<p><a href="https://www.syfy.com/syfywire/stunning-chaos-in-the-galactic-core" rel="nofollow noreferrer">This article</a> by the Bad Astronomer does a good job of explaining what is visible in the MeerKAT image.The field of view is one by two degrees.</p>

<p>Sa A* is the bright area right of centre, the arc to the left of that may be associated with the Arches cluster. The two bright joined blobs left of that are molecular clouds and further left are some supernova remnants. The filaments scattered over the image are somewhat mysterious but may be aligned with star-forming regions.</p>

CC BY-SA 4.0
2019-04-09T11:43:00.847Z
"What is the scale for example? How would it look pasted into the arc of the Milky Way; just a tiny patch of a few arc-minutes, or several tens of degrees?" Also, do the molecular clouds have names? A good Stack Exchange answer will include all of the main information within the post itself rather than to rely on a link or [leaving part of the answer in as comment under the question](https://astronomy.stackexchange.com/questions/30284/meerkats-epic-image-of-the-galactic-centre-what-are-we-seeing/30288#comment55430_30284). Thanks!
uhoh
CC BY-SA 4.0
2019-04-09T11:13:46.750Z
2019-04-09T12:12:56.137Z
2019-04-09T12:12:56.137Z
MichaelB76
<p><a href="https://doi.org/10.1086/301168" rel="nofollow noreferrer">LaRosa et al 2000</a> present a 90 cm VLA image and catalog of sources near the galactic center.
Here is their schematic diagram with the <a href="https://www.skyandtelescope.com/astronomy-news/60-second-astronomy-news-must-see-images/" rel="nofollow noreferrer">2&deg;x1&deg;, 18-33 cm band</a> MeerKAT image region highlighted.</p>

<p><a href="https://i.sstatic.net/G2Hz9.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/G2Hz9.png" alt="Schematic of galactic center in 90 cm"></a></p>

<p>The compact source Sgr A* is a small dot within the bright, pear-shaped blob <a href="https://en.wikipedia.org/wiki/Sagittarius_A" rel="nofollow noreferrer">Sgr A</a> right of center.
Recent <a href="https://eventhorizontelescope.org/news/lifting-veil-black-hole-heart-our-galaxy-results-gmvaalma-observations-sgr" rel="nofollow noreferrer">millimeter VLBI images</a> (Issaoun et al 2019) indicate a width on the order of 200 &mu;as, or 1/7000 of a pixel in the image you uploaded.</p>

<p>The bright pair of blobs left of center, Sgr B1 and <a href="https://en.wikipedia.org/wiki/Sagittarius_B2" rel="nofollow noreferrer">Sgr B2</a>, are massive <a href="https://en.wikipedia.org/wiki/Molecular_cloud" rel="nofollow noreferrer">molecular clouds</a>.</p>

<p>Most of the bubble shapes are either <a href="https://en.wikipedia.org/wiki/Supernova_remnant" rel="nofollow noreferrer">supernova remnants</a> (SNRs) or <a href="https://en.wikipedia.org/wiki/H_II_region" rel="nofollow noreferrer">H II regions</a> ionized by UV-bright young stars.
The far left pair Sgr D has one of each.</p>

<p>The various non-thermal filaments (NTFs) align with the local magnetic field and emit <a href="https://en.wikipedia.org/wiki/Synchrotron_radiation" rel="nofollow noreferrer">synchrotron radiation</a> but are not well understood otherwise.
The bundle of filaments near the center of the image are known as the galactic center radio arc (GCRA) or just the Arc.</p>

CC BY-SA 4.0
2019-04-09T22:52:08.127Z
*Excellent* graphic, this is all news to me, thank you! I didn't know Sgr had B's, C's, D's and E's or any of these other strange features! I'm seeing our galaxy in a whole new light! (pardon the pun)
uhoh
CC BY-SA 4.0
2019-04-09T21:11:19.020Z
2019-04-09T21:24:16.723Z
2019-04-09T21:24:16.723Z
Mike G
<p>In <a href="https://astronomy.stackexchange.com/a/30280/7982">this answer</a> as well as <a href="https://space.stackexchange.com/a/25744/12102">this one</a>, I've linked to <a href="https://web.njit.edu/~gary/728/Lecture1.html" rel="noreferrer">New Jersey Institute of Technology's Dr. Dale Gary's nicely-written Physics 728 Radio Astronomy; Lecture #1 notes</a> where I can see the image below. It links to Gizmodo.au's <a href="https://www.gizmodo.com.au/2018/07/new-south-african-telescope-releases-epic-image-of-the-galactic-centre/" rel="noreferrer">New South African Telescope Releases Epic Image Of The Galactic Centre</a>.</p>

<p>I have heard of the <a href="https://en.wikipedia.org/wiki/MeerKAT" rel="noreferrer">Meerkat</a> array earlier (<a href="https://astronomy.stackexchange.com/q/16621/7982">Which 16 antenna locations are used for the MeerKAT radio image recently announced?</a>), but I am wondering how to read further about this spectacular image. What is the scale for example? How would it look pasted into the arc of the Milky Way; just a tiny patch of a few arc-minutes, or several tens of degrees?</p>

<p>How will this compare to the radio image of Sag A* that we will see in the next day or two?</p>

<p>Also, if anyone knows, what are those spiky arcs sticking up, and those puff-ball things on the left?</p>

<hr>

<p>Source: <a href="https://www.gizmodo.com.au/2018/07/new-south-african-telescope-releases-epic-image-of-the-galactic-centre/" rel="noreferrer">Gizmodo</a> "The black hole at the centre of the Milky Way and filaments." Credit: SARAO, click for full size.</p>

<p><a href="https://i.sstatic.net/HZYSK.jpg" rel="noreferrer"><img src="https://i.sstatic.net/HZYSK.jpg" alt="Meerkat Epic Image Of The Galactic Centre"></a></p>

CC BY-SA 4.0
2019-04-09T10:46:13.047Z
Found a few details on Apod, field of view is about 2 degrees across. https://apod.nasa.gov/apod/fap/holdMeerKAT.html
MichaelB76
CC BY-SA 4.0
2019-04-09T16:49:46.670Z
That APOD image has some labels which appear when you mouse over it.
Mike G
CC BY-SA 4.0
2019-04-09T16:54:29.957Z
@MikeG oh that is *so cool!* If you mouse-over so that the annotated JPEG is shown, and then open in a new window or save to disk, you can have the annotated version saved. https://i.sstatic.net/Ud07k.jpg A little more work and one could make a GIF with the labels blinking on and off like an old fashioned neon sign. Since that addresses more aspects of my question that the current answer doesn't, consider posting that as a second answer?
uhoh
<radio-astronomy><identify-this-object>
MeerKAT's Epic Image of the Galactic Centre, what are we seeing?
uhoh
# MeerKAT's Epic Image of the Galactic Centre, what are we seeing?

(Asked by: username_0 on 2019-04-09)

In [this answer](https://astronomy.stackexchange.com/a/30280/7982) as well as [this one](https://space.stackexchange.com/a/25744/12102), I've linked to [New Jersey Institute of Technology's Dr. Dale Gary's nicely-written Physics 728 Radio Astronomy; Lecture #1 notes](https://web.njit.edu/~gary/728/Lecture1.html) where I can see the image below. It links to Gizmodo.au's [New South African Telescope Releases Epic Image Of The Galactic Centre](https://www.gizmodo.com.au/2018/07/new-south-african-telescope-releases-epic-image-of-the-galactic-centre/).

I have heard of the [Meerkat](https://en.wikipedia.org/wiki/MeerKAT) array earlier ([Which 16 antenna locations are used for the MeerKAT radio image recently announced?](https://astronomy.stackexchange.com/q/16621/7982)), but I am wondering how to read further about this spectacular image. What is the scale for example? How would it look pasted into the arc of the Milky Way; just a tiny patch of a few arc-minutes, or several tens of degrees?

How will this compare to the radio image of Sag A\* that we will see in the next day or two?

Also, if anyone knows, what are those spiky arcs sticking up, and those puff-ball things on the left?

---

Source: [Gizmodo](https://www.gizmodo.com.au/2018/07/new-south-african-telescope-releases-epic-image-of-the-galactic-centre/) "The black hole at the centre of the Milky Way and filaments." Credit: SARAO, click for full size.

[![Meerkat Epic Image Of The Galactic Centre](https://i.sstatic.net/HZYSK.jpg)](https://i.sstatic.net/HZYSK.jpg)

**Tags:** radio-astronomy, identify-this-object
> **Comments:**
> **username_1**: Found a few details on Apod, field of view is about 2 degrees across. https://apod.nasa.gov/apod/fap/holdMeerKAT.html  
> **username_2**: That APOD image has some labels which appear when you mouse over it.  
> **username_0**: @MikeG oh that is *so cool!* If you mouse-over so that the annotated JPEG is shown, and then open in a new window or save to disk, you can have the annotated version saved. https://i.sstatic.net/Ud07k.jpg A little more work and one could make a GIF with the labels blinking on and off like an old fashioned neon sign. Since that addresses more aspects of my question that the current answer doesn't, consider posting that as a second answer?  

---

## 2 answers

### Answer by username_2 on 2019-04-09. Score: 4 | Accepted answer

[LaRosa et al 2000](https://doi.org/10.1086/301168) present a 90 cm VLA image and catalog of sources near the galactic center.
Here is their schematic diagram with the [2°x1°, 18-33 cm band](https://www.skyandtelescope.com/astronomy-news/60-second-astronomy-news-must-see-images/) MeerKAT image region highlighted.

[![Schematic of galactic center in 90 cm](https://i.sstatic.net/G2Hz9.png)](https://i.sstatic.net/G2Hz9.png)

The compact source Sgr A\* is a small dot within the bright, pear-shaped blob [Sgr A](https://en.wikipedia.org/wiki/Sagittarius_A) right of center.
Recent [millimeter VLBI images](https://eventhorizontelescope.org/news/lifting-veil-black-hole-heart-our-galaxy-results-gmvaalma-observations-sgr) (Issaoun et al 2019) indicate a width on the order of 200 μas, or 1/7000 of a pixel in the image you uploaded.

The bright pair of blobs left of center, Sgr B1 and [Sgr B2](https://en.wikipedia.org/wiki/Sagittarius_B2), are massive [molecular clouds](https://en.wikipedia.org/wiki/Molecular_cloud).

Most of the bubble shapes are either [supernova remnants](https://en.wikipedia.org/wiki/Supernova_remnant) (SNRs) or [H II regions](https://en.wikipedia.org/wiki/H_II_region) ionized by UV-bright young stars.
The far left pair Sgr D has one of each.

The various non-thermal filaments (NTFs) align with the local magnetic field and emit [synchrotron radiation](https://en.wikipedia.org/wiki/Synchrotron_radiation) but are not well understood otherwise.
The bundle of filaments near the center of the image are known as the galactic center radio arc (GCRA) or just the Arc.

> **Comments:**
> **username_0**: *Excellent* graphic, this is all news to me, thank you! I didn't know Sgr had B's, C's, D's and E's or any of these other strange features! I'm seeing our galaxy in a whole new light! (pardon the pun)  

---

### Answer by username_1 on 2019-04-09. Score: 1

[This article](https://www.syfy.com/syfywire/stunning-chaos-in-the-galactic-core) by the Bad Astronomer does a good job of explaining what is visible in the MeerKAT image.The field of view is one by two degrees.

Sa A\* is the bright area right of centre, the arc to the left of that may be associated with the Arches cluster. The two bright joined blobs left of that are molecular clouds and further left are some supernova remnants. The filaments scattered over the image are somewhat mysterious but may be aligned with star-forming regions.

> **Comments:**
> **username_0**: "What is the scale for example? How would it look pasted into the arc of the Milky Way; just a tiny patch of a few arc-minutes, or several tens of degrees?" Also, do the molecular clouds have names? A good Stack Exchange answer will include all of the main information within the post itself rather than to rely on a link or [leaving part of the answer in as comment under the question](https://astronomy.stackexchange.com/questions/30284/meerkats-epic-image-of-the-galactic-centre-what-are-we-seeing/30288#comment55430_30284). Thanks!  

---

