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Questions tagged [interferometry]

Questions about astronomical observations which involve superimposing waves received by multiple, physically separated, receivers to obtain higher angular resolution.

3 votes
0 answers
432 views

Are they really sure this isn't an Airy disk? How was that ruled out?

How do they know that this is a spherical shell of gas, and not just something like an Airy pattern-like artifact produced by the VLT's large interferometric aperture? Image from: https://www.eso.org/...
uhoh's user avatar
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2 votes
1 answer
119 views

What does a narrow-band "point spread function" look like for long exposures from the VLT's large interferometric aperture?

In interferometric radio astronomy UV plots are the first step in understanding what a point spread function (PSF) will look like for a given location in the sky observed over a period of time. The ...
uhoh's user avatar
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1 vote
1 answer
302 views

Can the interferometer called "Gravity" measure "a few centimeters on the Moon"?

Phys.org's Very Large Telescope sees star dance around supermassive black hole, proves Einstein right links to several ESO videos, including Interview with Reinhard Genzel (in English). After ...
uhoh's user avatar
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22 votes
1 answer
595 views

Multi-messenger astronomy: what is the potential of simultaneous detection of gravitational waves and neutrinos from a supernova?

Thanks to the efforts of the aLIGO team, gravitational wave astronomy is a reality. At the same time, neutrino detectors like Hyperkamiokande are becoming much more sensitive. My question is: what ...
ProfRob's user avatar
  • 156k
13 votes
2 answers
258 views

Why hasn't VLBI been used to try and image giant exoplanets?

A Jupiter-sized object at 10 pc subtends an angle of 0.0001 arcseconds (100 micro-arcsec) at the Earth. The Event Horizon Telescope interferometry network is capable of a (demonstrated) angular ...
ProfRob's user avatar
  • 156k
5 votes
0 answers
106 views

Estimate the number of pixels required to map the full primary beam of a Radio Telescope station

I am practising some exam questions for a radio interferometry exam, and I am struggling with this question: The physical size of a single LOFAR station, operating at 150MHz is about 50m. Estimate ...
Naz's user avatar
  • 163
3 votes
1 answer
384 views

Estimate upper limits on flux values in the case of a non-detection?

I have ALMA data which are non-detections of some spectral lines in a protoplanetary disk. The data is in the form of spectral cubes. I am hoping to estimate an upper limit on the flux of each of the ...
lucas's user avatar
  • 1,386
3 votes
1 answer
96 views

What are the challenges for the building and data analysis of the CHIME telescope?

The Canadian Hydrogen Intensity Mapping Experiment (CHIME) has discovered the second repeated fast radio burst recently. However, its structure is simple apparently. I wonder why we did not build a ...
questionhang's user avatar
  • 3,137
3 votes
1 answer
158 views

Could the E.H.T. produce an image of the human artifacts on the moon?

Two days ago the New York Times featured the Event Horizon Telescope (E.H.T.), a huge virtual radio telescope emerging from combining data from several dishes scattered around the world. While the E.H....
Peter - Reinstate Monica's user avatar
2 votes
2 answers
103 views

Why does the Simbad page "A.A. Michelson's Jovian Galilean-satellite interferometer" show data for Betelgeuse?

When searching for things related to How did Michelson measure the diameters of jupiter's moons using optical interferometry? I came across the ui.adsabs.harvard.edu entry A. A. Michelson's Jovian ...
uhoh's user avatar
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2 votes
1 answer
183 views

How is VLBI delay calculated?

I’m working on a research project wherein we are trying to solve a problem very similar to VLBI delay. We have two radio receivers, and we know their locations. We also know at what time one receiver ...
PerplexedDimension's user avatar
2 votes
1 answer
128 views

How do they know the non-uniformities seen on the disk of π¹ Gru are real and not artifacts?

@RobJeffries' answer to What is this web on the surface of the Sun? explains why convection cells on some other stars can be far larger than they are on our Sun and includes a near-infrared VLT ...
uhoh's user avatar
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