M82 X-2
M82 X-2 is an X-ray pulsar located in the galaxy Messier 82, approximately 12 million light-years from Earth. It is exceptionally luminous, radiating energy equivalent to approximately ten million Suns. This object is part of a binary system: If the pulsar is of an average size, 1.4 M☉, then its companion is at least 5.2 M☉. On average, the pulsar rotates every 1.37 seconds, and revolves around its more massive companion every 2.5 days.
M82 X-2 is an ultraluminous X-ray source (ULX), shining about 100 times brighter than theory suggests something of its mass should be able to. Its brightness is many times higher than the Eddington limit, a basic physics guideline that sets an upper limit on the brightness that an object of a given mass should be able to achieve. Possible explanations for violations of the Eddington limit include geometrical effects arising from the funneling of in-falling material along magnetic field lines.
While M82 X-2 was previously known as an X-ray source, it was not until an observation campaign to study the newly discovered supernova SN 2014J in January 2014 that X-2's true nature was uncovered. Scientists looking at data from the NuSTAR spacecraft noticed a pulsing in the X-ray spectrum coming from near the supernova in Messier 82. Data from the Chandra and Swift spacecraft was used to verify the NuSTAR findings and provide the necessary spatial resolution to determine the exact source. After combining the NuSTAR and Chandra data, scientists were able to discern that M82 X-2 emitted both an X-ray beam and continuous broad X-ray radiation.
X2
X2 may refer to:
Mathematics
Films
Video games
Transport
X2 (film)
X2 (often promoted as X2: X-Men United, or internationally as X-Men 2) is a 2003 American superhero film, based on the X-Men superhero team appearing in Marvel Comics, distributed by 20th Century Fox. It is the sequel to 2000's X-Men and the second installment in the X-Men film series. The film was directed by Bryan Singer, written by Michael Dougherty, Dan Harris, and David Hayter, and features an ensemble cast including Patrick Stewart, Hugh Jackman, Ian McKellen, Halle Berry, Famke Janssen, James Marsden, Rebecca Romijn-Stamos, Brian Cox, Alan Cumming, Bruce Davison, Shawn Ashmore, Aaron Stanford, Kelly Hu, and Anna Paquin. The plot, inspired by the graphic novel God Loves, Man Kills, pits the X-Men and their enemies, the Brotherhood, against the genocidal Colonel William Stryker (Brian Cox). He leads an assault on Professor Xavier's school to build his own version of Xavier's mutant-tracking computer Cerebro, in order to destroy every mutant on Earth.
Development on X2 began shortly after X-Men (2000). David Hayter and Zak Penn wrote separate scripts, combining what they felt to be the best elements of both scripts into one screenplay. Michael Dougherty and Dan Harris were eventually hired to rewrite the work, and changed the characterizations of Beast, Angel, and Lady Deathstrike. Sentinels and the Danger Room were set to appear before being deleted because of budget concerns. Filming began in June 2002 and ended that November. Most of the filming took place at Vancouver Film Studios, the largest North American production facility outside of Los Angeles. Production designer Guy Hendrix Dyas adapted similar designs by John Myhre from the previous film.
Square (algebra)
In mathematics, a square is the result of multiplying a number by itself. The verb "to square" is used to denote this operation. Squaring is the same as raising to the power 2, and is denoted by a superscript 2; for instance, the square of 3 may be written as 32, which is the number 9. In some cases when superscripts are not available, as for instance in programming languages or plain text files, the notations x^2 or x**2 may be used in place of x2.
The adjective which corresponds to squaring is quadratic.
The square of an integer may also be called a square number or a perfect square. In algebra, the operation of squaring is often generalized to polynomials, other expressions, or values in systems of mathematical values other than the numbers. For instance, the square of the linear polynomial x + 1 is the quadratic polynomial x2 + 2x + 1.
One of the important properties of squaring, for numbers as well as in many other mathematical systems, is that (for all numbers x), the square of x is the same as the square of its additive inverse −x. That is, the square function satisfies the identity x2 = (−x)2. This can also be expressed by saying that the squaring function is an even function.
Podcasts:
