astronomy

PKS 2215+020

PKS 2215+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 2215+020 rather than just read about it. In short: PKS 2215+020, known as PMN J2217+0220, is a quasar located in the Aquarius constellation. Its redshift is 3.57, meaning the object is located 11.6 billion light-years away from Earth.

Key takeaways

PKS 2215+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 2215+020 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of PKS 2215+020 from memory before moving on to harder problems.

Reference excerpt

PKS 2215+020, known as PMN J2217+0220, is a quasar located in the Aquarius constellation. Its redshift is 3.57, meaning the object is located 11.6 billion light-years away from Earth. It is classified as a flat-spectrum radio quasar.

Characteristics PKS 2215+020 is an optically faint and radio-loud quasar (S5 GHz = 0.50.6 Jy). Included as part of the Parkes Half-Jansky Flat Spectrum Sample, the quasar has a corresponding linear scale of 3.38 h−1 pc mas−1 and deceleration parameter of q0 = 0.5, which its radio spectral index of 2215+020 is a 5 GHz divided by 2.7 GHz = -0.15 (Sv ∞ vx). From X-ray emission observation with ROSAT in 1998, a minimum evidence for possible elongation along the P.A. = 60°-70° is found. PKS 2215+020 is a blazar, a type of active galaxy shooting out a jet towards the direction of Earth, according to researchers who studied its jet components. They found out that the quasar contains a nearly proper motion (0.02 mas/yr) superluminal jet about two times the speed of light. PKS 2215+020 has a delta of =11.5 for the Doppler-boosting factor, which they found that the inner relativistic jet inclined within 2 degrees to line of sight, with a Lorentz factor of Gamma=6 bulk. Further observations from the VSOP observation, found out the jet in PKS 2215+020 has an interesting morphology. They observed that extent of the jet is remarkable showing >80 mas, 250 h−1 pc. Moreover, the jet structures observed in 2215+020 are 10 time larger compared to quasars at z > 3 observed with VLBI, suggesting the jet has a working surface.

Black hole The supermassive black hole in the center of PKS 2215+020 has an estimated 4 billion solar masses (M☉). According to resolution images of the quasar, researchers found there is rich core-jet structure, unusually large, based on the linear scales from 5 h−1 to 300 h−1 pc (H0 = 100 h km s-1 Mpc-1). This makes PKS 2215+020 to have the longest jet observed, so far at a redshift greater than 3. Through comparing similarities with the VLA and ROSAT observations, an extended radio/X-ray halo surrounding PKS 2215+020 is present.

References

Illustrations

Worked examples

Example 1 — a first encounter with PKS 2215+020

Start with the simplest possible case. Write down what PKS 2215+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 2215+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 2215+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 2215+020

In research: PKS 2215+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 2215+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 2215+020 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Active galaxies, Aquarius (constellation), Blazars, so understanding it makes those chapters shorter.
In everyday life: Look for PKS 2215+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.

Ask Teacher Smith questions about this articleOpens your AI tutor with a question about “PKS 2215+020” →

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study PKS 2215+020 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what PKS 2215+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 2215+020 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is PKS 2215+020 in simple terms?

PKS 2215+020, known as PMN J2217+0220, is a quasar located in the Aquarius constellation. Its redshift is 3.57, meaning the object is located 11.6 billion light-years away from Earth.

Why does PKS 2215+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 2215+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 2215+020.