astronomy

PKS 0442−28

PKS 0442−28 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 PKS 0442−28 rather than just read about it. In short: PKS 0442−28 is a narrow-line radio galaxy located in the constellation of Eridanus. The redshift of the galaxy is (z) 0.151 and it was first discovered as an astronomical radio source by astronomers lead by J.G.

Key takeaways

PKS 0442−28 belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect PKS 0442−28 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of PKS 0442−28 from memory before moving on to harder problems.

Reference excerpt

PKS 0442−28 is a narrow-line radio galaxy located in the constellation of Eridanus. The redshift of the galaxy is (z) 0.151 and it was first discovered as an astronomical radio source by astronomers lead by J.G. Bolton in December 1965.

Description PKS 0442−28 is classified as a Type 2 Fanaroff-Riley Class radio galaxy. Its host is an elliptical galaxy based on a de Vaucouleurs model. The total dust mass of the galaxy is estimated to be <6.5 M☉. It also has been classified as a Seyfert type 2 galaxy. It has a total flux density of 22.0 ± 0.3 mJy at 24 ɥm and 31.0 ± 5.0 at 70 ɥm. The host galaxy has a shell-like structure 50 kiloparsecs from the central nucleus in a southwest direction. The shell has an estimated surface brightness of around 25.7 magnitude per arcsecond. Several other galaxies are found within the field of the host galaxy, suggested to be interacting with it. Radio imaging made with the Very Large Array (VLA) have shown the source has a complex morphology. The source has both radio lobes and a compact radio core, however there are no signs of a radio jet. An image made by the Chandra X-ray Observatory showed there is also radio emission extended and surrounding the base of its northern radio lobe. A bright region is found in the northern radio lobe in addition. There are more detections of radio emission in the galaxy's other regions and hot spot features.

References

External links PKS 0442−28 on SIMBAD

Illustrations

Worked examples

Example 1 — a first encounter with PKS 0442−28

Start with the simplest possible case. Write down what PKS 0442−28 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 PKS 0442−28 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 PKS 0442−28 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 PKS 0442−28

In research: PKS 0442−28 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 PKS 0442−28 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: PKS 0442−28 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Active galaxies, Astronomical objects discovered in 1965, Elliptical galaxies, so understanding it makes those chapters shorter.
In everyday life: Look for PKS 0442−28 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 PKS 0442−28 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what PKS 0442−28 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 PKS 0442−28 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is PKS 0442−28 in simple terms?

Why does PKS 0442−28 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 PKS 0442−28?

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 PKS 0442−28.