View source for NGC 4565

{{Short description|Galaxy in the constellation Coma Berenices}}
{{Infobox Galaxy
| name = [[New General Catalogue|NGC]] 4565
| image = Needle Galaxy 4565.jpeg
| image_size = 300px
| caption = NGC 4565
| epoch = [[J2000]]
| type = SA(s)b?<ref name="ned">{{cite web
| title=Results for NGC 4565
| work=NASA/IPAC Extragalactic Database
| url=http://nedwww.ipac.caltech.edu/cgi-bin/nph-objsearch?objname=NGC+4565&img_stamp=yes&extend=no
| access-date=2006-10-12 }}</ref>
| ra = {{RA|12|36|20.8}}<ref name="ned"/>
| dec = {{DEC|+25|59|16}}<ref name="ned"/>
| z = 0.004103<ref name=ned/>
| h_radial_v = {{nowrap|1230 ± 5 [[Metre per second|km/s]]}}<ref name=ned/>
| dist_ly = 42.7 ± 12 M[[light-year|ly]] (13.1 ± 3.7 M[[parsec|pc]])<ref name="ned-dist">{{cite web
| title=Distance Results for NGC 4565
| work=NASA/IPAC Extragalactic Database
| url=http://nedwww.ipac.caltech.edu/cgi-bin/nDistance?name=NGC+4565
| access-date=2010-05-02}}</ref><br/>[[1 E23 m|53 ± 4]] [[light-year|Mly]] (16.2 ± 1.3 [[parsec|Mpc]])<ref name="jensenetal2003">{{cite journal
| author=Jensen, Joseph B. | display-authors=4 | author2=Tonry, John L. | author3=Barris, Brian J. | author4=Thompson, Rodger I. | author5=Liu, Michael C. | author6=Rieke, Marcia J. | author7=Ajhar, Edward A. | author8=Blakeslee, John P.
| title=Measuring Distances and Probing the Unresolved Stellar Populations of Galaxies Using Infrared Surface Brightness Fluctuations
| journal=Astrophysical Journal
|date=February 2003
| volume=583
| issue=2
| pages=712–726
| bibcode=2003ApJ...583..712J
| doi=10.1086/345430
| arxiv = astro-ph/0210129 | s2cid=551714 }}</ref>
| appmag_v = 10.42<ref name="ned"/>
| size_v = 15.90{{prime}} × 1.85{{prime}}<ref name="ned"/>
| constellation name = [[Coma Berenices]]
| names = [[Uppsala General Catalogue|UGC]] 7772,<ref name="ned"/> [[Principal Galaxies Catalogue|PGC]] 42038,<ref name="ned"/> [[Caldwell catalogue|Caldwell]]&nbsp;38
}}
'''NGC 4565''' (also known as the '''Needle Galaxy''' or '''Caldwell 38''') is an edge-on [[spiral galaxy]] about 30 to 50 million [[light-year]]s away in the [[constellation]] [[Coma Berenices]].<ref name=ned-dist/> It lies close to the [[North Galactic Pole]] and has a [[visual magnitude]] of approximately 10.  It is known as the Needle Galaxy for its narrow profile.<ref name="apod-040409">{{cite web|url=http://apod.nasa.gov/apod/ap040409.html|title=NGC4565 at |website=apod.nasa.gov}}</ref> First recorded in 1785 by [[William Herschel]], it is a prominent example of an edge-on spiral galaxy.<ref>Spiral Galaxy NGC 4565 at http://www.eso.org/public/images/eso0525a/</ref>
== Characteristics ==
NGC 4565 is a giant spiral galaxy more luminous than the [[Andromeda Galaxy]].<ref name="Harrisglobulars">[http://ned.ipac.caltech.edu/level5/Harris/Harris2.html#Table%201 Globular Cluster Systems in Galaxies Beyond the Local Group]</ref>  Much speculation exists in literature as to the nature of the central bulge. In the absence of clear-cut dynamical data on the motions of stars in the bulge, the photometric data alone cannot adjudge among various options put forth. However, its exponential shape suggested that it is a [[barred spiral galaxy]].<ref>{{cite journal|url=https://iopscience.iop.org/article/10.1086/338849|title=Intermediate-band surface photometry of the edge-on galaxy NGC 4565|journal=The Astronomical Journal|date=2002 |doi=10.1086/338849 |last1=Wu |first1=Hong |last2=Burstein |first2=David |last3=Deng |first3=Zugan |last4=Zhou |first4=Xu |last5=Shang |first5=Zhaohui |last6=Zheng |first6=Zhongyuan |last7=Chen |first7=Jiansheng |last8=Su |first8=Hongjun |last9=Windhorst |first9=Rogier A. |last10=Chen |first10=Wen-Ping |last11=Zou |first11=Zhenlong |last12=Xia |first12=Xiaoyang |last13=Jiang |first13=Zhaoji |last14=Ma |first14=Jun |last15=Xue |first15=Suijian |last16=Zhu |first16=Jin |last17=Cheng |first17=Fuzhen |last18=Byun |first18=Yong-Ik |last19=Chen |first19=Rui |last20=Deng |first20=Licai |last21=Fan |first21=Xiaohui |last22=Fang |first22=Li-Zhi |last23=Kong |first23=Xu |last24=Li |first24=Yong |last25=Lin |first25=Weipeng |last26=Lu |first26=Phillip |last27=Sun |first27=Wei-Hsin |last28=Tsay |first28=Wean-Shun |last29=Xu |first29=Wen |last30=Yan |first30=Haojing |volume=123 |issue=3 |pages=1364–1380 |arxiv=astro-ph/0111433 |bibcode=2002AJ....123.1364W |display-authors=1 }}</ref> Studies with the help of the [[Spitzer Space Telescope]] not only confirmed the presence of a central bar but also showed a [[Galactic bulge|pseudobulge]] within it as well as an inner ring.<ref name="Spitzer">[http://adsabs.harvard.edu/abs/2009ASPC..419..149B Detection of a Distinct Pseudobulge Hidden Inside the ''Box-Shaped Bulge'' of NGC 4565]</ref>
NGC 4565 has at least two [[satellite galaxies]], one of which is [[interacting galaxies|interacting]] with it.<ref name="HALOGAS">[http://adsabs.harvard.edu/abs/2012ApJ...760...37Z HALOGAS: H I Observations and Modeling of the Nearby Edge-on Spiral Galaxy NGC 4565]</ref>  It has a population of roughly 240 [[globular cluster]]s, more than the [[Milky Way]].<ref name="Harrisglobulars" />
NGC 4565 is one of the brightest<ref name=":0">{{Cite web|url=https://www.webbdeepsky.com/galaxies/object?object=NGC4565|title=Webb Deep-Sky Society: Galaxy of the Month: NGC4565|website=www.webbdeepsky.com|language=en|access-date=2018-05-20}}</ref> member galaxies of the [[Coma I Group]].<ref>{{Cite journal|last1=Gregory|first1=Stephen A.|last2=Thompson|first2=Laird A.|date=April 1977|title=The Coma i Galaxy Cloud|bibcode=1977ApJ...213..345G|journal=The Astrophysical Journal|language=en|volume=213|pages=345–350|doi=10.1086/155160|issn=0004-637X}}</ref><ref name=":0" />
This edge-on galaxy exhibits a slightly warped and extended disk under deep optical surveys, likely due to ongoing interactions with neighboring satellite galaxies or other galaxies in the Coma I group. GALEX images show the slight warp at the edge of the disc more clearly than other surveys.
Using the [[Low-Frequency Array (LOFAR)|LOw-Frequency ARray]] (LOFAR), astronomers of the [[University of Hamburg]] discovered a diffuse [[radio halo]] around NGC 4565. During the observations, a warp was detected in the radio continuum of NGC 4565 that is reminiscent of a [[Hydrogen line|neutral hydrogen line]] (HI) warp and identifying a slight flaring of the galaxy's radio halo. It is assumed that this flaring is caused by the warp as the vertical intensity profiles are asymmetric, which is in agreement with the warp. According to the study, a minimum age for the warp was estimated at approximately 130 million years. This is the spectral age of the galaxy's [[cosmic ray]] electrons, during which they are transported into the warp. This indicates that NGC 4565 may be in the aftermath of a period with more intense [[star formation]].
[[File:Caldwell 38.jpg|thumb|A detailed view of part of the disc of the spiral galaxy NGC 4565 imaged by the [[Hubble Space Telescope]]]]
== References ==
{{reflist}}
== External links ==
* {{commonscatinline}}
* {{WikiSky}}
* [http://www.noao.edu/outreach/aop/observers/n4565.html National Optical Astronomical Observatory] {{Webarchive|url=https://web.archive.org/web/20090522041947/http://www.noao.edu/outreach/aop/observers/n4565.html |date=2009-05-22 }} – NGC 4565
* [https://apod.nasa.gov/apod/ap240606.html APOD (2024-06-06)] - NGC 4565: Galaxy on Edge
* [http://apod.nasa.gov/apod/ap100304.html APOD (2010-03-04)] – NGC 4565: Galaxy on Edge
* [http://apod.nasa.gov/apod/ap090428.html APOD (2009-04-28)] – NGC 4565
* [http://messier.seds.org/xtra/ngc/n4565.html SEDS] – NGC 4565
{{Sky|12|36|20.8|+|25|59|16|53000000}}
{{Catalogs | C = 38 | NGC = 4565 | UGC = 7772 | PGC = 42038}}
{{Caldwell catalogue}}
{{Ngc50}}
{{Coma Berenices}}
{{Portal bar|Astronomy|Stars|Spaceflight|Outer space|Solar System}}
{{DEFAULTSORT:NGC 4565}}
[[Category:Unbarred spiral galaxies]]
[[Category:Coma Berenices]]
[[Category:NGC objects|4565]]
[[Category:UGC objects|07772]]
[[Category:Principal Galaxies Catalogue objects|42038]]
[[Category:Caldwell objects|038b]]
[[Category:Astronomical objects discovered in 1785]]
[[Category:Discoveries by William Herschel]]
[[Category:Coma I Group]]