Interacting galaxy

Short description: Galaxies with interacting gravitational fields

NGC 3169 (left) and NGC 3166 (right) display some curious features, demonstrating that each member of the duo is close enough to feel the distorting gravitational influence of the other. Image from the Wide Field Imager on the MPG/ESO 2.2-metre telescope at the La Silla Observatory.

Interacting galaxies (colliding galaxies) are galaxies whose gravitational fields result in a disturbance of one another. An example of a minor interaction is a satellite galaxy disturbing the primary galaxy's spiral arms. An example of a major interaction is a galactic collision, which may lead to a galaxy merger.

## Contents

* 1 Satellite interaction
* 2 Galaxy collision
* 3 Gallery
* 4 Galactic cannibalism
* 5 Galaxy harassment
* 6 Notable interacting galaxies
* 7 Future collision of the Milky Way with Andromeda
* 8 See also
* 9 References
* 10 External links

## Satellite interaction

A giant galaxy interacting with its satellites is common. A satellite's gravity could attract one of the primary's spiral arms. Alternatively, the secondary satellite can dive into the primary galaxy, as in the Sagittarius Dwarf Elliptical Galaxy diving into the Milky Way. That can possibly trigger a small amount of star formation. Such orphaned clusters of stars were sometimes referred to as "blue blobs" before they were recognized as stars.[1] File:Galaxy Collision Animation- James Webb Space Telescope Science.webm

## Galaxy collision

Two galaxing merging into NGC 5256.

Colliding galaxies are common during galaxy evolution.[2] The extremely tenuous distribution of matter in galaxies means these are not collisions in the traditional sense of the word, but rather gravitational interactions.

Colliding may lead to merging if two galaxies collide and do not have enough momentum to continue traveling after the collision. As with other galaxy collisions, the merging of two galaxies may create a starburst region of new stars.[3] In that case, they fall back into each other and eventually merge into one galaxy after many passes through each other. If one of the colliding galaxies is much larger than the other, it will remain largely intact after the merger. The larger galaxy will look much the same, while the smaller galaxy will be stripped apart and become part of the larger galaxy. When galaxies pass through each other, unlike during mergers, they largely retain their material and shape after the pass.

Galactic collisions are now frequently simulated on computers, which use realistic physics principles, including the simulation of gravitational forces, gas dissipation phenomena, star formation, and feedback. Dynamical friction slows the relative motion of galaxy pairs, which may possibly merge at some point, according to the initial relative energy of the orbits. A library of simulated galaxy collisions can be found at the Paris Observatory website GALMER.[4]

## Gallery

* UGC 2369 taken by HST.[5]

* Close encounter at IRAS 06076-2139.[6]

* Interacting galaxies NGC 4302 and NGC 4298 both located 55 million light-years away.[7]

* Galaxy NGC 6052 merging into a single structure.[8]

* Galaxy pair Zw I 136.[9]

* ESO 576-69 is believed to be the nucleus of a former spiral galaxy.[10]

* The Whirlpool Galaxy with its satellite NGC 5195.

* The Mice Galaxies.

* This simulation follows the collision of two spiral galaxies that harbour giant black holes.

* NGC 3447 comprises a couple of interacting galaxies.[11]

* Barred spiral galaxy NGC 1512 in the process of a lengthy merger with dwarf elliptical galaxy NGC 1510.

* ESO 593-8 is an impressive pair of interacting galaxies with a feather-like galaxy crossing a companion galaxy.

* Antennae Galaxies NGC 4038 & NGC 4039 are a pair of interacting galaxies in the constellation Corvus.

## Galactic cannibalism

2MASX J16270254+4328340 galaxy has merged with another galaxy leaving a fine mist, made of millions of stars, spewing from it in long trails.[12]

Galactic cannibalism is a common phenomenon.[13] It refers to the process in which a large galaxy, through tidal gravitational interactions with a companion, merges with that companion. The most common result of the gravitational merger between two or more galaxies is a larger irregular galaxy, but elliptical galaxies may also result.

It has been suggested that galactic cannibalism is currently occurring between the Milky Way and the Large and Small Magellanic Clouds. Streams of gravitationally-attracted hydrogen arcing from these dwarf galaxies to the Milky Way is taken as evidence for the theory.

## Galaxy harassment

Galaxy harassment is a type of interaction between a low-luminosity galaxy and a brighter one that takes place within rich galaxy clusters, such as Virgo and Coma, where galaxies are moving at high relative speeds and suffering frequent encounters with other systems of the cluster due to the high galactic density.

According to computer simulations, the interactions convert the affected galaxy disks into disturbed barred spiral galaxies and produces starbursts followed by, if more encounters occur, loss of angular momentum and heating of their gas. The result would be the conversion of (late type) low-luminosity spiral galaxies into dwarf spheroidals and dwarf ellipticals.[14]

Evidence for the hypothesis had been claimed by studying early-type dwarf galaxies in the Virgo Cluster and finding structures, such as disks and spiral arms, which suggest they are former disc systems transformed by the above-mentioned interactions.[15] However, the existence of similar structures in isolated early-type dwarf galaxies, such as LEDA 2108986, has undermined this hypothesis[16][17]

## Notable interacting galaxies

Montage of some well known interacting galaxies Name  | Type | Distance
(million ly)  | Magnitude | Notes

|
|
|
|

Milky Way Galaxy, LMC and SMC | SBc/SB(s)m/SB(s)m pec  | 0  |  | Satellites interacting with their primary
Whirlpool Galaxy (M51)  | SAc (SB0-a)  | 37  | +8.4  | Satellite interacting with its primary
NGC 1097 | SB(s)bc (E6)  | 45  | +9.5  | Satellite interacting with its primary
Butterfly galaxies NGC 4567/8 | SA(rs)bc / SA(rs)bc | 60 | +10.9 | Early phase of interaction
NGC 2207 and IC 2163 | SAc/SAbc  | 114  | +11  | galaxies going through the first phase in galactic collision
Mice Galaxies (NGC 4676A and NGC 4676B)  | S0/SB(s)ab  | 300  | +13.5  | galaxies going through the second phase in galactic collision
Antennae Galaxies (NGC 4038/9)  | SAc/SBm  | 45  | +10.3  | galaxies going through the third phase in galactic collision
NGC 520 | S  | 100  | +11.3  | galaxies going through the third phase in galactic collision
NGC 2936 | Irr  | 352  | +12.9  | ?

## Future collision of the Milky Way with Andromeda

Main article: Astronomy:Andromeda–Milky Way collision

Astronomers have estimated the Milky Way Galaxy will collide with the Andromeda Galaxy in about 4.5 billion years. It is thought that the two spiral galaxies will eventually merge to become an elliptical galaxy[18][19] or perhaps a large disc galaxy.[20]

## See also

* NGC 7318

## References

1. ↑ "HubbleSite: News - Hubble Finds that "Blue Blobs" in Space Are Orphaned Clusters of Stars". http://hubblesite.org/news_release/news/2008-02.
2. ↑ "How the Hubble Space Telescope Changed Our View of the Cosmos". April 21, 2015. https://www.space.com/29157-hubble-space-telescope-science-legacy.html.
3. ↑ Gianopoulos, Andrea (2022-02-18). "Galaxy Collision Creates 'Space Triangle' in New Hubble Image". http://www.nasa.gov/image-feature/goddard/2022/galaxy-collision-creates-space-triangle-in-new-hubble-image.
4. ↑ "GALMER". http://galmer.obspm.fr.
5. ↑ "Galactic Creatures at Play" (in en). https://www.spacetelescope.org/images/potw1931a/.
6. ↑ "Close encounter". https://www.spacetelescope.org/images/potw1719a/.
7. ↑ "A close galactic pair". https://www.spacetelescope.org/images/heic1709a/.
8. ↑ "Two become one". http://www.spacetelescope.org/images/potw1552a/.
9. ↑ "Galactic soup". ESA/Hubble Picture of the Week. http://www.spacetelescope.org/images/potw1432a/.
10. ↑ "The messy result of a galactic collision". ESA/Hubble Picture of the Week. http://www.spacetelescope.org/images/potw1321a/.
11. ↑ "Defying cosmic convention". https://www.spacetelescope.org/images/potw1712a/.
12. ↑ "The last waltz". http://www.spacetelescope.org/images/potw1547a/.
13. ↑ "APOD: 2010 July 17 - Galaxies in the River". https://apod.nasa.gov/apod/ap100717.html.
14. ↑ "Galaxy Harassment". https://supernova.lbl.gov/~evlinder/umass/sumold/nk/harass.html.
15. ↑ Barazza, F. D.; Binggeli, B.; Jerjen, H. (2002-09-01). "More evidence for hidden spiral and bar features in bright early-type dwarf galaxies". Astronomy and Astrophysics 391 (3): 823–831. doi:10.1051/0004-6361:20020875. ISSN 0004-6361. Bibcode: 2002A&A...391..823B. https://ui.adsabs.harvard.edu/abs/2002A&A...391..823B.
16. ↑ Graham, Alister W.; Janz, Joachim; Penny, Samantha J.; Chilingarian, Igor V.; Ciambur, Bogdan C.; Forbes, Duncan A.; Davies, Roger L. (2017-05-01). "Implications for the Origin of Early-type Dwarf Galaxies: A Detailed Look at the Isolated Rotating Early-type Dwarf Galaxy LEDA 2108986 (CG 611), Ramifications for the Fundamental Plane's {S}_{K}^{2} Kinematic Scaling, and the Spin-Ellipticity Diagram". The Astrophysical Journal 840 (2): 68. doi:10.3847/1538-4357/aa6e56. ISSN 0004-637X. Bibcode: 2017ApJ...840...68G.
17. ↑ Janz, Joachim; Penny, Samantha J.; Graham, Alister W.; Forbes, Duncan A.; Davies, Roger L. (2017-07-01). "Implications for the origin of early-type dwarf galaxies - the discovery of rotation in isolated, low-mass early-type galaxies". Monthly Notices of the Royal Astronomical Society 468 (3): 2850–2864. doi:10.1093/mnras/stx634. ISSN 0035-8711. Bibcode: 2017MNRAS.468.2850J. https://ui.adsabs.harvard.edu/abs/2017MNRAS.468.2850J.
18. ↑ whose gravitational interactions will fling various celestial bodies outward, evicting them from the resulting elliptical galaxy.Hazel Muir (2007-05-14). "Galactic merger to 'evict' Sun and Earth". New Scientist. https://www.newscientist.com/article/dn11852-galactic-merger-to-evict-sun-and-earth.html#.VDVdDvl_uVB.
19. ↑ Astronomy, June 2008, page 28, by Abraham Loeb and T.J.Cox
20. ↑ Junko Ueda (2014). "Cold molecular gas in merger remnants. I. Formation of molecular gas disks". The Astrophysical Journal Supplement Series 214 (1): 1. doi:10.1088/0067-0049/214/1/1. Bibcode: 2014ApJS..214....1U.

## External links

* Galaxy Collisions
* Galactic cannibalism
* Galactic Collision Simulation
* GALMER: Galaxy Merger Simulations

* v
* t
* e

Galaxies

Morphology|

* Disc
* Lenticular
* barred
* unbarred
* Spiral
* anemic
* barred
* flocculent
* grand design
* intermediate
* Magellanic
* unbarred
* Dwarf galaxy
* elliptical
* irregular
* spheroidal
* spiral
* Elliptical galaxy
* cD
* Irregular
* barred
* Peculiar
* Ring
* Polar

Structure|

* Active galactic nucleus
* Bar
* Bulge
* Dark matter halo
* Disc
* Disc galaxy
* Halo
* corona
* Galactic center
* Galactic plane
* Galactic ridge
* Interstellar medium
* Protogalaxy
* Spiral arm
* Supermassive black hole

Active nuclei|

* Blazar
* LINER
* Markarian
* Quasar
* Radio
* X-shaped
* Relativistic jet
* Seyfert

Energetic galaxies|

* Lyman-alpha emitter
* Luminous infrared
* Starburst
* blue compact dwarf
* pea
* faint blue
* Hot dust-obscured

Low activity|

* Low surface brightness
* Ultra diffuse
* Dark galaxy

Interaction|

* Field
* Galactic tide
* Cloud
* Groups and clusters
* group
* cluster
* Brightest cluster galaxy
* fossile group
* Interacting
* merger
* Jellyfish
* Satellite
* Stellar stream
* Superclusters
* Walls
* Voids and supervoids
* void galaxy

Lists|

* Galaxies
* Galaxies named after people
* Largest
* Nearest
* Polar-ring
* Ring
* Spiral
* Groups and clusters
* Large quasar groups
* Quasars

* Superclusters
* Voids

See also|

* Extragalactic astronomy
* Galactic astronomy
* Galactic coordinate system
* Galactic empire
* Galactic habitable zone
* Galactic magnetic fields
* Galactic orientation
* Galactic quadrant
* Galaxy color–magnitude diagram
* Galaxy formation and evolution
* Galaxy rotation curve
* Illustris project
* Intergalactic dust
* Intergalactic stars
* Intergalactic travel
* Population III stars

* Book
* Category
* Portal

0.00

(0 votes)

Original source: https://en.wikipedia.org/wiki/Interacting galaxy. Read more

|

Retrieved from "https://handwiki.org/wiki/index.php?title=Astronomy:Interacting_galaxy&oldid=375643"
*[v]: View this template
*[t]: Discuss this template
*[e]: Edit this template