astronomy

TON S180

TON S180 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 TON S180 rather than just read about it. In short: TON S180 (abbreviation of Tonantzintla S180) is a Seyfert galaxy located in the southern constellation of Cetus. It is located 827 million light years from Earth.

Key takeaways

TON S180 belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect TON S180 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of TON S180 from memory before moving on to harder problems.

Reference excerpt

TON S180 (abbreviation of Tonantzintla S180) is a Seyfert galaxy located in the southern constellation of Cetus. It is located 827 million light years from Earth. The galaxy is classified as a quasi-stellar object (QSO) because of its high luminosity and is located 3.6 degrees northeast from NGC 253, and 2.8 degrees southeast from NGC 247.

Discovery and observation TON S180 was first discovered in the year 1958 by Mexican astronomers who catalogued the object as entry number 180 under the Tonantzintla Blue Stellar Object Survey. In 1962 the object was then catalogued as PHL 912 by the Palomar-Haro-Luyten Survey. Subsequently, in 1980 and 1995, TON S180 was detected as an ultraviolet emitter by the Kiso Schmidt Camera Survey and the Extreme Ultraviolet Explorer.

Characteristics TON S180 is categorized a narrow-line Seyfert galaxy. It has a prototype 'bare' active galactic nucleus with a total infrared luminosity of Lbol ~ 5 × 1045 erg s−1, but no traces of absorption. The galaxy has a vertical soft X-ray spectrum measuring a photon index of Γ = 2.68 and a Hβ width measuring 900 km s−1. In addition, TON S180 has a short galactic column density along the line of sight, approximately NH = 1.52 × 1020 cm−2. It has an absolute magnitude of MB = -23.1 and an estimated central black hole mass of M ~ 2 × 107 MΘ. According to a spectral energy distribution presented for TON S180, it is shown more energy is emitted in the 10-100 eV band. The host galaxy of TON S180 is a spiral galaxy of type SABa classification. The galaxy appears as a star-like object found obscured by its own circular halo. It contains a sharp and narrow iron line, as well as having a smooth soft excess unable to be produced by relativistic reflection based on observations of its X-ray spectrum. TON S180 is known to be extremely variable compared to other Seyfert galaxies. Every few thousand seconds, its X-ray flux would show a factor of 2 variability, which, comparing to both the 0.5-2 and 2-10 keV bands, the former has a significantly high σ 2 root mean square. According to the Far Ultraviolet Spectroscopic Explorer, which acquired a high-resolution spectra for the galaxy, TON S180 shows ultraviolet absorption by five-times ionized oxygen but no hydrogen absorption, indicating its absorbing gas is currently in a high ionization state.

References

Illustrations

Worked examples

Example 1 — a first encounter with TON S180

Start with the simplest possible case. Write down what TON S180 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 TON S180 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 TON S180 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 TON S180

In research: TON S180 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 TON S180 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: TON S180 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Astronomical objects discovered in 1958, Cetus (constellation), IRAS catalogue objects, so understanding it makes those chapters shorter.
In everyday life: Look for TON S180 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 TON S180 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what TON S180 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 TON S180 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is TON S180 in simple terms?

TON S180 (abbreviation of Tonantzintla S180) is a Seyfert galaxy located in the southern constellation of Cetus. It is located 827 million light years from Earth.

Why does TON S180 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 TON S180?

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 TON S180.