astronomy

PMN J0948+0022

PMN J0948+0022 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 PMN J0948+0022 rather than just read about it. In short: PMN J0948+0022 is a narrow-line Seyfert 1 galaxy and quasar located 5.7 billion light years away in the constellation of Sextans. It has a redshift of (z) 0.5846, and is classified as radio-loud with a flat and inverted radio spectrum.

Key takeaways

PMN J0948+0022 belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect PMN J0948+0022 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of PMN J0948+0022 from memory before moving on to harder problems.

Reference excerpt

PMN J0948+0022 is a narrow-line Seyfert 1 galaxy and quasar located 5.7 billion light years away in the constellation of Sextans. It has a redshift of (z) 0.5846, and is classified as radio-loud with a flat and inverted radio spectrum. First discovered in 2002 in the SDSS survey, this object is known to emit gamma-rays, and as such belongs to a new classification of gamma-ray emitting active galactic nuclei along with 1H 0323+342, PKS 2004-447 and PKS 1502+036.

Description PMN J0948+0022 is constantly in an active state, in terms of emitting gamma-rays. A high energy outburst in July 2010 was detected by the Large Area Telescope aboard the Fermi Gamma-ray Space Telescope. Two flares were detected during observations in 2011. A new gramma-ray flare was emitted by the object on January 1, 2013 when a peak flux was detected in the 0.1-100 GeV energy range, reaching (155 ± 31) × 10−8 ph cm−2 s−1 making it the most powerful then observed. A quasi-simultaneous flare was observed on December 30, 2012, detected in ultraviolet, optical and X-rays. In 2025 it displayed a radio flare. The radio structure of PMN J0948+0022 is extended on kiloparsec-scales. Radio imaging made by FIRST showed there are two components, located north and south, clearly elongated on two sides and centered at the location of the radio core. There is a powerful relativistic jet pointing in the direction of Earth. This jet's viewing angle is constantly fixed to 3°, while on parsec-scales the jet has an opening angle of 41° ± 1°. The Very Long Baseline Array found strong and weak components in PMN J0948+0022 at 15, 5 and 8.4 GHz, while a single component was only found unresolved by the Very Large Array (VLA). In 2019 new radio imaging by the VLA detected a new northern component located 18° from the nucleus. This component is compact, with a separation of 9.1 arcseconds and is elongated in a different direction. Polarimetry data taken with the Perkins Telescope at Lowell Observatory discovered PMN J0948+0022 displays both optical polarization and rapid microvariability, suggesting blazar-like behavior. Moderate but significant variability was detected in addition, with the percentage of polarization reaching 12.31% ± 1.21% and the electric vector position angle varies. On short timescales PMN J048+0022 was also extremely variable with its minimum brightness increasing from 18.69 ± 0.02 R to a maximum brightness of 17.92 ± 0.02 R within 4 hours and 45 minutes. Subsequently its brightness declined rapidly from 18.13 ± 0.04 R to 18.96 ± 0.02 R in 3 hours. The timescale doubled to 4.39 ± 0.19 hr, then halved to 3.60 ± 0.23 hr. PMN J0948+0022 also displays intraday variability. On April 26, 2020 it entered a new intraday variability phase detected by the Wide-field Infrared Survey Explorer. During the observations, the source begin to fade over a one day period, to the point it became darkened. According to linear fits on both light curves, a magnitude change was calculated as 0.73 and 0.62 magnitude per day. The central supermassive black hole in PMN J0948+0022 has an estimated mass of 1.61 × 107 M☉ based on a radius-luminosity relationship proposed by Du and Wang in 2019. The accretion rate is Ṁ = 93 and combined with its black hole mass, this confirms PMN J0948+0022 as a super-Eddington accreting galaxy located at a high redshift.

References

External links PMN J0948+022 on SIMBAD

Illustrations

Worked examples

Example 1 — a first encounter with PMN J0948+0022

Start with the simplest possible case. Write down what PMN J0948+0022 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 PMN J0948+0022 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 PMN J0948+0022 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 PMN J0948+0022

In research: PMN J0948+0022 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 PMN J0948+0022 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: PMN J0948+0022 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Active galaxies, Astronomical objects discovered in 2002, Quasars, so understanding it makes those chapters shorter.
In everyday life: Look for PMN J0948+0022 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 PMN J0948+0022 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what PMN J0948+0022 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.
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Frequently asked questions

What is PMN J0948+0022 in simple terms?

Why does PMN J0948+0022 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 PMN J0948+0022?

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 PMN J0948+0022.