astronomy

NGC 4593

NGC 4593 is a astronomy topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand NGC 4593 rather than just read about it. In short: NGC 4593 is a barred spiral galaxy located in the constellation Virgo. It is located at a distance of about 120 million light years from Earth, which, given its apparent dimensions, means that NGC 4593 is about 125,000 light years across.

Key takeaways

NGC 4593 belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect NGC 4593 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of NGC 4593 from memory before moving on to harder problems.

Reference excerpt

NGC 4593 is a barred spiral galaxy located in the constellation Virgo. It is located at a distance of about 120 million light years from Earth, which, given its apparent dimensions, means that NGC 4593 is about 125,000 light years across. It was discovered by William Herschel on April 17, 1784. It is a Seyfert galaxy.

Characteristics NGC 4593 is a barred spiral galaxy with a nearly complete ring. The galaxy has a large elliptical/boxy pseudobulge with the bar emerging from its northeast and southwest corner. From its end of the bar begin two diffuse smooth spiral arms that can be traced for about half a revolution. At the south part of the ring there could emerge a third, smaller spiral arm. One arm emerges from the ring at one end of the bar while a second emerges about 15 degrees before the other end.

Active nucleus

The nucleus of NGC 4593 has been found to be active and it has been categorised as a type I Seyfert galaxy. The most accepted theory for the energy source of active galactic nuclei is the presence of an accretion disk around a supermassive black hole. The mass of the black hole in the centre of NGC 4593 is estimated to be (9.8±2.1)×106 M☉ based on reverberation mapping or (5.8±2.1)×106 M☉ based on X-ray flux variations. The nucleus has been found to be a bright X-rays source. The source is variable both in flux and spectrum, varying at a timescale of few kiloseconds. The changes in the X-ray band are followed by variations in the ultraviolet and visual light band, with the lag being 1.3 ± 0.5 days in the V-band. The X-rays observations by Chandra X-ray Observatory indicate the presence of a warm absorber and outflows of ionised gas that are generated at different distances from the nucleus. The overall X-ray spectrum indicates the presence of a hot corona, which generates the hard X-rays, and a warm medium, which is responsible for the soft X-rays excess. A circumnuclear dust ring with a radius of 5 arcseconds that is connected with the dust lanes in the bar of the galaxy is seen in visible light. Similar rings in other galaxies have been found to exhibit intense star formation, but that isn't the case with NGC 4593, indicating that starburst activity is episodic. Inside the ring lies a single spiral arm and no other dust features.

Nearby galaxies NGC 4593 is the foremost galaxy in a galaxy group known as the NGC 4593 Group. Other members of the group the spiral galaxy NGC 4602 and the smaller galaxies MCG-01-32-37, MGC-01-32-33, SVEN 314, and SVEN 328. Markarov et al. consider NGC 4604 to be a member of this group as well. SVEN 314 is a dwarf galaxy which lies at a projected distance of 22 kpc and is the closest galaxy to NGC 4593. There are evidence that NGC 4593 is interacting with MGC-01-32-33, which lies about two disk radii away, as the spiral pattern is slightly distorted towards the direction of that galaxy, possibly as a result of tidal forces. Other galaxies near the NGC 4593 Group include UGC 7798 and its group, IC 804, NGC 4626, NGC 4628, and NGC 4671. These galaxies were considered to be part of the Virgo II Groups, but that isn't accepted anymore, and they are considered to lie between the Local Supercluster and Hydra-Centaurus Supercluster, with the group still being within the Local Supercluster.

References

External links

NGC 4593 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images NGC 4593 on SIMBAD

Illustrations

Worked examples

Example 1 — a first encounter with NGC 4593

Start with the simplest possible case. Write down what NGC 4593 claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In astronomy, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to NGC 4593 before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about NGC 4593 ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of NGC 4593

In research: NGC 4593 appears in astronomy research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses NGC 4593 in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: NGC 4593 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Astronomical objects discovered in 1784, Barred spiral galaxies, Discoveries by William Herschel, so understanding it makes those chapters shorter.
In everyday life: Look for NGC 4593 outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study NGC 4593 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what NGC 4593 means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain NGC 4593 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is NGC 4593 in simple terms?

Why does NGC 4593 matter?

Because it connects several astronomy ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study NGC 4593?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on NGC 4593.