T. Gavel ◽  
Herbert W. Friedman
Keyword(s):  
Adaptive Optics ◽  
Laser Guide Star ◽  
Guide Star ◽  
Laser Guide ◽  
Observing Techniques

scholarly journals The eclipses of the black widow pulsar J1810+1744 at low radio frequencies

2017 ◽  
Vol 13 (S337) ◽  
pp. 396-397
Author(s):  
Elliott J. Polzin ◽  
Rene P. Breton ◽  
Ben W. Stappers ◽  
Keyword(s):  
Orbital Period ◽  
Line Of Sight ◽  
Dispersion Measure ◽  
Interferometric Imaging ◽  
Black Widow ◽  
Low Frequencies ◽  
Small Deviations ◽  
Imaging Mode ◽  
High Band ◽  
Observing Techniques

AbstractHere we present a study of the radio frequency eclipses of the black widow pulsar J1810+1744 at low frequencies, where we are most sensitive to small deviations in the effects of material along the line of sight. Utilising the simultaneous dual beamforming and interferometric (imaging) mode of LOFAR High Band Antenna, pulsar flux variations throughout the orbit are compared for the two observing techniques to test for the presence of scattering and absorption at eclipse orbital phases. Dispersion measure and scattering variations are used as a sensitive probe into outermost edges of the eclipsing material surrounding the companion star. We find the eclipsing medium to be variable on timescales shorter than the 3.6 hr orbital period, and propose cyclotron-synchrotron absorption as the most likely primary eclipse mechanism.

scholarly journals Dispersion of Interstellar Polarization

1965 ◽  
Vol 7 ◽  
pp. 57-64
Author(s):  
Thomas Gehrels
Keyword(s):  
Data Processing ◽  
High Altitude ◽  
Wavelength Range ◽  
Wavelength Dependence ◽  
Probable Error ◽  
Percentage Polarization ◽  
University Of Arizona ◽  
The University ◽  
Observing Techniques

The Wavelength Dependence of Polarization as observed in 32 stars, for which the Henry Draper numbers are given, is shown in figure 1. Details of some of these observations are presented in reference 1.The equipment is now being used with the new 154-cm Catalina reflector of the Lunar and Planetary Laboratory at the University of Arizona. The instrumental polarizations are nearly zero. The data processing and observing techniques have been further improved; the precision is mainly determined by statistics such that the internal probable error in the percentage polarization is ±0.03 percent (±0.0006 magnitude) for a half-hour observation per filter on objects brighter than about 7 magnitudes. The wavelength λ ranges from 0.33 to 0.95 μ covered by seven filters of bandwidth of about 0.05 μ. The wavelength range is being extended to 1.2, 1.6, and 2.2 μ and, with high-altitude ballooning, to 0.28 and 0.22 μ.

scholarly journals Focal Reducer Techniques for Direct Imaging and Field Spectroscopy with Large Telescopes

1984 ◽  
Vol 79 ◽  
pp. 575-583 ◽  
Author(s):  
Edward H. Geyer ◽  
Bruno Nelles
Keyword(s):  
Radial Velocity ◽  
Direct Imaging ◽  
Field Spectroscopy ◽  
Large Telescopes ◽  
Observing Techniques

AbstractTo exploit the full effectiveness of large ground based telescopes, the focal reducer technique can be applied very adequately. We review recent Hoher List observatory developments of observing techniques for direct imaging, field spectroscopy with multi-slit and masking methods for background supression and double-grism arrangements (heliometer principle)for absolute radial velocity determinations with a focal reducer field spectrograph.

scholarly journals HI Multibeam Survey Techniques

1997 ◽  
Vol 14 (1) ◽  
pp. 111-116 ◽  
Author(s):  
Lister Staveley-Smith
Keyword(s):  
Working Group ◽  
Sky Surveys ◽  
Survey Techniques ◽  
Advantages And Disadvantages ◽  
Observing Techniques

AbstractThe parameters of the HI Parkes All-Sky Surveys (HIPASS), as proposed by the Multibeam Survey Working Group, are described, as are the advantages and disadvantages of various multibeam observing techniques, including telescope scanning. The best techniques, in terms of minimising the variance in image sensitivity, are calculated. Some of the observing techniques may be applicable to other multibeam surveys.

Radio Transients in the Era of Multi-Messenger Astrophysics

2017 ◽  
Vol 14 (S339) ◽  
pp. 207-214
Author(s):  
G. E. Anderson ◽  
B. W. Stappers ◽  
I. Andreoni ◽  
M. Caleb ◽  
D. Coppejans ◽  
...  
Keyword(s):  
Radio Emission ◽  
Cataclysmic Variable ◽  
Radio Bursts ◽  
Tidal Disruption ◽  
Square Kilometre Array ◽  
Long Baseline ◽  
Science Question ◽  
Radio Transients ◽  
Detailed Imaging ◽  
Observing Techniques

AbstractRadio emission from astrophysical transients allows us to derive calorimetry of kinetic feedback and detailed imaging in ways that are not possible at other wavelengths, and as such it forms an important part of the multi-messenger follow-ups of these events. The field is burgeoning, with a renaissance of interest in accretion, stellar explosions and jetted supernovæ, alongside newer classes of phenomena such as fast radio bursts and tidal disruption events. The purpose of this workshop was to discuss the infrastructure and techniques for detecting, identifying and probing radio transients, with a particular focus on how best to exploit transient alerts from multi-messenger facilities. We examined the type of transient alerts those facilities will broadcast, and methods for following them up, such as rapid-response triggering and shadowing. In break-out groups, participants chose a science question related to a particular radio transient type or class and discussed whether the planned transient strategies and observing techniques on the Square Kilometre Array will be adequate to address the particular question. The classes they chose included fast radio bursts, supernovæ, cataclysmic variable and unknown transients. Any proposed adaptation or suggestion was relayed to a panel of experts for further discussion. The second part of the workshop concentrated on the application of long baseline interferometry for detecting and measuring radio transients.

scholarly journals Dark cloud observations: Problems and progress

1997 ◽  
Vol 178 ◽  
pp. 173-182
Author(s):  
Y. C. Minh
Keyword(s):  
High Resolution ◽  
Interstellar Medium ◽  
Recent Progress ◽  
High Resolution Spectroscopy ◽  
Significant Progress ◽  
Dark Cloud ◽  
Dark Clouds ◽  
Number Of Species ◽  
Observing Techniques ◽  
Made In

Interstellar dark clouds have provided a laboratory which has been successfully used to identify a number of species, perform high resolution spectroscopy, and characterize the processes in the interstellar medium. We have successfully solved a number of problems and achieved significant progress through dark cloud observations. With the improvement of observing techniques and theories, however, we are now having new problems and are waiting for further progress. The dark clouds, because of their quietness and large column densities, still provide a very useful testing ground of many uncertain interstellar processes. Here we summarize some of the recent progress made in dark cloud observations and discuss related problems. We focus especially on the importance of nearby objects, possible signs of gas-grain interactions in dark clouds, and further sensitive observations.

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