<blockquote>
<p>Is there work underway to increase the number of radiotelescope sites around the Earth with circa 1 THz receivers to push the long baseline capabilities of the Event Horizon Telescope to sub-millimeter wavelengths?</p>
</blockquote>
<p>Yes, regarding the Event Horizon Telescope network itself, <a href="https://iopscience.iop.org/article/10.3847/1538-3881/abc3c3" rel="nofollow noreferrer">this</a> recent paper evaluates the efficacy of 40 new sites for observing submilimeter wavelengths at <span class="math-container">$\sim$</span> THz (really <span class="math-container">$\approx$</span> 300 GHz). They conclude that <em>&quot;A group of new sites with favorable transmittance and geographic placement leads to greatly enhanced imaging and science on horizon scales.</em></p>
<p>On a longer developmental timescale, there's also this white paper which proposes a space-based observatory <a href="https://arxiv.org/abs/1908.10767" rel="nofollow noreferrer">TeraHertz Exploration and Zooming-in for Astrophysics (THEZA)</a>, which would aim to observe the THz regime. From the abstract:</p>
<blockquote>
<p>The concept will open up a sizeable range of hitherto unreachable parameters of observational astrophysics. It unifies two major lines of development of space-borne radio astronomy of the past decades: Space VLBI (Very Long Baseline Interferometry) and mm- and sub-mm astrophysical studies with &quot;single dish&quot; instruments. It also builds upon the recent success of the Earth-based Event Horizon Telescope (EHT) -- the first-ever direct image of a shadow of the super-massive black hole in the centre of the galaxy M87. As an amalgam of these three major areas of modern observational astrophysics, THEZA aims at facilitating a breakthrough in high-resolution high image quality studies in the millimetre and sub-millimetre domain of the electromagnetic spectrum.</p>
</blockquote>

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2022-02-13T08:56:59.393Z
2022-02-13T12:37:38.497Z
2022-02-13T12:37:38.497Z
Daddy Kropotkin
<p>The Max Planck Institute for Radio Astronomy's press release <a href="https://www.mpifr-bonn.mpg.de/pressreleases/2020/4" rel="nofollow noreferrer">Something is Lurking in the Heart of Quasar 3C 279; First Event Horizon Telescope Images of a Black-Hole Powered Jet</a> shows a stunning montage of three Event Horizon telescope images at 7, 3 and 1.3 mm wavelengths (43, 86 and 230 GHz) demonstrating how the highest frequency in combination with the planet-sized baselines work together to produce observations at &quot;an extreme 20 microarcsecond resolution&quot;, quoting the title of the April 5 2020 Astronomy and Astrophysics paper Kim et al. 2020 <a href="https://www.aanda.org/articles/aa/pdf/forth/aa37493-20.pdf" rel="nofollow noreferrer">Event Horizon Telescope imaging of the archetypal blazar 3C 279 at an extreme 20 microarcsecond resolution</a>.</p>
<p>From <a href="https://astronomy.stackexchange.com/q/28666/7982">How does ALMA produce stable, mutually coherent ~THz local oscillators for all of their dishes?</a> I know that ALMA's receivers can go as far as about 950 GHz.</p>
<p><strong>Question:</strong> Is there work underway to increase the number of radiotelescope sites around the Earth <em>with circa 1 THz receivers</em> to push the long baseline capabilities of the Event Horizon Telescope to sub-millimeter wavelengths?</p>

<black-hole><radio-astronomy><radio-telescope><event-horizon-telescope>
Is there any work underway to push the long baseline capabilities of the Event Horizon Telescope to sub-millimeter wavelengths?
uhoh
# Is there any work underway to push the long baseline capabilities of the Event Horizon Telescope to sub-millimeter wavelengths?

(Asked by: username_0 on 2020-04-07)

The Max Planck Institute for Radio Astronomy's press release [Something is Lurking in the Heart of Quasar 3C 279; First Event Horizon Telescope Images of a Black-Hole Powered Jet](https://www.mpifr-bonn.mpg.de/pressreleases/2020/4) shows a stunning montage of three Event Horizon telescope images at 7, 3 and 1.3 mm wavelengths (43, 86 and 230 GHz) demonstrating how the highest frequency in combination with the planet-sized baselines work together to produce observations at "an extreme 20 microarcsecond resolution", quoting the title of the April 5 2020 Astronomy and Astrophysics paper Kim et al. 2020 [Event Horizon Telescope imaging of the archetypal blazar 3C 279 at an extreme 20 microarcsecond resolution](https://www.aanda.org/articles/aa/pdf/forth/aa37493-20.pdf).

From [How does ALMA produce stable, mutually coherent ~THz local oscillators for all of their dishes?](https://astronomy.stackexchange.com/q/28666/7982) I know that ALMA's receivers can go as far as about 950 GHz.

**Question:** Is there work underway to increase the number of radiotelescope sites around the Earth *with circa 1 THz receivers* to push the long baseline capabilities of the Event Horizon Telescope to sub-millimeter wavelengths?

**Tags:** black-hole, radio-astronomy, radio-telescope, event-horizon-telescope

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## 1 answers

### Answer by username_1 on 2022-02-13. Score: 2 | Accepted answer

> Is there work underway to increase the number of radiotelescope sites around the Earth with circa 1 THz receivers to push the long baseline capabilities of the Event Horizon Telescope to sub-millimeter wavelengths?

Yes, regarding the Event Horizon Telescope network itself, [this](https://iopscience.iop.org/article/10.3847/1538-3881/abc3c3) recent paper evaluates the efficacy of 40 new sites for observing submilimeter wavelengths at $\sim$ THz (really $\approx$ 300 GHz). They conclude that *"A group of new sites with favorable transmittance and geographic placement leads to greatly enhanced imaging and science on horizon scales.*

On a longer developmental timescale, there's also this white paper which proposes a space-based observatory [TeraHertz Exploration and Zooming-in for Astrophysics (THEZA)](https://arxiv.org/abs/1908.10767), which would aim to observe the THz regime. From the abstract:

> The concept will open up a sizeable range of hitherto unreachable parameters of observational astrophysics. It unifies two major lines of development of space-borne radio astronomy of the past decades: Space VLBI (Very Long Baseline Interferometry) and mm- and sub-mm astrophysical studies with "single dish" instruments. It also builds upon the recent success of the Earth-based Event Horizon Telescope (EHT) -- the first-ever direct image of a shadow of the super-massive black hole in the centre of the galaxy M87. As an amalgam of these three major areas of modern observational astrophysics, THEZA aims at facilitating a breakthrough in high-resolution high image quality studies in the millimetre and sub-millimetre domain of the electromagnetic spectrum.


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