astronomy

PG 1011−040

PG 1011−040 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 PG 1011−040 rather than just read about it. In short: PG 1011−040 is a Seyfert type 1 galaxy and a radio-quiet quasar located in the constellation of Sextans. The redshift of the galaxy is (z) 0.058 and it was first discovered by astronomers in June 1983 who were conducting the Palomar Quasar Survey (PG).

Key takeaways

PG 1011−040 belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect PG 1011−040 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of PG 1011−040 from memory before moving on to harder problems.

Reference excerpt

PG 1011−040 is a Seyfert type 1 galaxy and a radio-quiet quasar located in the constellation of Sextans. The redshift of the galaxy is (z) 0.058 and it was first discovered by astronomers in June 1983 who were conducting the Palomar Quasar Survey (PG).

Description PG 1011−040 is categorized as a narrow-line Seyfert galaxy with weak X-ray source and a total luminosity of 6.3 × 1041 erg s−1. Its host is classified to be a barred spiral galaxy of type SBb with a disk appearance, peculiar inner ring structures and presence of spiral arms. The supermassive black hole mass of the galaxy is estimated to be 7.43 M☉ and the total star formation rate of the galaxy is 4.82 M☉ per year. The stellar mass of the galaxy is estimated to be 10.31 M☉. The radio source is found compact. When imaged with Very Large Array (VLA), it appears to show a marginal elongation towards the direction of northwest with a presence of a radio core containing a flat radio spectrum. There are also weak extensions shown, hinting either radio emission from the lobes or even a jet on sub-arcsecond scales. A slightly extended structure is found based on radio imaging made by VLA with the total flux density of 0.38 mJy. There is also a bit of extended bipolar emission in mainly the southwest and northeast sides made by hinting the active galactic nucleus of PG 1011−040 is responsible for the emission production. A study published in 2021, found PG 1011−040 has presence of molecular gas. When observed, its carbon monoxide morphology is split into a simple bulge component which in turn, is surrounded by a clumpy structure that is ring-like in appearance. A study in August 2022, has found five star-forming regions mainly located within its ring structure with a stellar bar feature shown penetrating through its nuclear region from the ring structure.

References

External links

PG 1011−040 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images PG 1011−040 on SIMBAD

Illustrations

Worked examples

Example 1 — a first encounter with PG 1011−040

Start with the simplest possible case. Write down what PG 1011−040 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 PG 1011−040 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 PG 1011−040 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 PG 1011−040

In research: PG 1011−040 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 PG 1011−040 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: PG 1011−040 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Active galaxies, Astronomical objects discovered in 1983, Barred spiral galaxies, so understanding it makes those chapters shorter.
In everyday life: Look for PG 1011−040 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 PG 1011−040 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what PG 1011−040 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 PG 1011−040 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is PG 1011−040 in simple terms?

Why does PG 1011−040 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 PG 1011−040?

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 PG 1011−040.