:Antennae Galaxies

{{Short description|Interacting galaxies in the constellation Corvus}}

{{Infobox Galaxy

| name = Antennae Galaxies

| image = Antennae Galaxies reloaded.jpg

|caption = Hubble Space Telescope image of NGC 4038 (top) and NGC 4039 (bottom)

| constellation name = Corvus{{cite book

| editor=R. W. Sinnott

| title= The Complete New General Catalogue and Index Catalogue of Nebulae and Star Clusters by J. L. E. Dreyer

| date=1988

| publisher=Sky Publishing Corporation and Cambridge University Press

| isbn=978-0-933346-51-2}}

| epoch = J2000

| type = SB(s)m pec / SA(s)m pec{{cite web

| title=NASA/IPAC Extragalactic Database

| work=Results for NGC 4038 / 4039

| url=http://nedwww.ipac.caltech.edu/

| access-date=2006-12-07 }}

| ra = {{RA|12|01|53.0}} / {{RA|12|01|53.6}}

| dec = {{DEC|-18|52|10}} / {{DEC|-18|53|11}}

| dist_ly = 45 Mly / 65 Mly

| z = 1642 ± 12 / 1641 ± 9 km/s

| appmag_v = 11.2 / 11.1

| size_v = 5.2{{prime}} × 3.1{{prime}} / 3.1{{prime}} × 1.6{{prime}}

| size = {{convert|500,000|ly|kpc|abbr=on}}{{cite web|author=Astronomy Picture of the Day Archive|url=https://apod.nasa.gov/apod/ap170428.html|date=28 April 2017|title=Exploring the Antennae|access-date=2018-05-01}}{{efn|The quoted size is based on an assumed distance around 60 million ly although a more recent study gives a less remote distance of 45 million ly, giving consequently smaller values for the size.}}

| notes = Interacting galaxies

| names = Ringtail Galaxy, NGC 4038 / 4039,
PGC 37967 / 37969, Arp 244, Caldwell 60/61, UGCA 264/265

}}

The Antennae Galaxies (also known as NGC 4038/NGC 4039 or Caldwell 60/Caldwell 61) are a pair of interacting galaxies in the constellation Corvus. They are currently going through a starburst phase, in which the collision of clouds of gas and dust, with entangled magnetic fields, causes rapid star formation. They were discovered by William Herschel in 1785.{{cite web

| title=Corvus

| work=Universe Today

| url=http://www.universetoday.com/guide-to-space/constellations/corvus/

| access-date=2006-12-07 }}

General information

File:Antennae Galaxies composite of ALMA and Hubble observations.jpg showing the clouds of dense cold gas from which new stars form (red, pink and yellow)]]

File:NGC4038 Large 01.jpg

The Antennae Galaxies are undergoing a galactic collision. These interacting galaxies are located 0.25° north of 31 Crateris and 3.25° southwest of Gamma Corvi.{{cite book |title=The Caldwell Objects |first=Stephen James |last=O'Meara |publisher=Cambridge University Press |year=2002 |pages=240–43 |isbn=978-0-521-82796-6 | url=https://books.google.com/books?id=3Hg6YHgx9nAC&pg=PA242}} A 2008 study found that they are less remote from the Milky Way than previously thought—at 45 million light-years instead of 65 million light-years.{{cite web

| title= The Antennae Galaxies Found To Be Closer To Us

| work=Space Daily

| date=2008-05-12

| url=http://www.spacedaily.com/reports/The_Antennae_Galaxies_Found_To_Be_Closer_To_Us_999.html

| access-date=2008-06-30}}

Located in the NGC 4038 group with five other galaxies, these two galaxies are known as the Antennae Galaxies because the two long tails of stars, gas and dust ejected from the galaxies as a result of the collision resemble an insect's antennae.

The nuclei of the two galaxies are joining to become one giant galaxy. Most galaxies probably undergo at least one significant collision in their lifetimes. This is likely the future of our Milky Way when it collides with the Andromeda Galaxy. This collision and merger sequence (the Toomre sequence) for galaxy evolution was developed in part by successfully modeling the Antennae Galaxies' "antennae" in particular.

The Antennae galaxies also contain a relatively young collection of massive globular clusters that were possibly formed as a result of the collision between the two galaxies.{{Cite journal|title=van den Bergh, How Did Globular Clusters Form?|journal=The Astrophysical Journal|volume=559|issue=2|pages=L113–L114|doi=10.1086/323754|arxiv=astro-ph/0108298|year=2001|last1=Van Den Bergh|first1=Sidney|bibcode=2001ApJ...559L.113V|s2cid=44060272}} The young age of these clusters is in contrast to the average age of most known globular clusters (which are around 12 billion years old), with the formation of the globulars likely originating from shockwaves, generated by the collision of the galaxies, compressing large, massive molecular clouds. The densest regions of the collapsing and compressing clouds are believed to be the birthplace of the clusters.

NGC 4038 has a lot of Cepheid Variables, around 53 of them. {{Cite simbad|title=NGC 4038|access-date=10 December 2024}}

Supernovae

Four supernovae have been observed in NGC 4038.

SN 1974E (type unknown, mag. 14){{cite web | website=Transient Name Server | title=SN 1974E | url=https://www.wis-tns.org/object/1974E |publisher = IAU | access-date=17 August 2024}} was discovered by Miklós Lovas on 21 March 1974.
SN 2004gt (type Ic, mag. 14.9){{cite web | website=Transient Name Server | title=SN 2004gt | url=https://www.wis-tns.org/object/2004gt | publisher = IAU | access-date=17 August 2024}} was discovered by Berto Monard on 12 December 2004.{{cite journal | bibcode=2004IAUC.8454....1M | title=Supernovae 2004gt, 2004gu, 2004gv | last1=Monard | first1=L. A. G. | last2=Quimby | first2=R. | last3=Gerardy| first3=C.| last4=Hoeflich| first4=P. | last5=Wheeler | first5=J. C. | last6=Chen | first6=Y. -T.| last7=Smith | first7=H. J. | last8=Bauer | first8=A. | journal=International Astronomical Union Circular | date=2004 | issue=8454 | page=1}}
SN 2007sr (type Ia, mag. 12.9) was discovered by the Catalina Sky Survey on 18 December 2007.{{cite web | website=Transient Name Server | title=SN 2007sr | url=https://www.wis-tns.org/object/2007sr |publisher = IAU | access-date=17 August 2024}}{{cite journal | bibcode=2007CBET.1172....1D | title=Supernova 2007sr in NGC 4038 | last1=Drake | first1=A. J. | last2=Djorgovski | first2=S. G. | last3=Williams | first3=R. | last4=Mahabal | first4=A. | last5=Graham | first5=M. J. | last6=Christensen | first6=E. | last7=Beshore | first7=E. C.| last8=Larson | first8=S. M. | journal=Central Bureau Electronic Telegrams | date=2007 | volume=1172 | page=1}}
SN 2013dk (type Ic, mag. 15.8){{cite web | website=Transient Name Server | title=SN 2013dk | url=https://www.wis-tns.org/object/2013dk |publisher = IAU | access-date=17 August 2024}} was discovered by the CHASE Project (CHilean Automatic Supernovas sEarch) on 22 June 2013.{{cite journal | bibcode = 2013CBET.3565....1C| title = Supernova 2013dk in NGC 4038 = PSN J12015272-1852183| last1 = Carrasco| first1 = F.| last2 = Hamuy| first2 = M.| last3 = Antezana| first3 = R.| last4 = Gonzalez| first4 = L.| last5 = Cartier| first5 = R.| last6 = Forster| first6 = F.| last7 = Silva| first7 = S.| last8 = Ramirez| first8 = R.| last9 = Pignata| first9 = G.| last10 = Apostolovski| first10 = Y.| last11 = Paillas| first11 = E.| last12 = Varela| first12 = S.| last13 = Aros| first13 = F.| last14 = Conuel| first14 = B.| last15 = Folatelli| first15 = G.| last16 = Reichart| first16 = D. E.| last17 = Haislip| first17 = J. B.| last18 = Moore| first18 = J. P.| last19 = Lacluyze| first19 = A. P.| last20 = Vinko| first20 = J.| last21 = Marion| first21 = G. H.| last22 = Silverman| first22 = J. M.| last23 = Wheeler| first23 = J. C.| last24 = Szalai| first24 = T.| last25 = Quimby| first25 = R.| journal = Central Bureau Electronic Telegrams| date = 2013| volume = 3565| page = 1}}

One supernova has been found in NGC 4039.

SN 1921A (type unknown, mag. 16){{cite web | website=Transient Name Server | title=SN 1921A | url=https://www.wis-tns.org/object/1921A |publisher = IAU | access-date=17 August 2024}} {{Cite simbad|title=SN 1921A|access-date=10 December 2024}} was discovered by Edwin Hubble and John Charles Duncan in March 1921.

Timeline

About 1.2 billion years ago, the Antennae were two separate galaxies.{{cite journal

| author=J. E. Barnes | author2=L. Hernquist

| title=Dynamics of interacting galaxies

| journal=Annual Review of Astronomy and Astrophysics

| date=1992

| volume=30

| issue=1

| pages=705–742

| bibcode=1992ARA&A..30..705B | doi=10.1146/annurev.aa.30.090192.003421

}} NGC 4038 was a barred spiral galaxy and NGC 4039 was a spiral galaxy. 900 million years ago, the Antennae began to approach one another, looking similar to NGC 2207 and IC 2163. 600 million years ago, the Antennae passed through each other, looking like the Mice Galaxies. 300 million years ago, the Antennae's stars began to be released from both galaxies. Today the two streamers of ejected stars extend far beyond the original galaxies, resulting in the antennae shape.{{cite web|url=https://nasa.gov/feature/goddard/caldwell-60-61|title=Caldwell 60/61|last=Henderson|first=Edward|date=2019-12-18|work=NASA|access-date=9 November 2021}}

Within 400 million years, the Antennae's nuclei will collide and become a single core with stars, gas, and dust around it.{{cite web|url=https://gizmodo.com/antennae-galaxies-are-slowly-colliding-in-beautiful-cha-5605407|title=Antennae Galaxies are slowly colliding in beautiful chaos of black holes|last=Wilkins|first=Alasdair|date=2010-08-05|work=Gizmodo|access-date=9 November 2021}} Observations and simulations of colliding galaxies (e.g., by Alar Toomre) suggest that the Antennae Galaxies will eventually form an elliptical galaxy.{{page number needed|date=October 2020}}

X-ray source

Areas containing large amounts of neon (Ne), magnesium (Mg), and silicon (Si) were found when the Chandra X-ray Observatory analyzed the Antennae Galaxies. Heavy elements such as these are necessary in order for planets that may contain life (as we know it) to form. The clouds imaged contain 16 times as much magnesium and 24 times as much silicon as the Sun.

References

Notes

External links

Astronomy Picture of the Day: [http://antwrp.gsfc.nasa.gov/apod/ap971022.html The Antennae Galaxies (10/22/1997)]
Astronomy Picture of the Day: [http://apod.nasa.gov/apod/ap100507.html The Antennae (05/07/2010)]
Astronomy Picture of the Day: [http://apod.nasa.gov/apod/ap110429.html The Antennae (04/29/2011)]
Astronomy Picture of the Day: [http://apod.nasa.gov/apod/ap150212.html The Antennae (02/12/2015)]
[https://www.theregister.co.uk/2005/03/30/colliding_galaxies/ The Register: Galactic prang fingered in star formation mystery]
[http://www.spacetelescope.org/news/html/heic0615.html ESA/Hubble News Release]
[http://www.spacetelescope.org/images/archive/freesearch/antennae+galaxies/viewall/1 ESA/Hubble images of Antennae Galaxies]
[http://www.cita.utoronto.ca/~dubinski/antennae/antennae.html Animations of galactic collision producing antennae structures]
{{WikiSky|1=NGC 4038}}
[http://www.constellation-guide.com/antennae-galaxies/ Antennae Galaxies at Constellation Guide]