astronomy

NGC 7130

NGC 7130 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 NGC 7130 rather than just read about it. In short: NGC 7130 (also known as IC 5135) is a spiral galaxy located in the constellation Piscis Austrinus. It is located at a distance of about 220 million light years from Earth, which, given its apparent dimensions, means that NGC 7130 is about 188,000 light years across.

Key takeaways

NGC 7130 belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect NGC 7130 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of NGC 7130 from memory before moving on to harder problems.

Reference excerpt

NGC 7130 (also known as IC 5135) is a spiral galaxy located in the constellation Piscis Austrinus. It is located at a distance of about 220 million light years from Earth, which, given its apparent dimensions, means that NGC 7130 is about 188,000 light years across. It was discovered by John Herschel on September 25, 1834, and discovered independently by Lewis Swift on September 17, 1897. The location of the galaxy given in the New General Catalogue was off by 30 arcminutes in declination from the location of the galaxy.

Characteristics NGC 7130 is characterised as a peculiar galaxy based on its distorted shape. The galaxy has two faint arms towards the south, while north of the galaxy there is diffuse H-alpha emission. Two knots with H-alpha emission are observed southeast of the galaxy. The galaxy has star streams and trailing tidal arms. It has been suggested that the distorted shape of NGC 7130 is the result of the interaction with another galaxy. In the infrared K-band a bar is visible. The total infrared luminosity of NGC 7130 is 2.2×1011 L☉ (1011.35 L☉) and it is categorised as a luminous infrared galaxy.

Nucleus NGC 7130 has a bright nucleus which is characterised as active. The galaxy features optical emission lines typical of a type 2 Seyfert galaxy, with broad lines and strong emission lines from high ionisation elements, like [He II], however the ultraviolet spectrum is more consistent with the emission produced by young, massive O-type stars, suggesting an active starburst in the nucleus. More detailed observations in ultraviolet reveal an asymmetric circumnuclear starburst ring with several knots. The total span of the ring is one arcsecond, which corresponds to 310 pc, in the north–south direction, and 0.7 arcseconds, which corresponds to 220 pc, in east–west direction. Ultraviolet emission is also observed at the inner part of the spiral arms at the leading edge of the bar. The galaxy emits also X-rays. Based on observations by Chandra X-ray Observatory it was found that the two thirds of the X-ray emission at 0.3–8 keV of the galaxy comes from the circumnuclear starburst activity and the galaxy disk, while the rest was attributed to an active galactic nucleus (AGN) hidden by a Compton-thick column with column density over 1024 cm−2. The percentage attributed to the AGN exceeds 50% at higher energies, over 2 keV. The transition from the emission of the AGN to that of the starburst is smooth, as seen by the different ionisation states of the gas around the nucleus. The extended narrow-line region of NGC 7130 is estimated to have a radius of 1.8±0.8 kpc. There is also an outflowing wind, whose origin however cannot be determined accurately. In the centre of NGC 7130 lies a supermassive black hole whose mass is estimated to be 3.9×107 M☉ (107.59 M☉) based on stellar velocity dispersion. The star formation rate in the central kiloparsec of NGC 7130 is estimated to be 4.3 M☉ per year. The total star formation rate of the galaxy is estimated to be 21 M☉ per year.

Supernovae Two supernovae have been observed in NGC 7130:

SN 2010bt (Type IIn, mag 15.9) was discovered by Berto Monard on 17 April 2010. SN 2017hgz (Type Ia, mag 15.1) was discovered by ASAS-SN on 10 October 2017.

Nearby galaxies NGC 7130 belongs in a galaxy group known as LGG 445. Other members of the galaxy group include NGC 7057, IC 5105, NGC 7087, NGC 7060, NGC 7072, NGC 7075, NGC 7110, IC 5128, and IC 5139. Near NGC 7130 lie also the distorted NGC 7135, 18 arcminutes to the east, and IC 5131, 12 arcminutes to the west. It has been suggested that the distortion of NGC 7130 was caused by an interaction with one of these two galaxies, however, they have nearly half the redshift.

See also NGC 7679 - A similar starburst and active galaxy

References

External links

NGC 7130 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images NGC 7130 on SIMBAD

Illustrations

Worked examples

Example 1 — a first encounter with NGC 7130

Start with the simplest possible case. Write down what NGC 7130 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 NGC 7130 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 NGC 7130 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 NGC 7130

In research: NGC 7130 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 NGC 7130 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: NGC 7130 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Astronomical objects discovered in 1834, Discoveries by John Herschel, ESO objects, so understanding it makes those chapters shorter.
In everyday life: Look for NGC 7130 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 NGC 7130 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what NGC 7130 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 NGC 7130 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is NGC 7130 in simple terms?

Why does NGC 7130 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 NGC 7130?

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 NGC 7130.