NGC 4889

Coma B
Observation data Epoch J2000.0

The NGC 4889 galaxy
Credit: Sloan Digital Sky Survey, Spitzer Space Telescope
Constellation	Coma Berenices
Right ascension	13^h 00^m 08.1^s^[1]
Declination	+27° 58′ 37″^[1]
Apparent dimension (V)	2.9' × 1.9'^[1]
Apparent magnitude (V)	12.9^[1]
Characteristics
Type	cD; E4; Dd^[1]
Astrometry
Heliocentric radial velocity	6495^[1] ± 13^[1] km/s
Redshift	0.021665^[1]
Galactocentric velocity	6509^[1] ± 13^[1] km/s
Distance	308 ± 3^[2] Mly (94.43 ± 0.92 Mpc)^[1]^[2]
Other designations
Coma B, NGC 4884, UGC 8110, MCG 5-31-77, PGC 44715, ZWG 160.241, DRCG 27-148,^[3] Caldwell 35
Database references
SIMBAD	data
See also: Galaxy, List of galaxies

NGC 4889 (also known as Caldwell 35, Coma B) is a class-4 supergiant elliptical galaxy.^[4] It was discovered in 1785 by the British astronomer Frederick William Herschel I, who catalogued it as a bright, nebulous patch. The brightest galaxy within the northern Coma Cluster, it is located at a distance of 94 million parsecs (308 million light years) from Earth. Unlike a flattened, disc-shaped spiral galaxy like the Milky Way, NGC 4889 has no visible dust lanes or spiral arms and has a smooth, featureless, egg-shaped profile that diminishes in luminosity with distance from the center. At the core of the galaxy is a supermassive black hole that heats the intracluster medium through the action of friction from infalling gases and dust. The X-ray emission from the galaxy extends out to several million light years of the cluster.

As with other similar elliptical galaxies, only a fraction of the mass of NGC 4889 is in the form of stars. They have a flattened, unequal distribution that bulges within its edge. Between the stars is a dense interstellar medium full of heavy elements emitted by evolved stars. The diffuse stellar halo extends out to one million light years in diameter. Orbiting the galaxy is a very large population of globular clusters. NGC 4889 is also a strong source of soft X-ray, ultraviolet, and radio frequency radiation.

As the largest and the most massive galaxy easily visible to Earth, NGC 4889 has played an important role in both amateur and professional astronomy, and has become a prototype in studying the dynamical evolution of other supergiant elliptical galaxies in the more distant universe.

Observation

Wide-field image of the Coma Cluster. NGC 4889 is the bright galaxy to the left. The galaxy at the right is NGC 4874, while the star above it is HD 112887 which is a foreground star and is completely unrelated to the cluster.

NGC 4889 was not included by the astronomer Charles Messier in his famous Messier catalogue despite being an intrinsically bright object quite close to some Messier objects. The first known observation of NGC 4889 was that of Frederick William Herschel I, assisted by his sister, Caroline Lucretia Herschel, in 1785, who included it in the Catalogue of Nebulae and Clusters of Stars published a year later. In 1864, Herschel's son, John Frederick William Herschel, published the General Catalogue of Nebulae and Clusters of Stars. He included the objects catalogued by his father, including the one later to be called NGC 4889, plus others he found that were somehow missed by his father.

In 1888 the astronomer John Louis Emil Dreyer published the New General Catalogue of Nebulae and Clusters of Stars (NGC), with a total of 7,840 objects, but he erroneously duplicated the galaxy in two designations, NGC 4884 and NGC 4889. Within the following century, several projects aimed to revise the NGC catalogue were conducted, such as The NGC/IC Project, Revised New General Catalogue of Nebulae and Clusters of Stars, and the NGC 2000.0 projects, discovered the duplication. It was then decided that the object to be called by its latter designation, NGC 4889, which is in use today.

In December 1995, Patrick Caldwell Moore compiled the Caldwell catalogue, a list of 109 persistent, bright objects that were somehow missed by Messier in his catalogue. The list also includes NGC 4889, which is given the designation Caldwell 35.

Properties

The location of NGC 4889 (circled) in Coma Berenices

NGC 4889 is located along the high declination region of Coma Berenices, south of the constellation Canes Venatici. It can be traced by following the line from Beta Comae Berenices to Gamma Comae Berenices. With an apparent magnitude of 11.4, it can be seen by telescopes with 12 inch aperture, but its visibility is greatly affected by light pollution due to glare of the light from Beta Comae Berenices. However, under very dark, moonless skies, it can be seen by small telescopes as a faint smudge, but larger telescopes are needed in order to see the galaxy's halo.

In the updated Hubble sequence galaxy morphological classification scheme by the French astronomer Gérard de Vaucouleurs in 1959, NGC 4889 is classified as an E4 type galaxy, which means it has a flat distribution of stars within its width. It is also classified as a cD galaxy, a giant type of D galaxy, a classification devised by the American astronomer William Wilson Morgan in 1958 for galaxies with an elliptical-shaped nucleus surrounded by an immense, diffuse, dustless, extended halo.

NGC 4889 is far enough that its distance can be measured using redshift. With the redshift of 0.0266 as derived from the Sloan Digital Sky Survey, and the Hubble constant as determined in 2013 by the ESA COBRAS/SAMBA/Planck Surveyor translates its distance of 94 Mpc (308 million light years) from Earth.

NGC 4889 is probably the largest and the most massive galaxy out to the radius of 100 Mpc (326 million light years) of the Milky Way. The galaxy has an effective radius which extends at 2.9 arcminutes of the sky, translating it to the diameter of 239,000 light years, about the size of the Andromeda Galaxy. In addition it has an immense diffuse light halo extending to 17.8 arcminutes, roughly half the angular diameter of the Sun, translating to 1.3 million light years in diameter.

As for its large size, NGC 4889 may also be extremely massive. If we took Milky Way as the standard of mass, it may be close to 8 trillion solar masses. However, as NGC 4889 is a spheroid, and not a flat spiral, it has a three-dimensional profile, so it may be as high as 15 trillion solar masses. However, as for elliptical galaxies, only a small fraction of the mass of NGC 4889 is in the form of stars that radiate energy. Assuming a mass to light ratio of 6.5 as with other elliptical galaxies, NGC 4889 may be a thousand times more massive than the Milky Way.

Components

Elliptical galaxy NGC 4889 in front of hundreds of background galaxies.^[5]

On December 5, 2011, astronomers measured the velocity dispersion of the central regions of two massive galaxies, NGC 4889, and the other being NGC 3842 in the Leo Cluster. According to the data of the study, they found out the central black hole of NGC 4889 is 5,200 times more massive than the central black hole of the Milky Way, or equivalent to 2.1×10¹⁰ (21 billion) solar masses (best fit of data; possible range is from 6 billion to 37 billion solar masses).^[6] This makes it one of the most massive black holes on record. The diameter of the black hole's immense event horizon is about 20 to 124 billion kilometers, 2 to 12 times the diameter of Pluto's orbit. The ionized medium detected around the black hole suggests that NGC 4889 may have been a quasar in the past. It is quiescent, presumably because it has already absorbed all readily available matter.^[7]

Giant elliptical galaxies like NGC 4889 are believed to be the result of multiple mergers of smaller galaxies. There is now little dust remaining to form the diffuse nebulae where new stars are created, so the stellar population is dominated by old, population II stars that contain relatively low abundances of elements other than hydrogen and helium. The egg-like shape of this galaxy is maintained by random orbital motions of its member stars, in contrast to the more orderly rotational motions found in a spiral galaxy such as the Milky Way.

The space between the stars in the galaxy is filled with a diffuse interstellar medium of gas, which has been filled by the elements ejected from stars as they passed beyond the end of their main sequence lifetime. Carbon and nitrogen are being continuously supplied by intermediate mass stars as they pass through the asymptotic giant branch. The heavier elements from oxygen to iron are primarily produced by supernova explosions within the galaxy. The interstellar medium is continuously heated by the emission of in-falling gases towards its central SMBH.

Environment

The Coma Cluster taken using data from the Sloan Digital Sky Survey and the Spitzer Space Telescope. NGC 4889 is at the center.

NGC 4889 lies at the center of the component A of the Coma Cluster, a giant cluster of 20,000 galaxies which it shares with NGC 4874, although NGC 4889 is sometimes referred as the cluster center, and it has been called by its other designation A1656-BCG. The total mass of the cluster is estimated to be on the order of 4×10¹⁵ M_☉.

The Coma Cluster is located at exactly the center of the Coma Supercluster, which is one of the nearest superclusters to the Laniakea Supercluster. The Coma Supercluster itself is within the CfA Homunculus, the center of the CfA2 Great Wall, the nearest galaxy filament to Earth and one of the largest structures in the known universe.

Notes

1 2 3 4 5 6 7 8 9 10 11 "NASA/IPAC Extragalactic Database". Results for NGC 4889. Retrieved 2015-01-04.
1 2 "Distance Results for NGC 4889". NASA/IPAC Extragalactic Database. Retrieved 2015-01-04.
↑ "Revised NGC Data for NGC 4889". spider.seds.org. Retrieved 2015-10-13.
↑ Jacobsen, Den (2006). "Abell 1656, NGC 4889, NGC 4874". astrophoto.net. Retrieved 2008-08-09.
↑ "The sleeping giant". Retrieved 16 February 2016.
↑ McConnell, Nicholas J. (2011-12-08). "Two ten-billion-solar-mass black holes at the centres of giant elliptical galaxies". Nature. Archived from the original (PDF) on 2011-12-06. Retrieved 2011-12-06.
↑ "Astronomers find supermassive black hole in giant galaxy 300 million light years away | Fox News". Fox News. 2016-02-18. Retrieved 2016-02-20.

References

Pasachoff, Jay M. (2000). "Atlas of the Sky". Stars and Planets. New York, NY: Peterson Field Guides. ISBN 0-395-93432-X.
Eicher, David J. (1988). The Universe from Your Backyard: A Guide to Deep-Sky Objects from Astronomy Magazine. AstroMedia (Kalmbach Publishing Company). ISBN 0-521-36299-7.

External links

Wikimedia Commons has media related to Special:Search/NGC_4889.

NGC 4889 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images
The Scale of the Universe (Astronomy Picture of the Day 2012 March 12)

New General Catalogue 4500 to 4999

NGC 4500 NGC 4501 NGC 4502 NGC 4503 NGC 4504 NGC 4505 NGC 4506 NGC 4507 NGC 4508 NGC 4509 NGC 4510 NGC 4511 NGC 4512 NGC 4513 NGC 4514 NGC 4515 NGC 4516 NGC 4517 NGC 4518 NGC 4519 NGC 4520 NGC 4521 NGC 4522 NGC 4523 NGC 4524 NGC 4525 NGC 4526 NGC 4527 NGC 4528 NGC 4529 NGC 4530 NGC 4531 NGC 4532 NGC 4533 NGC 4534 NGC 4535 NGC 4536 NGC 4537 NGC 4538 NGC 4539 NGC 4540 NGC 4541 NGC 4542 NGC 4543 NGC 4544 NGC 4545 NGC 4546 NGC 4547 NGC 4548 NGC 4549 NGC 4550 NGC 4551 NGC 4552 NGC 4553 NGC 4554 NGC 4555 NGC 4556 NGC 4557 NGC 4558 NGC 4559 NGC 4560 NGC 4561 NGC 4562 NGC 4563 NGC 4564 NGC 4565 NGC 4566 NGC 4567 NGC 4568 NGC 4569 NGC 4570 NGC 4571 NGC 4572 NGC 4573 NGC 4574 NGC 4575 NGC 4576 NGC 4577 NGC 4578 NGC 4579 NGC 4580 NGC 4581 NGC 4582 NGC 4583 NGC 4584 NGC 4585 NGC 4586 NGC 4587 NGC 4588 NGC 4589 NGC 4590 NGC 4591 NGC 4592 NGC 4593 NGC 4594 NGC 4595 NGC 4596 NGC 4597 NGC 4598 NGC 4599 NGC 4600 NGC 4601 NGC 4602 NGC 4603 NGC 4604 NGC 4605 NGC 4606 NGC 4607 NGC 4608 NGC 4609 NGC 4610 NGC 4611 NGC 4612 NGC 4613 NGC 4614 NGC 4615 NGC 4616 NGC 4617 NGC 4618 NGC 4619 NGC 4620 NGC 4621 NGC 4622 NGC 4623 NGC 4624 NGC 4625 NGC 4626 NGC 4627 NGC 4628 NGC 4629 NGC 4630 NGC 4631 NGC 4632 NGC 4633 NGC 4634 NGC 4635 NGC 4636 NGC 4637 NGC 4638 NGC 4639 NGC 4640 NGC 4641 NGC 4642 NGC 4643 NGC 4644 NGC 4645 NGC 4646 NGC 4647 NGC 4648 NGC 4649 NGC 4650 NGC 4651 NGC 4652 NGC 4653 NGC 4654 NGC 4655 NGC 4656 NGC 4657 NGC 4658 NGC 4659 NGC 4660 NGC 4661 NGC 4662 NGC 4663 NGC 4664 NGC 4665 NGC 4666 NGC 4667 NGC 4668 NGC 4669 NGC 4670 NGC 4671 NGC 4672 NGC 4673 NGC 4674 NGC 4675 NGC 4676 NGC 4677 NGC 4678 NGC 4679 NGC 4680 NGC 4681 NGC 4682 NGC 4683 NGC 4684 NGC 4685 NGC 4686 NGC 4687 NGC 4688 NGC 4689 NGC 4690 NGC 4691 NGC 4692 NGC 4693 NGC 4694 NGC 4695 NGC 4696 NGC 4697 NGC 4698 NGC 4699 NGC 4700 NGC 4701 NGC 4702 NGC 4703 NGC 4704 NGC 4705 NGC 4706 NGC 4707 NGC 4708 NGC 4709 NGC 4710 NGC 4711 NGC 4712 NGC 4713 NGC 4714 NGC 4715 NGC 4716 NGC 4717 NGC 4718 NGC 4719 NGC 4720 NGC 4721 NGC 4722 NGC 4723 NGC 4724 NGC 4725 NGC 4726 NGC 4727 NGC 4728 NGC 4729 NGC 4730 NGC 4731 NGC 4732 NGC 4733 NGC 4734 NGC 4735 NGC 4736 NGC 4737 NGC 4738 NGC 4739 NGC 4740 NGC 4741 NGC 4742 NGC 4743 NGC 4744 NGC 4745 NGC 4746 NGC 4747 NGC 4748 NGC 4749 NGC 4750 NGC 4751 NGC 4752 NGC 4753 NGC 4754 NGC 4755 NGC 4756 NGC 4757 NGC 4758 NGC 4759 NGC 4760 NGC 4761 NGC 4762 NGC 4763 NGC 4764 NGC 4765 NGC 4766 NGC 4767 NGC 4768 NGC 4769 NGC 4770 NGC 4771 NGC 4772 NGC 4773 NGC 4774 NGC 4775 NGC 4776 NGC 4777 NGC 4778 NGC 4779 NGC 4780 NGC 4781 NGC 4782 NGC 4783 NGC 4784 NGC 4785 NGC 4786 NGC 4787 NGC 4788 NGC 4789 NGC 4790 NGC 4791 NGC 4792 NGC 4793 NGC 4794 NGC 4795 NGC 4796 NGC 4797 NGC 4798 NGC 4799 NGC 4800 NGC 4801 NGC 4802 NGC 4803 NGC 4804 NGC 4805 NGC 4806 NGC 4807 NGC 4808 NGC 4809 NGC 4810 NGC 4811 NGC 4812 NGC 4813 NGC 4814 NGC 4815 NGC 4816 NGC 4817 NGC 4818 NGC 4819 NGC 4820 NGC 4821 NGC 4822 NGC 4823 NGC 4824 NGC 4825 NGC 4826 NGC 4827 NGC 4828 NGC 4829 NGC 4830 NGC 4831 NGC 4832 NGC 4833 NGC 4834 NGC 4835 NGC 4836 NGC 4837 NGC 4838 NGC 4839 NGC 4840 NGC 4841 NGC 4842 NGC 4843 NGC 4844 NGC 4845 NGC 4846 NGC 4847 NGC 4848 NGC 4849 NGC 4850 NGC 4851 NGC 4852 NGC 4853 NGC 4854 NGC 4855 NGC 4856 NGC 4857 NGC 4858 NGC 4859 NGC 4860 NGC 4861 NGC 4862 NGC 4863 NGC 4864 NGC 4865 NGC 4866 NGC 4867 NGC 4868 NGC 4869 NGC 4870 NGC 4871 NGC 4872 NGC 4873 NGC 4874 NGC 4875 NGC 4876 NGC 4877 NGC 4878 NGC 4879 NGC 4880 NGC 4881 NGC 4882 NGC 4883 NGC 4884 NGC 4885 NGC 4886 NGC 4887 NGC 4888 NGC 4889 NGC 4890 NGC 4891 NGC 4892 NGC 4893 NGC 4894 NGC 4895 NGC 4896 NGC 4897 NGC 4898 NGC 4899 NGC 4900 NGC 4901 NGC 4902 NGC 4903 NGC 4904 NGC 4905 NGC 4906 NGC 4907 NGC 4908 NGC 4909 NGC 4910 NGC 4911 NGC 4912 NGC 4913 NGC 4914 NGC 4915 NGC 4916 NGC 4917 NGC 4918 NGC 4919 NGC 4920 NGC 4921 NGC 4922 NGC 4923 NGC 4924 NGC 4925 NGC 4926 NGC 4927 NGC 4928 NGC 4929 NGC 4930 NGC 4931 NGC 4932 NGC 4933 NGC 4934 NGC 4935 NGC 4936 NGC 4937 NGC 4938 NGC 4939 NGC 4940 NGC 4941 NGC 4942 NGC 4943 NGC 4944 NGC 4945 NGC 4946 NGC 4947 NGC 4948 NGC 4949 NGC 4950 NGC 4951 NGC 4952 NGC 4953 NGC 4954 NGC 4955 NGC 4956 NGC 4957 NGC 4958 NGC 4959 NGC 4960 NGC 4961 NGC 4962 NGC 4963 NGC 4964 NGC 4965 NGC 4966 NGC 4967 NGC 4968 NGC 4969 NGC 4970 NGC 4971 NGC 4972 NGC 4973 NGC 4974 NGC 4975 NGC 4976 NGC 4977 NGC 4978 NGC 4979 NGC 4980 NGC 4981 NGC 4982 NGC 4983 NGC 4984 NGC 4985 NGC 4986 NGC 4987 NGC 4988 NGC 4989 NGC 4990 NGC 4991 NGC 4992 NGC 4993 NGC 4994 NGC 4995 NGC 4996 NGC 4997 NGC 4998 NGC 4999

Astronomical catalog List of NGC objects

Caldwell catalogue

List	C1 C2 C3 C4 C5 C6 C7 C8 C9 C10 C11 C12 C13 C14 C15 C16 C17 C18 C19 C20 C21 C22 C23 C24 C25 C26 C27 C28 C29 C30 C31 C32 C33 C34 C35 C36 C37 C38 C39 C40 C41 C42 C43 C44 C45 C46 C47 C48 C49 C50 C51 C52 C53 C54 C55 C56 C57 C58 C59 C60 C61 C62 C63 C64 C65 C66 C67 C68 C69 C70 C71 C72 C73 C74 C75 C76 C77 C78 C79 C80 C81 C82 C83 C84 C85 C86 C87 C88 C89 C90 C91 C92 C93 C94 C95 C96 C97 C98 C99 C100 C101 C102 C103 C104 C105 C106 C107 C108 C109

See also	Messier Catalogue Catalogue of Nebulae and Clusters of Stars New General Catalogue Index Catalogue Revised New General Catalogue Herschel 400 Catalogue

Book:Caldwell catalogue Category:Caldwell objects Portal:Astronomy Commons:Caldwell objects

This article is issued from Wikipedia - version of the 6/28/2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.