astronomy

PKS 2145+067

PKS 2145+067 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 2145+067 rather than just read about it. In short: PKS 2145+067 is a radio-loud quasar located in the constellation of Pegasus. It has a redshift of (z) 1.003 and it was first discovered by astronomers conducting the Parkes Survey at Parkes Observatory in 1966, designated as PKS 2145+06.

Key takeaways

PKS 2145+067 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 2145+067 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of PKS 2145+067 from memory before moving on to harder problems.

Reference excerpt

PKS 2145+067 is a radio-loud quasar located in the constellation of Pegasus. It has a redshift of (z) 1.003 and it was first discovered by astronomers conducting the Parkes Survey at Parkes Observatory in 1966, designated as PKS 2145+06. The radio spectrum of the object is flat, making it a flat-spectrum source, but it is classified as a weakly polarized quasar.

Description PKS 2145+067 is classified as a blazar mainly due to its variability on the electromagnetic spectrum, displaying four flares when observed at eight frequency bands between 4.8 and 230 GHz frequencies, and radio flux variations that reaching 2 Jy within 2 hours. In additional to its flaring activity, it also had weak intensity fluctuations resulting from interstellar scintillation in daily averages of 2695 and 8086 MHz. The X-ray flux of the quasar is known to vary, from 3.3 × 10−12 erg cm−2 s−1 at 0.1 and 2.0 KeV in May 1991 to 3.8 × 10−12 erg cm−2 s−1 in 1994. The radio structure of PKS 2145+067 is compact. When observed with Very Long Baseline Interferometry (VLBI), the radio core is shown as weakly elongated with no signs of a significant structure. At 5 GHz, it has a strong elongated component towards the south-east direction and another component found diffused with a position angle of 140°. These two components are found embedded in a diffused halo. VLBI Observations at 93 centimeters showed the source has some possible structural features that are located 48 and 200 milliarcseconds from the core and a single component roughly containing 30% of its flux density. Geodetic VLBI imaging revealed the object's core has a size of 0.25 milliarcseconds in extent and a brightness temperature of 1.4 × 1012 Kelvin, with extended radio emission orientating at 140°. The jet of PKS 2145+067 is known to be compact. When observed by Flávio Benevenuto da Silva Junior and Anderson Caproni, the jet was made up of 11 components which are moving at superluminal velocities with speeds between 10c and 18c. The position angles of these components are all estimated between the ranges of 0.03 and 11.29 degrees. PKS 2145+067 is classified as a Lyman-limit quasar with a detected Lyman-limit system located at the redshift of (z) 0.7913, accompanying several metal-rich absorption lines in various states of low and high ionization. X-ray observations by the Advanced Satellite for Cosmology and Astrophysics (ASCA) also showed the quasar has a 0.6-10 KeV spectrum of 1.3 × 10−11 erg cm−2 s-1, best fitted by a power-law model. The host galaxy of PKS 2145+067 is marginally resolved by near-infrared H-band imaging.

References

External links PKS 2145+067 on SIMBAD

Illustrations

Worked examples

Example 1 — a first encounter with PKS 2145+067

Start with the simplest possible case. Write down what PKS 2145+067 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 2145+067 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 2145+067 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 2145+067

In research: PKS 2145+067 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 2145+067 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 2145+067 is common in secondary-school and first-year university syllabi. It links to neighbouring topics 4C objects, Active galaxies, Astronomical objects discovered in 1966, so understanding it makes those chapters shorter.
In everyday life: Look for PKS 2145+067 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 PKS 2145+067 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what PKS 2145+067 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 2145+067 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is PKS 2145+067 in simple terms?

Why does PKS 2145+067 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 2145+067?

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 2145+067.