science

SDSS J0927+2943

SDSS J0927+2943 is a science 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 SDSS J0927+2943 rather than just read about it. In short: SDSS J0927+2943 (SDSS J092712.65+294344.0) is an unusual quasar. It exhibits two sets of optical emission lines with different redshifts.

Key takeaways

SDSS J0927+2943 belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect SDSS J0927+2943 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of SDSS J0927+2943 from memory before moving on to harder problems.

Reference excerpt

SDSS J0927+2943 (SDSS J092712.65+294344.0) is an unusual quasar. It exhibits two sets of optical emission lines with different redshifts. The origin of the two emission line systems is believed to be a gravitational wave recoil event: the ejection of a supermassive black hole from the center of the host galaxy. In this interpretation, one of the emission line systems originates in gas that is bound to the black hole, while the other set is associated with gas that remains in the galaxy.

Evidence for a recoiling black hole A team led by Stefanie Komossa of the Max Planck Institute for Extraterrestrial Physics carried out the analysis. Two systems of strong emission lines were identified in the optical spectrum of this quasar. The first, or "red", system consists of narrow lines of [O III] and other ionized elements at a redshift of z=0.712. Such lines are normally associated with gas far from the center of a galaxy, which is being excited by emission from the central quasar. The second, or "blue", system consists of broad emission lines, the kind that are generally associated with hot gas very close to the supermassive black hole; these lines are at a redshift of 0.697. The velocity difference between the two emission line systems is 2650 km/s. This puzzling observation is most naturally explained if the black hole was ejected from the nucleus of the galaxy, carrying with it the broad-line gas while leaving behind the bulk of the narrow-line gas. Such ejection is possible, if the black hole formed recently from the merger of two, smaller black holes. The merger is accompanied by the emission of gravitational waves, which can be emitted anisotropically, imparting linear momentum to the merger remnant - in effect, "kicking" the black hole out of the galaxy. This discovery is important because it indirectly proves that black holes merge and that the mergers can be accompanied by large kicks. This process had been postulated by theory, but never before confirmed via direct observation.

Illustrations

Worked examples

Example 1 — a first encounter with SDSS J0927+2943

Start with the simplest possible case. Write down what SDSS J0927+2943 claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, 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 SDSS J0927+2943 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 SDSS J0927+2943 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 SDSS J0927+2943

In research: SDSS J0927+2943 appears in science 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 SDSS J0927+2943 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: SDSS J0927+2943 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Leo (constellation), Quasars, SDSS objects, so understanding it makes those chapters shorter.
In everyday life: Look for SDSS J0927+2943 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 “SDSS J0927+2943” →

Affiliate

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

How to study SDSS J0927+2943 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what SDSS J0927+2943 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 SDSS J0927+2943 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is SDSS J0927+2943 in simple terms?

SDSS J0927+2943 (SDSS J092712.65+294344.0) is an unusual quasar. It exhibits two sets of optical emission lines with different redshifts.

Why does SDSS J0927+2943 matter?

Because it connects several science 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 SDSS J0927+2943?

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 SDSS J0927+2943.