NGC 4625

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NGC 4625
NGC4625 - HST - Potw1746a.tif
Observation data (J2000 epoch)
Constellation Canes Venatici [1]
Right ascension 12h 41m 52.7s [2]
Declination +41° 16 26 [2]
Redshift 609 ± 1 km/s [2]
Apparent magnitude  (V)13.2g [2]
Characteristics
Type SAB(rs)m pec [2]
Apparent size  (V)1.3 × 1.2 [2]
Notable featuresAsymmetric; Single spiral arm [3]
Other designations
IC 3675, [2] UGC 7861, [2] PGC 42607 [2]

NGC 4625 is a distorted dwarf galaxy in the constellation Canes Venatici. The galaxy is formally classified as a Sm galaxy, which means that its structure vaguely resembles the structure of spiral galaxies. The galaxy is sometimes referred to as a Magellanic spiral because of its resemblance to the Large Magellanic Cloud's single-arm structure.

Contents

Structure

An ultraviolet image of NGC 4625 taken with GALEX shows a disc four times larger than what is seen in visible light NGC 4625 I FUV g2006.jpg
An ultraviolet image of NGC 4625 taken with GALEX shows a disc four times larger than what is seen in visible light

Unlike most spiral galaxies, NGC 4625 has a single spiral arm, which gives the galaxy an asymmetric appearance. [3] It has been hypothesized that this galaxy's asymmetric structure may be the result of a gravitational interaction with NGC 4618. [3] Such asymmetric structure is commonly seen among many interacting galaxies. However, observations of neutral hydrogen gas in NGC 4618 and NGC 4625 show that NGC 4625 does not appear to have been affected by the gravitational interaction. [4] This indicates that the single-arm structure seen in NGC 4625 may be created through intrinsic processes.

Ultraviolet observations of NGC 4625 made by the Galaxy Evolution Explorer (GALEX) show the presence of an extended disk. The new spiral disk extrends 28,000 light-years from the galaxy center, a staggering four times the optical radius. The hot blue stars in this new disk may have formed from the inflow of fresh gas and dust from interaction with its companions, NGC 4618 and NGC 4625A. [5] The UV-to-optical colors suggest that the bulk of the stars in the disk of NGC 4625 are currently being formed, providing a unique opportunity to study today the physics of star formation under conditions similar to those when the normal disks of spiral galaxies like the Milky Way first formed. [6]

Environment

As mentioned above, NGC 4625 is interacting with NGC 4618. [3]

See also

Related Research Articles

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The Pinwheel Galaxy is a face-on, unbarred, and counterclockwise spiral galaxy located 21 million light-years from Earth in the constellation Ursa Major. It was discovered by Pierre Méchain in 1781 and was communicated that year to Charles Messier, who verified its position for inclusion in the Messier Catalogue as one of its final entries.

<span class="mw-page-title-main">Messier 63</span> Spiral galaxy in the constellation Canes Venatici

Messier 63 or M63, also known as NGC 5055 or the seldom-used Sunflower Galaxy, is a spiral galaxy in the northern constellation of Canes Venatici with approximately 400 billion stars. M63 was first discovered by the French astronomer Pierre Méchain, then later verified by his colleague Charles Messier on June 14, 1779. The galaxy became listed as object 63 in the Messier Catalogue. In the mid-19th century, Anglo-Irish astronomer Lord Rosse identified spiral structures within the galaxy, making this one of the first galaxies in which such structure was identified.

<span class="mw-page-title-main">NGC 4565</span> Galaxy in the constellation Coma Berenices

NGC 4565 is an edge-on spiral galaxy about 30 to 50 million light-years away in the constellation Coma Berenices. 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. First recorded in 1785 by William Herschel, it is a prominent example of an edge-on spiral galaxy.

<span class="mw-page-title-main">Eyes Galaxies</span> Pair of galaxies in the constellation Virgo

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<span class="mw-page-title-main">NGC 6872</span> Galaxy in the constellation Pavo

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<span class="mw-page-title-main">NGC 5033</span> Galaxy in the constellation Canes Venatici

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<span class="mw-page-title-main">NGC 5713</span> Peculiar and asymmetric galaxy in the constellation Virgo

NGC 5713 is a peculiar, asymmetric galaxy in the constellation Virgo. Although classified as a spiral galaxy by most galaxy catalogs, NGC 5713 is very different from most normal spiral galaxies. While most spiral galaxies either have either two well-defined spiral arms or a filamentary spiral-like structure, this spiral galaxy has only one visible spiral arm in its disk. This makes it a galaxy of the Magellanic type. Gravitational interactions with the nearby spiral galaxy NGC 5719 may be responsible for producing the disturbed, asymmetric structure including the single spiral arm.

<span class="mw-page-title-main">NGC 5005</span> Galaxy in the constellation Canes Venatici

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<span class="mw-page-title-main">NGC 4618</span> Distorted dwarf barred spiral galaxy in the constellation Canes Venatici

NGC 4618 is a distorted barred dwarf galaxy in the constellation Canes Venatici. The galaxy is formally classified as a Sm galaxy, which means that its structure vaguely resembles the structure of spiral galaxies. The galaxy is sometimes referred to as a Magellanic spiral because of its resemblance to the Magellanic clouds.

<span class="mw-page-title-main">NGC 4449</span> Galaxy in the constellation Canes Venatici

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The H I Parkes All Sky Survey (HIPASS) is a large survey for neutral atomic hydrogen (H I). Most of the data was taken between 1997 and 2002 using CSIRO's 64 m Parkes Telescope. HIPASS covered 71% of the sky and identified more than 5000 galaxies; the major galaxy catalogs are: the "HIPASS Bright Galaxy Catalog", the southern HIPASS catalog (HICAT), and the northern HIPASS catalog (NHICAT) Discoveries include over 5000 galaxies, the Leading Arm of the Magellanic Stream and a few gas clouds devoid of stars.

<span class="mw-page-title-main">NGC 3169</span> Galaxy in the constellation Sextans

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<span class="mw-page-title-main">NGC 925</span> Galaxy in the constellation Triangulum

NGC 925 is a barred spiral galaxy located about 30 million light-years away in the constellation Triangulum. The morphological classification of this galaxy is SB(s)d, indicating that it has a bar structure and loosely wound spiral arms with no ring. The spiral arm to the south is stronger than the northern arm, with the latter appearing flocculent and less coherent. The bar is offset from the center of the galaxy and is the site of star formation all along its length. Both of these morphological traits—a dominant spiral arm and the offset bar—are typically characteristics of a Magellanic spiral galaxy. The galaxy is inclined at an angle of 55° to the line of sight along a position angle of 102°.

A Magellanic spiral galaxy is a spiral galaxy with only one spiral arm. Magellanic spiral galaxies are classified as the type Sm ; the prototype galaxy and namesake for Magellanic spirals is the Large Magellanic Cloud, an SBm galaxy. They are usually smaller dwarf galaxies and can be considered to be intermediate between dwarf spiral galaxies and irregular galaxies.

<span class="mw-page-title-main">NGC 3860</span> Spiral galaxy in the constellation Leo

NGC 3860 is a spiral galaxy located about 340 million light-years away in the constellation Leo. NGC 3860 was discovered by astronomer William Herschel on April 27, 1785. The galaxy is a member of the Leo Cluster and is a low-luminosity AGN (LLAGN). Gavazzi et al. however classified NGC 3860 as a strong AGN which may have been triggered by a supermassive black hole in the center of the galaxy.

<span class="mw-page-title-main">NGC 7469</span> Galaxy located in the constellation Pegasus

NGC 7469 is an intermediate spiral galaxy in the constellation of Pegasus. NGC 7469 is located about 200 million light-years away from Earth, which means, given its apparent dimensions, that NGC 7469 is approximately 90,000 light-years across. It was discovered by William Herschel on November 12, 1784.

<span class="mw-page-title-main">NGC 7130</span> Galaxy in the constellation Piscis Austrinus

NGC 7130 is a spiral galaxy located in the constellation Piscis Austrinus. It is located at a distance of about 220 million light years from Earth, which, given its apparent dimensions, means that NGC 7130 is about 100,000 light years across. It was discovered by John Herschel on September 25, 1834, and discovered independently by Lewis Swift on September 17, 1897. The location of the galaxy given in the New General Catalogue was off by 30 arcminutes in declination from the location of the galaxy.

<span class="mw-page-title-main">NGC 4294</span> Galaxy in the constellation Virgo

NGC 4294 is a barred spiral galaxy with flocculent spiral arms located about 55 million light-years away in the constellation Virgo. The galaxy was discovered by astronomer William Herschel on March 15, 1784 and is a member of the Virgo Cluster.

<span class="mw-page-title-main">NGC 4299</span> Spiral galaxy in the constellation Virgo

NGC 4299 is a featureless spiral galaxy located about 55 million light-years away in the constellation Virgo. It was discovered by astronomer William Herschel on March 15, 1784 and is a member of the Virgo Cluster.

<span class="mw-page-title-main">NGC 4302</span> Galaxy in the constellation Coma Berenices

NGC 4302 is an edge-on spiral galaxy located about 55 million light-years away in the constellation Coma Berenices. It was discovered by astronomer William Herschel on April 8, 1784 and is a member of the Virgo Cluster.

References

  1. R. W. Sinnott, ed. (1988). The Complete New General Catalogue and Index Catalogue of Nebulae and Star Clusters by J. L. E. Dreyer. Sky Publishing Corporation and Cambridge University Press. ISBN   978-0-933346-51-2.
  2. 1 2 3 4 5 6 7 8 9 "NASA/IPAC Extragalactic Database". Results for NGC 4625. Retrieved 2006-12-07.
  3. 1 2 3 4 A. Sandage; J. Bedke (1994). Carnegie Atlas of Galaxies. Washington, D.C.: Carnegie Institution of Washington. ISBN   978-0-87279-667-6.
  4. S. J. Bush; E. M. Wilcots (2004). "Neutral Hydrogen in the Interacting Magellanic Spirals NGC 4618 and NGC 4625". Astrophysical Journal. 128 (6): 2789–2796. arXiv: astro-ph/0409209 . Bibcode:2004AJ....128.2789B. doi:10.1086/425876. S2CID   14636586.
  5. Martin Ratcliffe (December 8, 2006). State of the Universe 2007: New Images, Discoveries, and Events. Google Books: Springer Praxis Books. p.  29. ISBN   978-0387341781.
  6. A. Gil de Paz; et al. (9 June 2005). "Discovery of an Extended Ultraviolet Disk in the Nearby Galaxy NGC 4625". The Astrophysical Journal Letters. 625 (1): 29–32. arXiv: astro-ph/0506357 . Bibcode:2005ApJ...627L..29G. doi:10.1086/432054. S2CID   55384358.