astronomy

PKS 0458−020

PKS 0458−020 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 0458−020 rather than just read about it. In short: PKS 0458−020 also known as PKS 0458−02, is a quasar located in the constellation of Orion. It has a redshift of (z) 2.286 and was first identified as an astronomical radio source during the radio survey conducted by Parkes Observatory in 1966.

Key takeaways

PKS 0458−020 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 0458−020 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of PKS 0458−020 from memory before moving on to harder problems.

Reference excerpt

PKS 0458−020 also known as PKS 0458−02, is a quasar located in the constellation of Orion. It has a redshift of (z) 2.286 and was first identified as an astronomical radio source during the radio survey conducted by Parkes Observatory in 1966. Subsequently the source was shown to display optical behavior before being classified as a blazar via an optical polarimetry study in 1985. This source also shows radio spectrum appearing to be flat, hence making it a flat-spectrum radio quasar (FRSQ).

Description PKS 0458−020 is found variable across the electromagnetic spectrum and a source of gamma ray activity. It is known to show optical flares which was detected by Fermi Gamma-ray Space Telescope (Fermi LAT) and by the Nordic Optical Telescope in September 2012, where it was reported to be 30 times brighter than its daily flux of (E > 100 MeV) when recorded by Fermi LAT. A near infrared flare was detected in January 2015. The radio structure of PKS 0458−020 is extended across a wide scale range. Radio images of the object produced via Very Large Array (VLA), showed two unique components separated by 1.8 arcseconds with a position angle of -127°. A jet can be seen heading northwest before veering southwest. This jet also appears to have a sharp bend by around 60° based on 15 and 43 GHz imaging. There is a strong compact radio core straddled by extended emission which yields a projected angular size of 3.5 arcseconds. A secondary structure is located southwest from the core with a bridge-like structure almost connecting it. There is also some lobe luminosity located on the side of the counterjet with the jet's side having halo emission. The supermassive black hole in PKS 0458−020 is estimated to be 8 × 108 M☉ based on an Ld value corresponding to the peaking of a disk spectrum with the disk luminosity being Ld ~ 2 × 1046 erg s−1. Two absorption line systems located at redshifts (z) 2.039 and (z) 2.04 were detected towards the object with the former having the largest known redshift at radio wavelengths.

References

External links PKS 0458−020 on SIMBAD PKS 0458−02 on NASA/IPAC Database

Illustrations

Worked examples

Example 1 — a first encounter with PKS 0458−020

Start with the simplest possible case. Write down what PKS 0458−020 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 0458−020 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 0458−020 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 0458−020

In research: PKS 0458−020 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 0458−020 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 0458−020 is common in secondary-school and first-year university syllabi. It links to neighbouring topics 4C objects, Active galaxies, Astronomical objects discovered in 1966, so understanding it makes those chapters shorter.
In everyday life: Look for PKS 0458−020 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 0458−020 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what PKS 0458−020 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 0458−020 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is PKS 0458−020 in simple terms?

Why does PKS 0458−020 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 0458−020?

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 0458−020.