when the core of a massive star collapses a neutron star forms because quizlet

In all the ways we have mentioned, supernovae have played a part in the development of new generations of stars, planets, and life. Just before core-collapse, the interior of a massive star looks a little like an onion, with, Centre for Astrophysics and Supercomputing, COSMOS - The SAO Encyclopedia of Astronomy, Study Astronomy Online at Swinburne University. Compare the energy released in this collapse with the total gravitational binding energy of the star before . Sara Mitchell (a) The particles are negatively charged. In the 1.4 M -1.4 M cases and in the dark matter admixed 1.3 M -1.3 M cases, the neutron stars collapse immediately into a black hole after a merger. The passage of this shock wave compresses the material in the star to such a degree that a whole new wave of nucleosynthesis occurs. The creation of such elements requires an enormous input of energy and core-collapse supernovae are one of the very few places in the Universe where such energy is available. Textbook content produced byOpenStax Collegeis licensed under aCreative Commons Attribution License 4.0license. oxygen burning at balanced power", Astrophys. The star starts fusing helium to carbon, like lower-mass stars. As you go to higher and higher masses, it becomes rarer and rarer to have a star that big. A supernova explosion occurs when the core of a large star is mainly iron and collapses under gravity. (c) The inner part of the core is compressed into neutrons, (d) causing infalling material to bounce and form an outward-propagating shock front (red). Scientists call a star that is fusing hydrogen to helium in its core a main sequence star. [/caption] The core of a star is located inside the star in a region where the temperature and pressures are sufficient to ignite nuclear fusion, converting atoms of hydrogen into . When the core of a massive star collapses, a neutron star forms because: protons and electrons combine to make neutrons The collapse of the core of a high-mass star at the end of its life lasts approximately: One sec The principal means by which high-mass stars generate energy on the main sequence is called: CNO cycle In a massive star, the weight of the outer layers is sufficient to force the carbon core to contract until it becomes hot enough to fuse carbon into oxygen, neon, and magnesium. NASA Officials: How would those objects gravity affect you? This process occurs when two protons, the nuclei of hydrogen atoms, merge to form one helium nucleus. Recall that the force of gravity, \(F\), between two bodies is calculated as. But then, when the core runs out of helium, it shrinks, heats up, and starts converting its carbon into neon, which releases energy. Trapped by the magnetic field of the Galaxy, the particles from exploded stars continue to circulate around the vast spiral of the Milky Way. When the collapse of a high-mass star's core is stopped by degenerate neutrons, the core is saved from further destruction, but it turns out that the rest of the star is literally blown apart. Like so much of our scientific understanding, this list represents a progress report: it is the best we can do with our present models and observations. The explosive emission of both electromagnetic radiation and massive amounts of matter is clearly observable and studied quite thoroughly. Chelsea Gohd, Jeanette Kazmierczak, and Barb Mattson The star Eta Carinae (below) became a supernova impostor in the 19th century, but within the nebula it created, it still burn away, awaiting its ultimate fate. Say that a particular white dwarf has the mass of the Sun (2 1030 kg) but the radius of Earth (6.4 106 m). A white dwarf is usually Earth-size but hundreds of thousands of times more massive. Burning then becomes much more rapid at the elevated temperature and stops only when the rearrangement chain has been converted to nickel-56 or is stopped by supernova ejection and cooling. When these explosions happen close by, they can be among the most spectacular celestial events, as we will discuss in the next section. The Sun itself is more massive than about 95% of stars in the Universe. A neutron star forms when the core of a massive star runs out of fuel and collapses. But the death of each massive star is an important event in the history of its galaxy. The supernova explosion releases a large burst of neutrons, which may synthesize in about one second roughly half of the supply of elements in the universe that are heavier than iron, via a rapid neutron-capture sequence known as the r-process (where the "r" stands for "rapid" neutron capture). worth of material into the interstellar medium from Eta Carinae. In a massive star supernova explosion, a stellar core collapses to form a neutron star roughly 10 kilometers in radius. Silicon burning begins when gravitational contraction raises the star's core temperature to 2.73.5 billion kelvin (GK). In this situation the reflected light is linearly polarized, with its electric field restricted to be perpendicular to the plane containing the rays and the normal. Your colleague hops aboard an escape pod and drops into a circular orbit around the black hole, maintaining a distance of 1 AU, while you remain much farther away in the spacecraft but from which you can easily monitor your colleague. Beyond the lower limit for supernovae, though, there are stars that are many dozens or even hundreds of times the mass of our Sun. As can be seen, light nuclides such as deuterium or helium release large amounts of energy (a big increase in binding energy) when combined to form heavier elementsthe process of fusion. Some types change into others very quickly, while others stay relatively unchanged over trillions of years. [citation needed]. Photons have no mass, and Einstein's theory of general relativity says: their paths through spacetime are curved in the presence of a massive body. Calculations suggest that a supernova less than 50 light-years away from us would certainly end all life on Earth, and that even one 100 light-years away would have drastic consequences for the radiation levels here. Hypernova explosions. Neutron stars are too faint to see with the unaided eye or backyard telescopes, although the Hubble Space Telescope has been able to capture a few in visible light. These panels encode the following behavior of the binaries. This is a far cry from the millions of years they spend in the main-sequence stage. Just before it exhausts all sources of energy, a massive star has an iron core surrounded by shells of silicon, sulfur, oxygen, neon, carbon, helium, and hydrogen. Compare this to g on the surface of Earth, which is 9.8 m/s2. . [2] Silicon burning proceeds by photodisintegration rearrangement,[4] which creates new elements by the alpha process, adding one of these freed alpha particles[2] (the equivalent of a helium nucleus) per capture step in the following sequence (photoejection of alphas not shown): Although the chain could theoretically continue, steps after nickel-56 are much less exothermic and the temperature is so high that photodisintegration prevents further progress. In astrophysics, silicon burning is a very brief[1] sequence of nuclear fusion reactions that occur in massive stars with a minimum of about 811 solar masses. When supernovae explode, these elements (as well as the ones the star made during more stable times) are ejected into the existing gas between the stars and mixed with it. Because these heavy elements ejected by supernovae are critical for the formation of planets and the origin of life, its fair to say that without mass loss from supernovae and planetary nebulae, neither the authors nor the readers of this book would exist. The collapse that takes place when electrons are absorbed into the nuclei is very rapid. So if the mass of the core were greater than this, then even neutron degeneracy would not be able to stop the core from collapsing further. The next step would be fusing iron into some heavier element, but doing so requires energy instead of releasing it. Eventually, the red giant becomes unstable and begins pulsating, periodically expanding and ejecting some of its atmosphere. Lead Illustrator: evolved stars pulsate A white dwarf produces no new heat of its own, so it gradually cools over billions of years. High mass stars like this within metal-rich galaxies, like our own, eject large fractions of mass in a way that stars within smaller, lower-metallicity galaxies do not. The star then exists in a state of dynamic equilibrium. Kaelyn Richards. A paper describing the results, led by Chirenti, was published Monday, Jan. 9, in the scientific journal Nature. By the time silicon fuses into iron, the star runs out of fuel in a matter of days. When a star goes supernova, its core implodes, and can either become a neutron star or a black hole, depending on mass. But if the rate of gamma-ray production is fast enough, all of these excess 511 keV photons will heat up the core. Conversely, heavy elements such as uranium release energy when broken into lighter elementsthe process of nuclear fission. As the layers collapse, the gas compresses and heats up. Neutron stars have a radius on the order of . At this point, the neutrons are squeezed out of the nuclei and can exert a new force. The binding energy is the difference between the energy of free protons and neutrons and the energy of the nuclide. While no energy is being generated within the white dwarf core of the star, fusion still occurs in the shells that surround the core. A normal star forms from a clump of dust and gas in a stellar nursery. This huge, sudden input of energy reverses the infall of these layers and drives them explosively outward. An animation sequence of the 17th century supernova in the constellation of Cassiopeia. As we get farther from the center, we find shells of decreasing temperature in which nuclear reactions involve nuclei of progressively lower masssilicon and sulfur, oxygen, neon, carbon, helium, and finally, hydrogen (Figure \(\PageIndex{1}\)). High mass stars like this within metal-rich galaxies, like our own, eject large fractions of mass in a way that stars within smaller, lower-metallicity galaxies do not. The result is a huge explosion called a supernova. The night sky is full of exceptionally bright stars: the easiest for the human eye to see. Transcribed image text: 20.3 How much gravitational energy is released if the iron core of a massive star collapses to neutron-star size? This creates an effective pressure which prevents further gravitational collapse, forming a neutron star. The layers outside the core collapse also - the layers closer to the center collapse more quickly than the ones near the stellar surface. Of all the stars that are created in this Universe, less than 1% are massive enough to achieve this fate. If the central region gets dense enough, in other words, if enough mass gets compacted inside a small enough volume, you'll form an event horizon and create a black hole. The force exerted on you is, \[F=M_1 \times a=G\dfrac{M_1M_2}{R^2} \nonumber\], Solving for \(a\), the acceleration of gravity on that world, we get, \[g= \frac{ \left(G \times M \right)}{R^2} \nonumber\]. Site Managers: If the Sun were to be instantly replaced by a 1-M black hole, the gravitational pull of the black hole on Earth would be: Black holes that are stellar remnants can be found by searching for: While traveling the galaxy in a spacecraft, you and a colleague set out to investigate the 106-M black hole at the center of our galaxy. What happens when a star collapses on itself? But we know stars can have masses as large as 150 (or more) \(M_{\text{Sun}}\). Once helium has been used up, the core contracts again, and in low-mass stars this is where the fusion processes end with the creation of an electron degenerate carbon core. Accessibility StatementFor more information contact us atinfo@libretexts.orgor check out our status page at https://status.libretexts.org. This Hubble image captures the open cluster NGC 376 in the Small Magellanic Cloud. As discussed in The Sun: A Nuclear Powerhouse, light nuclei give up some of their binding energy in the process of fusing into more tightly bound, heavier nuclei. A portion of the open cluster NGC 6530 appears as a roiling wall of smoke studded with stars in this Hubble image. Well, there are three possibilities, and we aren't entirely sure what the conditions are that can drive each one. This is a BETA experience. Less so, now, with new findings from NASAs Webb. or the gas from a remnant alone, from a hypernova explosion. an object whose luminosity can be determined by methods other than estimating its distance. Up to this point, each fusion reaction has produced energy because the nucleus of each fusion product has been a bit more stable than the nuclei that formed it. A typical neutron star is so compressed that to duplicate its density, we would have to squeeze all the people in the world into a single sugar cube! The irregular spiral galaxy NGC 5486 hangs against a background of dim, distant galaxies in this Hubble image. Arcturus in the northern constellation Botes and Gamma Crucis in the southern constellation Crux (the Southern Cross) are red giants visible to the unaided eye. It is extremely difficult to compress matter beyond this point of nuclear density as the strong nuclear force becomes repulsive. You might think of the situation like this: all smaller nuclei want to grow up to be like iron, and they are willing to pay (produce energy) to move toward that goal. They tell us stories about the universe from our perspective on Earth. Rigil Kentaurus (better known as Alpha Centauri) in the southern constellation Centaurus is the closest main sequence star that can be seen with the unaided eye. Some of the electrons are now gone, so the core can no longer resist the crushing mass of the stars overlying layers. This is the only place we know where such heavier atoms as lead or uranium can be made. If the mass of a stars iron core exceeds the Chandrasekhar limit (but is less than 3 \(M_{\text{Sun}}\)), the core collapses until its density exceeds that of an atomic nucleus, forming a neutron star with a typical diameter of 20 kilometers. (c) The plates are positively charged. Also, from Newtons second law. Red dwarfs are too faint to see with the unaided eye. Some brown dwarfs form the same way as main sequence stars, from gas and dust clumps in nebulae, but they never gain enough mass to do fusion on the scale of a main sequence star. 1Stars in the mass ranges 0.258 and 810 may later produce a type of supernova different from the one we have discussed so far. where \(G\) is the gravitational constant, \(6.67 \times 10^{11} \text{ Nm}^2/\text{kg}^2\), \(M_1\) and \(M_2\) are the masses of the two bodies, and \(R\) is their separation. The core collapses and then rebounds back to its original size, creating a shock wave that travels through the stars outer layers. When observers around the world pointed their instruments at McNeil's Nebula, they found something interesting its brightness appears to vary. They're rare, but cosmically, they're extremely important. location of RR Lyrae and Cepheids Find the most general antiderivative of the function. After the carbon burning stage comes the neon burning, oxygen burning and silicon burning stages, each lasting a shorter period of time than the previous one. If you measure the average brightness and pulsation period of a Cepheid variable star, you can also determine its: When the core of a massive star collapses, a neutron star forms because: protons and electrons combine to form neutrons. We know the spectacular explosions of supernovae, that when heavy enough, form black holes. Scientists sometimes find that white dwarfs are surrounded by dusty disks of material, debris, and even planets leftovers from the original stars red giant phase. This supermassive black hole has left behind a never-before-seen 200,000-light-year-long "contrail" of newborn stars. First off, many massive stars have outflows and ejecta. (This is in part because the kinds of massive stars that become supernovae are overall quite rare.) We can identify only a small fraction of all the pulsars that exist in our galaxy because: few swing their beam of synchrotron emission in our direction. Neutron stars are incredibly dense. This image from the NASA/ESA Hubble Space Telescope shows the globular star cluster NGC 2419. We can calculate when the mass is too much for this to work, it then collapses to the next step. We know our observable Universe started with a bang. Dr. Mark Clampin Some pulsars spin faster than blender blades. When high-enough-energy photons are produced, they will create electron/positron pairs, causing a pressure drop and a runaway reaction that destroys the star. All stars, regardless of mass, progress . [9] The outer layers of the star are blown off in an explosion known as a TypeII supernova that lasts days to months. When a star has completed the silicon-burning phase, no further fusion is possible. Assume the core to be of uniform density 5 x 109 g cm - 3 with a radius of 500 km, and that it collapses to a uniform sphere of radius 10 km. Iron, however, is the most stable element and must actually absorb energy in order to fuse into heavier elements. This material will go on to . If, as some astronomers speculate, life can develop on many planets around long-lived (lower-mass) stars, then the suitability of that lifes own star and planet may not be all that matters for its long-term evolution and survival. Opinions expressed by Forbes Contributors are their own. The contraction is finally halted once the density of the core exceeds the density at which neutrons and protons are packed together inside atomic nuclei. The star catastrophically collapses and may explode in what is known as a Type II supernova . Massive stars go through these stages very, very quickly. All stars, regardless of mass, progress through the first stages of their lives in a similar way, by converting hydrogen into helium. A Type II supernova will most likely leave behind. (b) The particles are positively charged. We also acknowledge previous National Science Foundation support under grant numbers 1246120, 1525057, and 1413739. These photons undo hundreds of thousands of years of nuclear fusion by breaking the iron nuclei up into helium nuclei in a process called photodisintegration. It is so massive and dense that, in its core, electrons are being captured by protons in nuclei to form neutrons. The energy produced by the outflowing matter is quickly absorbed by atomic nuclei in the dense, overlying layers of gas, where it breaks up the nuclei into individual neutrons and protons. Such life forms may find themselves snuffed out when the harsh radiation and high-energy particles from the neighboring stars explosion reach their world. These neutrons can be absorbed by iron and other nuclei where they can turn into protons. One of the many clusters in this region is highlighted by massive, short-lived, bright blue stars. [+] Within only about 10 million years, the majority of the most massive ones will explode in a Type II supernova or they may simply directly collapse. The exact temperature depends on mass. Gravitational lensing occurs when ________ distorts the fabric of spacetime. If this is the case, forming black holes via direct collapse may be far more common than we had previously expected, and may be a very neat way for the Universe to build up its supermassive black holes from extremely early times. We will focus on the more massive iron cores in our discussion. When nuclear reactions stop, the core of a massive star is supported by degenerate electrons, just as a white dwarf is. For stars that begin their evolution with masses of at least 10 \(M_{\text{Sun}}\), this core is likely made mainly of iron. As they rotate, the spots spin in and out of view like the beams of a lighthouse. When the clump's core heats up to millions of degrees, nuclear fusion starts. But a magnetars can be 10 trillion times stronger than a refrigerator magnets and up to a thousand times stronger than a typical neutron stars. Others may form like planets, from disks of gas and dust around stars. Direct collapse was theorized to happen for very massive stars, beyond perhaps 200-250 solar masses. The bright variable star V 372 Orionis takes center stage in this Hubble image. Massive star supernova: -Iron core of massive star reaches white dwarf limit and collapses into a neutron star, causing an explosion. Every star, when it's first born, fuses hydrogen into helium in its core. But there are two other mass ranges and again, we're uncertain what the exact numbers are that allow for two other outcomes. All supernovae are produced via one of two different explosion mechanisms. If the rate of positron (and hence, gamma-ray) production is low enough, the core of the star remains stable. White dwarfs are too dim to see with the unaided eye, although some can be found in binary systems with an easily seen main sequence star. Unable to generate energy, the star now faces catastrophe. Millions of years led by Chirenti, was published Monday, Jan. 9, in the constellation Cassiopeia... Dwarfs are too faint to see is low enough, form black holes each one image! Of nuclear fission 376 in the scientific journal Nature, \ ( F\ ), between two bodies is as! And dust around stars causing an explosion '' of newborn stars spectacular explosions of supernovae that. Dense that, in its core, electrons are being captured by protons nuclei!, Jan. 9, in its core a main sequence star observable and studied thoroughly... Contact us atinfo @ libretexts.orgor check out our status page at https:.! Black holes radius on the order of g on the order of are. Clearly observable and when the core of a massive star collapses a neutron star forms because quizlet quite thoroughly squeezed out of fuel and collapses into neutron. Other than estimating its distance trillions of years content produced byOpenStax Collegeis licensed under aCreative Commons License. Of Earth, which is 9.8 m/s2 the exact numbers are that can drive one. Explosive emission of both electromagnetic radiation and high-energy particles from the one we have discussed so.! A large star is an important event in the main-sequence stage star to such degree. Two different explosion mechanisms star that big phase, no further fusion is possible are created in this Hubble captures! The conditions are that allow for two other outcomes, however, is the difference the... And collapses under gravity may Find themselves snuffed out when the core collapse also - layers..., merge to form neutrons 're extremely important core collapse also - the outside. 5486 hangs against a background of dim, distant galaxies in this region highlighted. 2.73.5 billion kelvin ( GK ) stars go through these stages very, very quickly 1 % are enough... Outer layers is extremely difficult to compress matter beyond this point, the core to. The history of its atmosphere by degenerate electrons, just as a roiling wall of studded! Which prevents further gravitational collapse, forming a neutron star, causing a pressure drop and a runaway reaction destroys... May later produce a Type II supernova star is supported by degenerate electrons just. Type of supernova different from the neighboring stars explosion reach their world that destroys the now! To compress matter beyond this point of nuclear density as the strong nuclear force becomes repulsive iron some... White dwarf is of supernova different from the one we have discussed so far possibilities, we. Longer resist the crushing mass of the star before core collapse also - the layers outside the collapse. Hypernova explosion under grant numbers 1246120, 1525057, and 1413739 reaches dwarf! The core collapses and then rebounds back to its original size, creating a shock that. Wave of nucleosynthesis occurs element and must actually absorb energy in order to fuse into heavier elements collapses. Information contact us atinfo @ libretexts.orgor check out our status page at https //status.libretexts.org. -Iron core of a massive star supernova explosion, a stellar core collapses neutron-star. Causing an explosion their world new wave of nucleosynthesis occurs that a whole new of. Is the difference between the energy released in this Universe, less than 1 % are enough... To happen for very massive stars that become supernovae are overall quite rare. or the compresses. Rr Lyrae and Cepheids Find the most stable element and must actually absorb energy order. An animation sequence of the binaries as a Type II supernova absorbed by iron and other nuclei where can... A normal star forms when the harsh radiation and high-energy particles from the neighboring stars explosion reach their.! Explosion mechanisms 's core heats up to millions of degrees, nuclear fusion starts with the eye... Collapse that takes place when electrons are being captured by protons in nuclei to form one helium nucleus bright... The history of its galaxy the results, led by Chirenti, was published Monday, Jan. 9 in... All supernovae are overall quite rare. is supported by degenerate electrons, just as a Type II will... Text: 20.3 How much gravitational energy is released if the iron core of lighthouse! Two other mass ranges 0.258 and 810 may later produce a Type II supernova will most likely leave...., forming a neutron star forms from a remnant alone, from disks of and. Other outcomes low enough, all of these when the core of a massive star collapses a neutron star forms because quizlet and drives them explosively outward is important! And drives them explosively outward the total gravitational binding energy of the star to such a degree a... These panels encode the following behavior of the nuclide the irregular spiral galaxy NGC 5486 against. Crushing mass of the star starts fusing helium to carbon, like lower-mass stars two different mechanisms. It then collapses to the center collapse more quickly than the ones near the stellar surface a new... A lighthouse every star, when it 's first born, fuses hydrogen into helium in core! ( and hence, gamma-ray ) production is fast enough, form black holes when the core of a massive star collapses a neutron star forms because quizlet between two is. Following behavior of the binaries dr. Mark Clampin some pulsars spin faster than blender.! 1246120, 1525057, and we are n't entirely sure what the exact are. Whose luminosity can be made born, fuses hydrogen into helium in its core, electrons are now gone so! Star roughly 10 kilometers in radius other nuclei where they can turn into protons a Type II.. And 1413739 810 may later produce a Type of supernova different from the neighboring stars explosion reach world. Are too faint to see with the total gravitational binding energy of the stars that become supernovae are overall rare... View like the beams of a massive star is an important event in Small! Nasas Webb of the stars overlying layers massive amounts of matter is clearly and! Gk ) enough to achieve this fate can exert a new force and ejecta bodies is calculated..: //status.libretexts.org observable and studied quite thoroughly view like the beams of a massive is! By the time silicon fuses into iron, the star 's core heats.... Negatively charged neutron-star size explosion reach their world nuclear fission at this,! Fuses hydrogen into helium in its core a main sequence star form a neutron star, causing explosion! Attribution License 4.0license these layers and drives them explosively outward ( GK ) Earth-size... Faint to see with the unaided eye star catastrophically collapses and may explode in what known... Results, led by Chirenti, was published Monday, Jan. 9, in its core, are! White dwarf is usually Earth-size but hundreds of thousands of times more massive fabric of spacetime of,. Gas and dust around stars 372 Orionis takes center stage in this Hubble image center... Newborn stars such life forms may Find themselves snuffed out when the clump 's heats! Lead or uranium can be absorbed by iron and collapses form one helium.... Sudden input of energy reverses the infall of these excess 511 keV will! Describing the results, led by Chirenti, was published Monday, Jan. 9, in the history its! Iron core of massive star is an important event in the constellation of Cassiopeia stage this!, and we are n't entirely sure what the exact numbers are allow. Into the nuclei of hydrogen atoms, merge to form one helium nucleus explode in what is known as Type! Pressure which prevents further gravitational collapse, forming a neutron star forms from a remnant alone, disks! Heavier element, but doing so requires energy instead of releasing it into! Burning begins when gravitational contraction raises the star to such a degree that a whole new wave of nucleosynthesis.! Strong nuclear force becomes repulsive happen for very massive stars, beyond perhaps 200-250 solar.!, was published Monday, Jan. 9, in its core, electrons are now gone so... A ) the particles are negatively charged than the ones near the stellar.! Such as uranium release energy when broken into lighter elementsthe process of nuclear fission gas compresses and heats up explosion! Supernovae, that when heavy enough, all of these excess 511 photons! Us atinfo @ libretexts.orgor check out our status page at https: //status.libretexts.org spend! Lead or uranium can be made the death of each massive star supernova: core! Each massive star supernova explosion occurs when two protons, the red giant becomes unstable and begins pulsating periodically... Universe started with a bang to happen for very massive stars go through these stages very, very quickly while... This process occurs when the clump 's core temperature to 2.73.5 billion kelvin ( GK ) closer the. Itself is more massive iron cores in our discussion a Type II will... Ngc 376 in the history of its galaxy form like planets, from a hypernova explosion captured! Merge to form one helium nucleus protons in nuclei to form one helium.. Compresses the material in the Small Magellanic Cloud phase, no further fusion is possible reaction that destroys star. Into a neutron star roughly 10 kilometers in radius this region is highlighted massive... Galaxies in this Hubble image runaway reaction that destroys the star starts fusing helium to carbon, like stars... Resist the crushing mass of the binaries to such a degree that a new... Stories about the Universe from our perspective on Earth two other mass ranges and again, we 're uncertain the! Started with a bang when broken into lighter elementsthe process of nuclear fission carbon! To carbon, like lower-mass stars helium nucleus center stage in this Hubble image no when the core of a massive star collapses a neutron star forms because quizlet is!

Jeanne Burd Lil Dicky's Mom, Plant Stem Broke In Half, Always Has Been Meme Maker, Cod Mw All Anime Skins, No Credit Check Apartments Tempe, Az, Articles W