View source for NGC 4138

{{short description|Lenticular galaxy in the constellation Canes Venatici}}
{{Infobox galaxy
 | name               = NGC 4138
 | image              = File:NGC 4138 547nm.jpg
 | caption            = Image of NGC 4138 taken by the [[Hubble Space Telescope]] in green light (547 nm).
 | epoch              = [[J2000]]
 | pronounce          = 
 | constellation name = [[Canes Venatici]]
 | ra                 = {{RA|12|09|29.788}}<ref name="ApJ131_1163"/>
 | dec                = {{DEC|+43|41|07.14}}<ref name="ApJ131_1163"/>
 | z                  = 0.002962<ref name=Jore1996/>
 | h_radial_v         = 872<ref name=aj146_86/>
 | gal_v              = 
 | dist_pc            = 
 | dist_ly            = {{Convert|16.0|Mpc|Mly|abbr=on|lk=on|order=flip}}<ref name=aj146_86/>
 | group_cluster      = 
 | type               = SA0<sup>+</sup>(r)<ref name=vaucoulerus1991/>
 | mass               = <!-- In solar masses --> 
 | mass_light_ratio   = <!-- In solar units  -->
 | size               = <!-- In light years  -->
 | stars              = 
 | appmag_v           = 11.32<ref name=GAXEL/>
 | appmag_b           = 12.16<ref name=GAXEL/>
 | absmag_v           = 
 | size_v             = {{nowrap|2.087′ × 1.252′}}<ref name="ApJ131_1163"/>
 | notes              = 
 | names              = [[2MASX]] J12092978+4341071, [[Lyon-Meudon Extragalactic Database|LEDA]] 38643, [[Uppsala General Catalogue|UGC]] 7139, [[UZC]] J120929.9+434107, [[Fritz Zwicky#Catalog of Galaxies and Clusters|Z]] 215-37.<ref name=SIMBAD/>
 | references         = 
}}
'''NGC 4138'''  is the ''[[New General Catalogue]]'' identifier for a [[lenticular galaxy]] in the northern [[constellation]] of [[Canes Venatici]]. Located around 52 million [[light year]]s from Earth,<ref name=aj146_86/> it spans some 2.1&nbsp;×&nbsp;1.3<ref name="ApJ131_1163"/>&nbsp;[[arc minute]]s and has an [[apparent visual magnitude]] of 11.3.<ref name=GAXEL/> The [[Galaxy morphological classification|morphological classification]] of NGC 4138 is SA0<sup>+</sup>(r), indicating it lacks a [[barred spiral galaxy|bar formation]] and has tightly wound spiral arms with a ring-like structure around the nucleus.<ref name=vaucoulerus1991/> It has no nearby companion galaxies.<ref name=Jore1996/>

This is a [[Seyfert galaxy|Seyfert 1.9 galaxy]] with an [[active galactic nucleus]], having [[Radio astronomy|radio emissions]] detected in its nuclear region. Two radio sources have been detected, with the eastern component being the brighter at 1.0 [[Jansky|mJy]] while the fainter source is emitting 0.75 mJy. This radiation is most likely coming from [[Astrophysical jet|jets]] of energetic material being ejected by a central [[supermassive black hole|black hole]].<ref name=mnras426_1_588/>

In 1996 it was revealed that this galaxy has a counter-rotating disk; around 20% of the stars in the galaxy are rotating in the opposite direction from the other 80%.<ref name=Jore1996/> The neutral and ionized gas in this galaxy are rotating in the same direction as the counter-rotating disk, and the stars in this group are generally younger than the main stellar population. This disk may have formed as the result of a merger with a gas-rich [[dwarf galaxy]] some four billion years ago. Simulations indicate that the counter-rotation of this disk is acting to suppress spiral arm features in the galaxy as a whole. The young, star-forming ring structure is likely the result of collisions between gas clouds rotating in the opposite directions.<ref name=aa570_A79/>

== Gallery ==
<gallery class="center" widths="175">
File:NGC4138 - SDSS DR14.jpg|NGC 4138  (SDSS DR14)

File:NGC 4138 hst 06837 G547.png|NGC 4138  (HST)
</gallery>

== References ==
{{reflist|refs=

<ref name="ApJ131_1163">{{cite journal |doi=10.1086/498708 |last1=Skrutskie |first1=Michael F. |last2=Cutri |first2=Roc M. |last3=Stiening |first3=Rae |last4=Weinberg |first4=Martin D. |last5=Schneider |first5=Stephen E. |last6=Carpenter |first6=John M. |last7=Beichman |first7=Charles A. |last8=Capps |first8=Richard W. |last9=Chester |first9=Thomas |last10=Elias |first10=Jonathan H. |last11=Huchra |first11=John P. |last12=Liebert |first12=James W. |last13=Lonsdale |first13=Carol J. |last14=Monet |first14=David G. |last15=Price |first15=Stephan |last16=Seitzer |first16=Patrick |last17=Jarrett |first17=Thomas H. |last18=Kirkpatrick |first18=J. Davy |last19=Gizis |first19=John E. |last20=Howard |first20=Elizabeth V. |last21=Evans |first21=Tracey E. |last22=Fowler |first22=John W. |last23=Fullmer |first23=Linda |last24=Hurt |first24=Robert L. |last25=Light |first25=Robert M. |last26=Kopan |first26=Eugene L. |last27=Marsh |first27=Kenneth A. |last28=McCallon |first28=Howard L. |last29=Tam |first29=Robert |last30=Van Dyk |first30=Schuyler D. |last31=Wheelock |first31=Sherry L. |title=The Two Micron All Sky Survey (2MASS) |journal=The Astronomical Journal |date=1 February 2006 |volume=131 |pages=1163–1183 |url=https://ui.adsabs.harvard.edu/abs/2006AJ....131.1163S/abstract |issn=0004-6256 }}</ref>

<ref name=aj146_86>{{citation
 | display-authors=1
 | last1=Tully | first1=R. Brent | last2=Courtois | first2=Hélène M.
 | last3=Dolphin | first3=Andrew E. | last4=Fisher | first4=J. Richard
 | last5=Héraudeau | first5=Philippe | last6=Jacobs | first6=Bradley A.
 | last7=Karachentsev | first7=Igor D. | last8=Makarov | first8=Dmitry
 | last9=Makarova | first9=Lidia | last10=Mitronova | first10=Sofia
 | last11=Rizzi | first11=Luca | last12=Shaya | first12=Edward J.
 | last13=Sorce | first13=Jenny G. | last14=Wu | first14=Po-Feng 
 | title=Cosmicflows-2: The Data
 | journal=The Astronomical Journal
 | volume=146 | issue=4 | id=86 | pages=25 | date=October 2013
 | doi=10.1088/0004-6256/146/4/86 
 | bibcode=2013AJ....146...86T 
 | postscript = .
|arxiv = 1307.7213 | s2cid=118494842 }}</ref>

<ref name=Jore1996>{{citation
 | display-authors=1
 | last1=Jore | first1=Katherine P.
 | last2=Broeils | first2=Adrick H.
 | last3=Haynes | first3=Martha P. 
 | title=A Counter-Rotating Disk in the Normal SA Galaxy NGC 4138 
 | journal=Astronomical Journal
 | volume=112 | pages=438 | date=August 1996
 | doi=10.1086/118027 
 | bibcode=1996AJ....112..438J 
 | postscript=.
}}</ref>

<ref name=GAXEL>{{citation
 | display-authors=1 | last1=Gil de Paz | first1=Armando
 | last2=Boissier | first2=Samuel | last3=Madore | first3=Barry F.
 | last4=Seibert | first4=Mark | last5=Joe | first5=Young H.
 | last6=Boselli | first6=Alessandro | last7=Wyder | first7=Ted K.
 | last8=Thilker | first8=David | last9=Bianchi | first9=Luciana
 | last10=Rey | first10=Soo-Chang | last11=Rich | first11=R. Michael
 | last12=Barlow | first12=Tom A. | last13=Conrow | first13=Tim
 | last14=Forster | first14=Karl | last15=Friedman | first15=Peter G.
 | last16=Martin | first16=D. Christopher | last17=Morrissey | first17=Patrick
 | last18=Neff | first18=Susan G. | last19=Schiminovich | first19=David
 | last20=Small | first20=Todd | last21=Donas | first21=José
 | last22=Heckman | first22=Timothy M. | last23=Lee | first23=Young-Wook
 | last24=Milliard | first24=Bruno | last25=Szalay | first25=Alex S.
 | last26=Yi | first26=Sukyoung
 | title=The GALEX Ultraviolet Atlas of Nearby Galaxies
 | journal=[[Astrophysical Journal Supplement Series]]
 | volume=173 | issue=2 | pages=185–255 | date=2007
 | arxiv=astro-ph/0606440
 | doi=10.1086/516636
 | bibcode = 2007ApJS..173..185G
 | s2cid=119085482 | postscript=.
}}</ref>

<ref name=vaucoulerus1991>{{citation
 | display-authors=1 | last1=de Vaucouleurs | first1=G.
 | last2=de Vaucouleurs | first2=A. | last3=Corwin | first3=H. G., Jr.
 | last4=Buta | first4=R. J. | last5=Paturel | first5=G.
 | last6=Fouque | first6=P.
 | title=Third reference catalogue of bright galaxies, version 9
 | date=1991 | url=https://heasarc.gsfc.nasa.gov/W3Browse/all/rc3.html
 | access-date=2015-11-25
 | bibcode=1994AJ....108.2128C
 | postscript=.
|doi = 10.1086/117225 | volume=108 | journal=The Astronomical Journal | pages=2128}}</ref>

<ref name=mnras426_1_588>{{citation
 | display-authors=1
 | last1=Bontempi | first1=P.
 | last2=Giroletti | first2=M.
 | last3=Panessa | first3=F.
 | last4=Orienti | first4=M.
 | last5=Doi | first5=A.
 | title=Physical properties of the nuclear region in Seyfert galaxies derived from observations with the European VLBI Network 
 | journal=Monthly Notices of the Royal Astronomical Society
 | volume=426 | issue=1 | pages=588–594 | date=October 2012
 | doi=10.1111/j.1365-2966.2012.21786.x 
 | bibcode=2012MNRAS.426..588B | arxiv=1208.0230
 | s2cid=118387189 | postscript=.
}}</ref>

<ref name=aa570_A79>{{citation
 | display-authors=1
 | last1=Pizzella | first1=A. | last2=Morelli | first2=L.
 | last3=Corsini | first3=E. M. | last4=Dalla Bontà | first4=E.
 | last5=Coccato | first5=L. | last6=Sanjana | first6=G. 
 | title=The difference in age of the two counter-rotating stellar disks of the spiral galaxy NGC 4138 
 | journal=Astronomy & Astrophysics
 | volume=570 | id=A79 | pages=5 | date=October 2014
 | doi=10.1051/0004-6361/201424746 
 | bibcode=2014A&A...570A..79P
 | arxiv=1409.3086
 | s2cid=119276440 | postscript=.
}}</ref>

<ref name=SIMBAD>{{citation
 | title=NGC 4138 -- Seyfert 1 Galaxy 
 | work=SIMBAD Astronomical Database
 | publisher=[[Centre de Données astronomiques de Strasbourg]]
 | url=http://simbad.u-strasbg.fr/simbad/sim-id?Ident=NGC+4138
 | access-date=2015-11-30
 | postscript=.
}}</ref>

}}

== External links ==
* {{commons category-inline}}

{{Catalogs|NGC=4138|UGC=7139}}
{{Ngc45}}
{{Canes Venatici}}

{{DEFAULTSORT:NGC 4138}}
[[Category:Lenticular galaxies]]
[[Category:Seyfert galaxies]]
[[Category:Canes Venatici]]
[[Category:NGC objects|4138]]
[[Category:UGC objects|7139]]
[[Category:Ursa Major Cluster]]


{{lenticular-galaxy-stub}}